Empowering Global Innovation December 2008

Design Tips

Special Report - Renewable Energy ISSN: 1613-6365

Organic LED Drivers Dilbert – 64 Viewpoint Enhanced Image Quality, Energy-Effi cient Displays Gloom is not an option, By Cliff Keys, Editor-in-Chief, PSDE...... 4

High-Performance Analog>>Your Way™ Industry News Tony Armstrong Appointed as Linear’s Director of Product Marketing...... 6 CamSemi named ‘Start-Up of the Year’ 2008...... 6 Digi-Key Agreement with Tyco Expanded Worldwide...... 6 Applications Incorporated Wins Environmental Award...... 8 Fuji Electric and Semikron Team-Up...... 8 – OLED displays up to 2.5” Inauguration of Solar Roof at Goethe-Institut, Bangalore...... 8 – CCD sensor bias – Positive and negative Optimized Control in Renewables...... 10 analog supplies L1 2.2 µH – Active Matrix OLED (AMOLED) power supplies 16 14 Smart Solar Energy Management Drives Solar Adoption, By Ralf J. Muenster, National ...... 12 and displays used in mobile L1 L2 VIN 15 13 phones L1 L2 2.5 V to 5.5 V 1 10 VIN OUTP VPOS C1 8 9 C2 4.6 V/80 mA – Mobile internet devices EN OUTP 10 µF 4.7 µF Sellers’ Market for Photovoltaic Raw Materials to Shift in Buyers’ Favor in 2009, By Marijana Vukicevic, iSuppi...... 13 4 7 – Portable media players and VAUX FB 11 6 digital cameras C4 PGND FBG R1 Design Tips 12 3 464 kΩ 100 nF PGND OUTN Power Supply Reliability, By Dr. Ray Ridley, Ridley Engineering...... 15 5 C3 Features GND OUTN 2 4.7 µF R2 – 2.3-V to 5.5-V input voltage 442 kΩ On The Road TPS65136 VNEG , Infineon Technologies, International , Intersil, , Sharp Microelectronics, Instruments, Vishay range -4.4 V/80 mA Intertechnology, Reported by Cliff Keys, Editor-in-Chief, PSDE...... 20 – Fixed positive output voltage of 4.6 V The TPS65136, part of TI’s OLED driver portfolio, enhances the image – Negative output voltage down quality for Active Matrix OLED displays used in portable applications. Energy-Efficiency: Walking the Talk, Reported by Cliff Keys, Editor-in-Chief, PSDE...... 31 APEC 2009, Washington DC, February 15-19th, Reported by Cliff Keys, Editor-in-Chief PSDE...... 32 to -7 V Based on TI’s single-inductor output regulator technology, the OLED driver supports positive and negative voltages, and achieves the smallest Power Sensitivity in Design makes Networking Green, Reported by Cliff Keys, Editor-in-Chief PSDE...... 33 – Short circuit protection solution size using a single inductor. Cover Story – Superior line regulation Speed and Precision in Gate Drives, By Sascha Pawel and Jan Thalheim, CT-Concept Technologies...... 34 – Buck-boost mode for both IOUT Output Device VIN (V) VOUT (V) (A) (typ) Effi ciency (%) Package Power Supplies outputs TPS65130 2.7 to 5.5 –15 to 15 0.8 89 24-pin QFN High-Power, High-Density Power Supply with Optimum Thermal Performance, By Afshin Odabaee and Alan Chern, Linear Technology...... 38 – Supports new batteries with TPS65131 2.7 to 5.5 –15 to 15 1.95 89 24-pin QFN Distributed Power Architecture, By Paul Greenland, Semtech...... 43 input voltages up to 4.8 V TPS65136 2.3 to 5.5 –6 to 4.6 0.7 70 16-pin QFN Special Report: Renewable Energy Industrial Fiber Optics in Renewables, By Alek Indra, Avago Technologies...... 48 Minimize Losses in Solar Panels, By Ian Moulding, Diodes Incorporated...... 51 Democratizing Solar, By Nasser Kutkut, Petra Solar, Inc...... 54 Reliability in Renewables, Reported by Cliff Keys, Editor-in-Chief, PSDE...... 57 www.ti.com/tps65136-e or call toll free: Renewable Energy Efficiency, By Arefeen Mohammed, C2000 Systems & Applications Engineer Houston, Texas...... 59 00800-ASKTEXAS (00800 275 83927) or international: +49 (0) 8161 80 2121 Get Datasheets, Evaluation Modules, Samples and the Power Management Selection Guide Progress vs. Politics, Reported by Cliff Keys, Editor-in-Chief, PSDE...... 64

Power Systems Design Europe Advisory Board Member Representing Member Representing Arnold Alderman Anagenesis Andrew Cowell Micrel Heinz Rüedi CT-Concept Technology Michele Sclocchi National Semiconductor Marion Limmer Mike Noonen NXP Eric Lidow Industry Luminary Kirk Schwiebert Ohmite High-Performance Analog>>Your Way and the platform bar are trademarks of Texas Instruments. 2168A1 © 2008TI Dr. Reinhold Bayerer Infineon Technologies Christophe Basso On Semiconductor Dr. Leo Lorenz Infineon Technologies Balu Balakrishnan Power Integrations Davin Lee Intersil Paul Greenland Semtech Tony Armstrong Linear Technology Uwe Mengelkamp Texas Instruments Hans D. Huber LEM Peter Sontheimer Tyco Electronics

AD#: 2168A1 File Name: P82168_TI_PSDe_7-14.indd JWT Communications, Entertainment & Technology One Ravinia Dr. Pubs: Power Systems Design Europe Atlanta, GA 30346 Insertion Date: July/August 2008 (New Materials) Position: Page 9 Gabrielle Seaborne 770.668.5700 x258 Size: Bleed: 303 x 216 [email protected] Trim: 297 x 210 Live: 263 x 184

Materials: E-Mail a 300 dpi PDF format to: [email protected] VIEWPOINT

Gloom is not an option

more severe 9.9%. Following 2009, auto sales in the United States and Europe are expected to begin a slow recovery. The situation is not expected to improve in the near future, with U.S. and Western European sales not expected to recover to 2007 levels for five or six years.

This is a grim picture indeed, even for our industry, but for sure there will be a revolution in the power technology used here. One of the harshest criticisms of the auto industry has been that it kept on doing what it was good at; producing We find ourselves now right at the the same old stuff without embracing the start of the forthcoming calendar year, new ideas and technologies available. although I’m still wondering what Let’s hope things move forward here happened to the year – it went so fast. faster than predicted. I’m not going to devote valuable space and bore everyone rigid in the process, Aside from the economic reports of with a detailed look back but would doom and gloom, the fact is we have an instead rather look forward. Even though industry poised to achieve even greater we are facing, or indeed in, difficult things than ever before, and the need times, we have a very solid industry has never been so desperate. overall, and power has never had such a pivotal role to play in the well-being National’s boss, Brian Halla talks of our engineers, our industry and our about the ‘megatrends’ in the industry environment. reported in the ‘On-the-Road’ section of the magazine (also see my web This issue is themed on renewable exclusive extended electronica report by energy. For renewable energy I believe going to our home page and simply click we can read renewable opportunities, on the electronica logo), representing businesses, as well as environmental his vision for the opportunities in front of well-being. Sounds a bit corny? us rather than the ‘oh’s and woes’ in the Just consider the amount of good current thinking of some other leaders. engineering and management that This is just the kind of inspiration and supports this potentially vast industry. industry leadership we all need to fuel The solar modules seen cladding the the optimistic enthusiasm for which our tops of buildings these days, are rapidly industry is renowned and to keep the on the increase. So much so, that here spirit of innovation driving relentlessly in Germany it’s an accepted part of forward. the landscape. But just like with the proverbial ‘tip of the iceberg’ analogy, I hope you enjoy this very full issue, to there is so much more going on below check out the exclusive online reporting the visible part. A whole sector of our and electronica 2008 Roundup, go to industry is devoted to producing higher www.powersystemsdesign.com and efficiencies in power conversion, more simply click on the electronica logo. Also intelligent management of solar arrays, pay a visit to our fun-strip ‘Dilbert’ at the connections to the grid and now, back of the magazine and as ever, keep improvements in the panels themselves. your valuable feedback coming.

Turning towards the automotive sector, All the best! U.S. car sales in 2008 are set to drop by 17.7% compared to 2007, contributing to what is expected to be the worst year since 1980 for the global automotive industry, according to iSuppli Corp. A further worldwide decline representing a Editor-in-Chief, PSDE 6.5% decrease is projected for 2009. [email protected]

Western European sales will drop by a

 Power Systems Design December 2008 INDUSTRY NEWS

Tony Armstrong Appointed as Linear’s Director of Product Marketing

Tony Armstrong has been appointed consistent vision, in-depth market knowl- Director of Product Marketing for Power edge and a broad understanding of the high Products at Linear Technology. In this key performance analog business. I am extremely position, Armstrong has responsibility for the confident in Tony’s ability to lead our product management of all aspects of product market- marketing efforts in order to grow the busi- ing for integrated circuits as well as power ness going forward.” µModule™ regulators. Armstrong also takes full charge of product pricing, advertising and www.linear.com marketing campaign development. Armstrong brings a valuable 27 years of industry experience to his new role, includ- ing over eight years at Linear as Product Marketing Manager. Prior to joining Linear, he held key sales, marketing and management positions with major companies including Sili- conix, Semtech, Fairchild and . Armstrong holds a BS (Honors) in Applied Mathematics from the University of Manchester, England. According to Don Paulus, Vice President and General Manager of Linear Technology Power Products, “Tony has demonstrated

CamSemi named ‘Start-Up of the Year’ 2008 per year who in the judges’ view demonstrates efficiency has become a global priority: the the most exciting growth potential. The external company closed its C round funding in April to panel of industry experts reviews each candi- raise US $ 34 million; launched new control- date company on the strengths of its technol- lers to enable low cost, more energy-efficient ogy, business model, management team and power supplies for cordless phones; and has the market opportunity they are addressing. shipped 10 million chips from its first product CamSemi was awarded the honour at family. A number of further breakthrough per- the NMI Awards Dinner held on Thursday 6 formance products are also due for introduc- November in London. The photograph below tion over the next few months. shows from left to right: Derek Boyd, CEO of NMI; Rob Galuszka, Sales Director – North- www.camsemi.com ern Europe from , CamSemi has announced that it has been sponsors of the award category; and Ted Wig- named ‘NMI Start-up of the Year’ 2008 in the gans, VP Operations at CamSemi. UK’s National Microelectronics Institute (NMI) In accepting the award, Ted Wiggans com- 12th Anniversary Awards. This prestigious mented on CamSemi’s significant commercial award recognises one early-stage company progress this year at a time when energy

Digi-Key Agreement with Tyco Expanded Worldwide Digi-Key Corporation has announced that distribution agreement with Tyco Electronics. to our fastest growing markets in Europe it has recently expanded its current franchise Tyco Electronics’ reputation and history of and Asia."Digi-Key Corporation focuses on agreement with Tyco Electronics to a global bringing innovative products to the market is providing customers with superior service, authorization.Tyco Electronics is the world’s the perfect fit for the hundreds of thousands which includes product selection and avail- largest supplier of passive electronic compo- of design engineers we serve worldwide," ability, on-time delivery, and responsiveness. nents, which includes connectors and inter- said Mark Larson, Digi-Key president and Using streamlined processes and state-of- connection systems, relays, , circuit COO. "Digi-Key’s service advantage coupled the-art technologies, Digi-Key serves a global protection devices, touch screens, sensors with Tyco Electronics’ technology advantage customer base from its single 600,000 square and wire and cable. These products are used can do nothing but create a winning situa- foot facility in Thief River Falls, Minnesota, primarily in the automotive, computer, con- tion for a wide range of customers seeking to USA. sumer electronics, communication equipment, deliver new products to the market faster or www.digikey.com appliance, aerospace and defense, industrial improve the performance of existing products. machinery and instrumentation markets. "We This worldwide authorization will allow us to are very pleased to expand to this global offer Tyco Electronics’ leading edge products

 Power Systems Design December 2008 INDUSTRY NEWS

Diodes Incorporated Wins Environmental Award

Diodes Inc. has won the Environmental the business’s environmental performance. Award at the annual Elektra Awards held in Through workforce engagement and ‘buy-in’ Munich on the eve of Electronica 2008. Now to this vision, Diodes believes it is achieving in their sixth year, the Elektra Awards are ‘world class’ environmental performance.” regarded as the most prestigious electronic Diodes’ Elektra win follows hot on the heels product, technology and business awards in of another award, the National Microelectron- Europe and recognise the achievements of ics Institute’s Low Power “Green” Design individuals and companies throughout the Award for 2008. The award was made to European Electronics industry. Diodes for its ZXGD3101T8 MOSFET rectifier Receiving the award on behalf of Diodes controller. Incorporated, European President Colin Greene said, “We’re thrilled to receive this www.diodes.com Diodes Incorporated picks up the Elektra award as it really does recognise the incred- Environmental Award for 2008. Pictured left ible efforts of our Green Team, a volunteer to right are: The Master of Ceremony Sky group of employees, representative of the Sports Presenter Jeff Stelling, Colin Greene, entire organisation, with a real passion to see European President, Diodes Incorporated, environmental objectives achieved.” Martin Southam, Director of Marketing of the “Diodes Incorporated believes that one of award sponsor TDK-Lambda and Richard the most important ways to achieve environ- Wilson, Editor in Chief of event organisers mental recovery and sustainability is through Electronics Weekly. the continuous drive of its people to improve

Fuji Electric and Semikron Team-Up Fuji Electric Device Technology and Semi- Fuji Electric, both companies are expanding kron International have signed a supply and their product range to offer customers the licence agreement at Semikron in Nuremberg. optimum chip/module combination for a given Fuji Electric will supply IGBT semiconductor application. By using the same spring contact chips to SEMIKRON; in return Semikron will technology Fuji Electric and SEMIKRON are supply Fuji Electric with freewheeling and able to increase the market penetration for rectifier chips, and module cases in industrial drives, power supplies and home spring contact technology. Power modules appliances. This matches the second source with spring contacts will be manufactured by policy of customers. Fuji Electric under licence. Under this co-operation, the two compa- www.fujielectric.com and www. Dirk Heidenreich, CEO of Semikron Interna- nies are forging the basis for mutual supply fujielectric.com/device/semi tional and Dr. Hisao Shigekane, President of power semiconductor chips. With the new and Representative Director of Fuji Electric freewheeling diode and rectifier diode chips www.semikron.com Drive Technology sign the agreement from SEMIKRON and the IGBT chips from

Inauguration of Solar Roof at Goethe-Institut, Bangalore

Goethe-Institute/Max Mueller Bhavan in Ban- experts, including Professor Dr. Olav Hohm- galore, India. eyer, member of the U.N. Intergovernmental Udo Möhrstedt, IBC Solar AG Chairman Panel on Climate Change, who was awarded handed the system over to the head of the the Nobel Peace Prize in 2007 along with Al institute, Dr. Evelin Hust, in the presence of Gore, outlined the advantages of photovoltaic the Consul General of the Federal Republic of energy production for India. Germany, Mr. Stefan Graf. The project is part The demand for reliable energy is particu- financed by the dena Solar Roofs Programme larly high in India. Electricity cuts can be a and realized by German IBC SOLAR with regular occurrence and are a great challenge installation and maintenance support from for firms. Solar energy is one solution to this Selco India. problem. The PV system at Goethe-Institute/Max Mueller Bhavan is connected to the house The installed solar panels at the Goethe- www.ibc-solar.com grid and feeds the electricity into its grid. It Institut, Bangalore allows the institute to use the energy immedi- IBC Solar, the photovoltaic system integra- ately and, in the case of a grid disconnection, tor, together with the German Energy Agency the system switches instantly to backup mode (dena) held a ceremonial inauguration of the in order to directly supply the institute. photovoltaic installation on the roof of the During the inauguration event, a number of

 Power Systems Design December 2008 Optimized Control in Renewables New digital DC/DC converter from Ericsson

Renewable energies have to convert, in one way or another, voltages to a level required by controllers and monitoring functions. Without considering the whole chain, the benefits of renewable energies could be ruined by sub-functions using lower efficiency dc/dc converters, not able to optimize their efficiency to different load conditions.

he adaptive control and A synchronization facility enables digital power management multiple modules to operate at ex- Tembedded within Ericsson’s actly the same frequency to facili- BMR453, offering the most ad- tate optimum filter design for quiet vanced performances in terms of running – RF or conducted. A ‘power efficiency as well as control and good’ pin operates between active monitoring through its PMBus. low and active high and is a useful feature for event-based program- In addition, BMR453 has a built- ming, for example sequenced start- in auto-paralleling function, which ups. can make possible for the interme- diate bus to deliver twice power For current sharing duties, when needed, and to automatically BMR453 modules can be oper- to a single converter mode ated in parallel without the need while the second turned into sleep devices such as hard drives that cannot for external balancing circuitry. Instead, mode. The implementation of similar tolerate the wide variation in bus voltage dedicated pins are simply tied together functionalities to larger systems would provided by a normal IBC. The BMR453 and current sharing is automatic. A volt- let expect huge potential of energy sav- series is available both with and without age track pin will follow an external de-

ing, reducing CO2 emissions, and total a baseplate. A communication pin head- vice and again is used for event-based cost of ownership. er is used for connection to the PMBus. programming.

With 96% efficiency, the BMR453 of- Ericsson’s BMR453 modules feature a These extra features have all been fers up to 400W output power or up to PMBus interface for system connection, added to what was the previous 33A with ±2% accuracy. At that level of opening up a whole new world of con- standard for a DC/DC converter, and accuracy, the best module commercially trol features. The digital control system together with its unprecedented power available offers just 300W output power. provides users with access to control, density, the combination makes the So Ericsson’s BMR453 offers a huge configure and monitor the device itself. product truly unique. 33% more power in the same package This is a huge step forward for custom- size. Showing versatility, the BMR453 ers as this level of control has never An evaluation kit is available to help has an input voltage range of 36V to been available before, and these new designers evaluate and program the 75V, and its output voltage is variable capabilities allow for much more intel- modules. It comprises evaluation board, from 8.5V to 13.5V. ligent energy management that helps to operating manual, CD containing Graph- reduce energy consumption. ic User Interface (GUI) and cables. This Application areas for the BMR453 is the first quarter brick DC/DC con- series are also found in systems that For users that do not need to use the verter that can handle digital manage- must use a telecom input voltage with PMBus interface, an optional version is ment and for the first time it is possible battery backup or both -48V and -60V available without the communication pin to actually ‘see’ inside the module when nominal input voltages. Its inherent load header. The converters meet the insula- using a GUI, and track what is happen- regulation also allows the BMR453 to tion requirements of EN60950 and come ing in the converter. be used as an IBC in systems where the complete with vital industry standard www.ericsson.com/powermodules intermediate bus voltage directly powers features.

10 Power Systems Design December 2008 Smart Solar Energy Management Sellers’ Market for Drives Solar Adoption Photovoltaic Raw Materials Today’s solar inverters try to optimize the entire array from a central vantage point, which severely limits their effectiveness. National’s SolarMagicTM technology is revolutionizing photovoltaic systems by distributing intelligence in solar arrays. to Shift in Buyers’ Favor By Ralf J. Muenster, Director Renewable Energy Segment, National Semiconductor Corp.

nergy constraint is a global mega- able energy to its full potential. in 2009 trend. With increased demand Eand limited conventional sources, Over the past few years, researchers in By Marijana Vukicevic, iSuppli Corp. renewable energy is an increasingly criti- National Semiconductor’s labs have been cal component of our world economy. studying this problem. They realized that ricing for polysilicon used to “The PV supply chain is immature and Converting solar irradiation into electric- today’s inverters still happen to be the create Photovoltaic (PV) cells is inflexible, which will result in significant ity through the use of solar photovoltaic least reliable component in PV systems, expected to drop in 2009 and supply chain instability and waste,” (PV) technology is the most promising lasting only five to ten years. Panels, P the following years due to fundamental Wicht said. “iSuppli estimates that and under-represented alternative en- on the other hand, last about 25 years. imbalances in the solar supply chain, more than 90 percent of the existing PV ergy technology on the market. Today, Today’s panels feature solely passive according to iSuppli Corp. supply chain is characterized by fixed solar comprises less than 0.1 percent of electronics because nobody had man- supply agreements that are incapable the total energy production worldwide. aged to integrate smart, reliable, active Global supply of polysilicon is expect- of adjusting to actual changes in end- electronics. The main feature that needs ed to double in 2009, while demand demand. Continuing advances in PV technol- to be distributed in PV systems is an op- will grow by only 34 percent. Although ogy make this form of renewable energy timization function, which can be highly demand for polysilicon will still exceed Supply and demand will not be able particularly well-positioned for future integrated into a few sophisticated ICs. supply in aggregate in 2009, the sharp to maintain balance at the various growth. With many new production ca- It turns out that National has created and increase in supply will cause polysilicon nodes in the supply chain for any length pacities and new technologies entering delivered reliable ICs for very demanding pricing to begin a precipitous plunge in of time, resulting in substantial swings the market, 2009 could become a ban- applications for nearly 50 years. strings. If active, these bypass diodes will 2009 after peaking this year. in inventory and pricing over the next ner year for solar. One promising new reroute the current around big sections of two years, at which point polysilicon technology is a micro-optimizer tech- The advent of micro-optimizer tech- string, not only losing the potential energy Due to strong solar-driven de- supply will exceed demand so much nology, like National Semiconductor’s nology can make solar more efficient by contribution of these cells, but worse, mand that arose in 2005, suppliers that all contracts and sales channels SolarMagicTM technology, which makes monitoring and maximizing the energy lowering the overall voltage of that string. of silicon and wafers have been able will need to be redefined.” solar energy management smarter. harvest of each individual panel and to dictate pricing and contract terms to decline to as low as $100 per kilo- maximizing the energy flow through the Coming back to the concept of to customers during the past three gram in 2010. Mounting supply-chain problems Today, the typical solar photovoltaic in- array. SolarMagic technology, which maximum operating point for the cells, years. This situation hit a crescendo come at a time when the market is stallation consists of a number of carefully leverages National’s expertise and the inverter will now have to decide if in 2008, with spot market prices for “The dramatic variance in the ramp- undergoing rapid growth. Wafer-based matched panels that are connected in a competence in advanced algorithms it should optimize the voltage for the polysilicon rising as high as $500 per up rates of the polysilicon suppliers solar cell operational production capac- series of strings and put in parallel with combined with leading-edge mixed- impaired string or maximize the energy kilogram, up from as low as $200 in and their PV-cell customers will lead to ity will increase from 6.2 Gigawatts (GW) other series strings. The DC current gen- signal and power management technol- harvest from the non-impaired strings. 2007. The corresponding wafer price major supply-chain imbalances,” said in 2007 to 17.8 GW in 2010 and 27.5 erated by this array subsequently feeds ogy, allows solar installations to recoup In most cases, the inverter will choose rose to $13 per piece and higher in Henning Wicht, PhD, senior director GW in 2012, iSuppli predicts. However, into an inverter on the side of the array. up-to-50 percent of lost power due to to optimize for the non-impaired strings, 2008. and principal analyst, photovoltaics, for polysilicon production will rise even shading and panel mismatches. causing the energy harvest of the im- iSuppli. faster, with production equivalent to 5.7 Inside PV panels are strings of cells, paired string to drop to near zero. However, the average spot market GW in 2008, to 19.4 GW in 2010 and to and it is not uncommon to end up with Distributing intelligence down to the price for polysilicon is expected to In 2007, more than 90 percent of 37.6 GW in 2012. hundreds of PV cells connected in series panel level, it enables each panel to The result is that a PV system affected decline dramatically during the course polysilicon was supplied by only within these arrays. Similar to Christ- operate at its maximum power point by just 10 percent shade can cut its of 2009, falling to as little as $200 per seven companies: Hemlock, Wacker, The attached figure presents iSuppli’s mas lights, if one cell in this link fails to regardless of what is happening in the energy production in half. This phenom- kilogram. REC, Tokuyama, MEMC, Mitsubishi forecast of solar-grade polysilicon sup- produce current, the entire string drops string. This means PV arrays can now enon has to do with an extreme sensitiv- and Sumitomo. However, more than ply and demand. out. This is exactly what happens when be installed even if there is partial shad- ity of the solar architecture to mismatch- With new competitors entering the 60 other companies have announced partial shading or soiling occurs on PV ing, making way for green solar energy. es in the PV system. Clearly, after more polysilicon market, supply will outstrip plans to produce polysilicon by 2009, The decline in pricing and expected installations. As a remedy, modern panels Essentially, new micro-optimizer tech- than 30 years, solar energy manage- even aggregate demand starting in the resulting in many supply and demand oversupply of polysilicon will benefit PV have panel-integrated bypass diodes nology will truly enable solar to be more ment is due for a major overhaul. We beginning of 2010, causing prices to fall imbalances at the company-to-suppli- wafer makers that buy the raw material. that will attempt to re-route the current pervasive and efficient in real-world need smarter solar energy management further. Spot market pricing is expected er level. However, the pure solar wafer market around heavily impaired sections of the to propel this promising form of renew- conditions. www.national.com

12 Power Systems Design December 2008 www.powersystemsdesign.com 13 DESIGN TIPS

Power Supply Reliability Always measure the switch current In an article in June 2007, I wrote about the failure mechanisms of switching power supplies[1]. Almost always, at the heart of the failure, is the power FET. While it is not always the root cause of the failure, it rarely survives, and the failure can be quite dramatic. Most designers are careful to look at the voltage waveforms on the FET, and this is mentioned as a source of failure of a power supply in[1]. However, many power supplies that I see have no record of current measurement, and this means that engineers often miss impending problems in their designs. The current is not always convenient or easy to measure, but you should always make the effort to look at it. This article gives some tips on making current measurements.

By Dr. Ray Ridley, Ridley Engineering will become a less attractive business in supplies of polysilicon. In reality, pro- The solar wafer segment will undergo the future. ducing a wafer is not technically beyond consolidation sometime after 2012 after Current Sensing for an Offline C. (Conventional lab techniques use a the capability of either the polysilicon polysilicon prices collapse completely, Flyback Converter current probe at one of these points, but “The pure wafer business is a suppliers or the cell producer. Even- iSuppli predicts. Figure 1 shows a typical offline flyback these are often too large and their inclu- siren’s call,” Wicht observed. “The wafer tually, then, both polysilicon and cell converter with an integrated control- sion in the circuit can affect the wave- 0174-APEC2009 Ad 7.25 x 5.875 final.QXD 11/16/08 7:07 PM Page 1 www.isuppli.com business today is driven by profitability producers will try to drain all the profit ler. On the primary side, an RCD snub- forms. In some cases, this can even that results from the disposing of scarce out of this level of the supply chain.” ber is used to clamp the voltage peak cause failure of the power supply.) waveform on the power FET. Application notes often show this waveform under If you don’t have a suitably small all different conditions, including over- current probe, you can insert sensing current and shutdown mode. elements in the circuit to accurately measure the current. Figure 2 shows The RCD snubber provides a very ef- a current sense resistor at point A in fective clamp, and even in cases where the circuit, connected to the source TTHEHE PPREMIERREMIER there is severe overcurrent in the switch, of the FET. If your power supply 2009 the effect will not be shown in the volt- design does not already have this GLOBALGLOBAL EVENT EVENT age across the FET. It is crucial to look resistor in the schematic, this is NOT February 13–21, 2009 at the current in the FET directly to make ment point available in this schematic. a recommended approach. Integrated Washington, DC ININ POWER POWER sure the power supply design is rugged Current sensing is done internally in controllers can be adversely affected under all conditions. the power supply controller. In order to by the inclusion of a sense resistor ELECTRONICSTMTM measure the current, the circuit traces since the grounding of the controller ELECTRONICS There is no direct current measure- must be broken at either point A, B, or is changed. Visit the Apec 2009 web site for the latest information! www.apec-conf.orgwww.apec-conf.org

SPONSORED BY

Figure 1: Flyback converter with integrated controller. No Figure 2: Flyback converter with current sense resistor. current measurement point is immediately available.

14 Power Systems Design December 2008 www.powersystemsdesign.com 15 DESIGN TIPS DESIGN TIPS

operating in conventional PWM mode. Figure 5 shows a typi- cal current waveform for a well-behaved converter. There is an initial turn-on spike of current due to recovery of diodes, and stray capacitances. A subsequent ringing is quickly damped out, and the inductor current rise that follows is very linear.

The initial current spike presents problems when using the waveform for current-mode control, but filtering or leading- edge blanking can be used to solve this.

Figure 6 shows the same converter with an output inductor that is saturating abruptly. The slope of the current changes as 0/&."3,&5 the core saturates. Even though the power supply is in danger of failing with this condition, the impending problem cannot be Figure 3: Flyback converter with a current sense resistor Figure 4: Flyback converter with a current transformer from seen by just looking at the drain-source voltage waveform on from the voltage rail. the voltage rail. the power FET. The clamp voltage rises slightly, but you cannot 0/&#00, see the change in inductance directly. It is essential to monitor For a discrete controller and FET Figure 3 shows a current sense resis- Unlike an active current probe, the the switch current under all conditions to avoid saturation. design, the sense resistor can be used tor connected to the positive rail of the current transformer does not have any in the source, but bear in mind that the power supply. This point does not have delay in the sensing that must be com- Figure 7 shows another case of magnetics saturation. In this sensed current includes the gate drive any high-frequency excursions, and pensated for when assessing quantities instance, the converter is not overloaded, but the saturation 0/&#6: current, and this can be substantial if you isolate the power supply with a such as switching losses in the FET. is occurring during startup of the converter. The leading edge for large die FETs. With this setup, the transformer, you can put the ground This current sensing network is also the blanking period is too long, and the switch current is uncon- scope ground clip is connected to the of the scope on the positive rail, and preferred circuit for sensing the signals trolled during startup. This is a relatively common event in con- negative input rail, and this can present measure the inverted current signal to be used for feedback in higher power verter designs, and it must be avoided to prevent increased safety concerns for offline converters. across the resistor. This is a good and circuit, providing the required accuracy failure rates. For high power converters, it is advisable to have It should be done with extreme care. I reliable method of measuring the drain and speed. a secondary current limit which is active even during the con- always recommend isolating the power current, but it has the disadvantage that trol blanking period in order to prevent severe overcurrent that supply with a line-frequency transformer, the signal is very small, and you cannot Typical Converter Waveforms can lead to failure. and establishing a ground point on the simultaneously measure the voltage on The primary switch current for all negative rail to make this measurement. the drain of the FET. converters look very similar if they are Figure 8 shows a converter where the initial current ringing is never properly damped or controlled. The voltage waveforms The drain of the FET, point B, is also The current sense resistor method can in the circuit do not reveal this ringing. The ringing in the FET not a recommended point for measure- work well, and certainly is noninvasive in waveform presents serious problems in implementing current- ment. This node of the circuit has the the circuit with a small sized resistor. For mode control, and prevents accurate current limiting for the largest voltage excursions, and this will low currents, this is a valid approach. circuit. affect the accuracy of current sense Another way to measure the current resistors, current transformers, and cur- is with a current-transformer network, Other current waveform anomalies exist in PWM convert- rent probes. as shown in Figure 4. This circuit can ers, especially bridge or push-pull topologies. It is essential to provide measurement of small or large monitor all the currents to ensure there is no impending imbal- &.108&3*/((-0#"- currents, and will also provide a larger ance in drives. This can be a very sudden event in full-bridge, voltage signal. The current transformer half-bridge, or push-pull designs, and the consequences can *//07"5*0/ can be a standard component, or a severely degrade performance, or lead to failure. custom made transformer for reduced Announcing the newest member size. It is important to keep the loop of Figure 7: Current waveform with of the Power Systems Design family: transformer saturation during startup. Summary Power Systems Design North America. wire through the current transformer as It is not always easy to cut into a circuit to measure the For a full media kit, contact: small as possible since the inductance power switch currents, but this is an essential design step [email protected] Figure 5: Current waveform for well- created will increase the voltage stress to ensure that your converter is rugged under all conditions. behaved converter. on the power FET. Experiment with current-transformer sensing circuits, and you will quickly find this is a very useful approach for monitoring If you are using a current sense multiple currents in a circuit while maintaining isolation. You transformer network like this, it is often should always be careful that current sensing loops are kept a useful step to compare it to a resistor as small as possible so as not to introduce increased leakage sense method to make sure your current inductance that change circuit waveforms. sensing is working properly. Once the waveforms look good, the current trans- References former offers the advantage of provid- 1. “Why do Power supplies Fail”, Raymond B. Ridley, Power ing a fully isolated signal, allowing you Systems Design Europe article, July/August 2007, available on- to look at the current waveform at the line at http://www.powersystemsdesign.com/design_tips_ja07. Figure 6: Current waveform with hard same time as establishing a ground on Figure 8: Current waveform with pdf saturation with overload. the negative rail of the input converter. excessive ringing. www.ridleyengineering.com

16 Power Systems Design December 2008 www.powersystemsdesign.com 17

PSDE_Worldwide_Ad _half.indd 1 10/15/08 1:58:29 PM Four-Day Power Supply Agenda Monday Morning Lecture 8:30 - 12:00 Afternoon Laboratory 13:00 - 17:00 Design Workshop Power Stage Topologies Design of Flyback Inductor/Transformer Inductor Design Construction, Winding, Gapping Transformer Bordeaux, France at the Mercure Hotel z March 30 - April 2, 2009 Saturation Impedance and Leakage Measurement Core Loss In-Circuit Testing Learn first-hand from Dr.Ray Ridley, a leading power electronics industry Proximity Loss Snubber Design consultant and researcher.During his 28 years in the industry, he has taught Practical Design Procedures Full Power Testing advanced design to thousands of engineers worldwide.The world’s Efficiency Measurements leading engineering companies in aerospace, semiconductors and commercial applications send their engineers to the Workshop Tuesday Morning Lecture 8:30 - 12:00 Afternoon Laboratory 13:00 - 17:00 to take their designs to the next level. Transformer Design Design of Forward Inductor The Workshop focuses on theoretical and practical concepts Saturation Design of Forward Transformer with hands-on experience.Learn to design, build and Leakage Inductance Construction, Winding, Gapping Forward Mag. measure switching power supplies in our Planar Magnetics Impedance and Leakage Measurement state-of-the-art travelling laboratory. Proximity Loss In-Circuit Testing Multiple Output Cross-Regulation Snubber Design Study theory and design concepts each Winding Capacitance Full Power Testing and Efficiency Measurements morning, and build circuits and magnetics in the Practical Design Procedures afternoon. Learn how to use POWER 4-5-6, Gate Drive and Current-Sense Transformers the world’s most comprehensive design software and receive your own personalized copy for attending Wednesday Morning Lecture 8:30 - 12:00 Afternoon Laboratory 13:00 - 17:00 the workshop. Simulation of Power Supplies Measurement of Forward Control Characteristics Small-Signal Analysis for Voltage-Mode Control Output Impedance Measurement Tuition is €2500 and includes training, lab PWM Switch Model Control Loop Compensation notes, POWER 4-5-6 software and lunch. CCM and DCM Operation Loop Gain Measurement Reservations are now being accepted. Right-Half-Plane Zeros Stability Optimization Only 24 seats are available at each workshop. Loop Gain Criteria Step-Load Response Measurement Compensation Design Download a registration form at www.ridleyengineering.com Thursday Morning Lecture 8:00 - 11:00 Afternoon Laboratory 12:00 - 15:30 Current-Mode Control Measurement of Flyback with Current-Mode Current-Mode Circuit Implementation Compensating Ramp Addition Current-Mode Problems Control Loop Compensation Current-Mode Advantages Loop Gain Measurement Small-signal Analysis of Current-Mode Control Stability Optimization Subharmonic Oscillation Second-Stage Filter Design Current-Mode Feedback Design

WWW.RIDLEYENGINEERING.COM

SARL Ridley Engineering Europe ~ Chemin de la Poterne ~ Monpazier 24540 ~ FR ~ +33 (0)5 53 27 87 20 ~ Fax: +33 (0)5 67 69 97 28 Ridley Engineering UK Ltd. ~ 10 The Green ~ Bracknell, Berkshire RG12 7BG ~ UK ~ +44 (0)1344 482 493 ~ Fax: +44 (0)1344 204 632 Ridley Engineering, Inc. ~ 885 Woodstock Rd., Suite 430-382 ~ Roswell, GA 30075 ~ US ~ +1 770 640 9024 ~ Fax: +1 770 640 8714 Email: [email protected] ON THE ROAD ON THE ROAD

and AD9262 feature an on-chip PLL This provides designers the flexibility conversion, where the dual AD9262 and clock multiplier, decimation filters, and to offload signal processing functions to AD9267 can be used to support multiple sample rate converters and provide - an FPGA or other processor. wireless carriers and standards simulta- ible output data rates between 30 MSPS neously. The AD926x CTSD ADC family (mega-samples-per-second) and 160 Low Power Consumption is sampling now and will be available in On the Road volume production in April 2009. Com- MSPS. The 150-mW per channel to 350-mW Reported by Cliff Keys, Editor-in-Chief, PSDE per channel power consumption of the plementary ADI parts in the signal chain The AD9267, which features only the new CTSD converters is matched to a include the AD9520 clock generation high performance 640-MSPS modulator range of communications and industrial and distribution integrated circuit and the core and PLL clock multiplier, presents applications, including emerging ra- high performance ADL5382 I-Q demodu- Analog Devices the high speed data directly to the output. dio architectures, such as direct down lator. www.analog.com As ever, ADI brings something very special to the party. At electronica, the company unveiled many new products and I have selected the following as the pick of the best. Infineon Technologies At its press conference at the electronica trade fair, Infineon demonstrated its alignment with its key Inertial Sensors Motion Sensing customer segments and gave a powerful overview of the company’s commitment to this alignment. Here Industrial and Medical Instrumentation follows a report on the products presented. ADI expanded its award-winning iSen- The ADIS16405 features 0.05 de- sor™ intelligent sensor product family gree rate-sensor orthogonal-alignment- Intelligent Lamp Ballast Controller for Fluorescent Lamps with two new inertial sensors that make accuracy, which improves overall system it simple and affordable to implement accuracy and simplifies end-system Infineon launched its next-generation spanning from 0ms to 2500ms, which sophisticated motion and navigation design. The magnetometer sensors are lamp ballast controller that features allows lamp ballast designers to support control in a broader range of applica- calibrated and aligned to the inertial intelligent digital/mixed signal power a wide range of lamps, as well as highly tions, including medical instrumentation. sensor axis. The extensive calibration control. The new ICB2FL01G lamp bal- accurate timing and frequency control The ADIS16405 six-degrees-of-freedom and dynamic compensation results in last controller integrates Power Factor over a wide temperature range of -25°C Correction (PFC), lamp controller and Lamp ballast controller ICB2FL01G to +125°C. (6DoF) inertial measurement unit (IMU) an angular random walk of below 2.0 de- demo-board. combines high-performance, simplic- grees/√hr and temperature stability of 40 high-voltage half-bridge driver functions ity, and a tri-axis magnetometer sensor ppm/°C. All sensors are accessible over into a single, compact, surface-mounted lamps and emergency lighting. More and more emphasis is being for improved heading accuracy. The a standard SPI interface, which also al- package. Employing digital/mixed signal placed not only on the efficient produc- ADIS16300 four-degrees-of-freedom ogy™, the ADIS16405 complete inertial lows control of internal digital filtering. power control technologies, the product Digital / mixed signal power control tion of light, but also on its effective use. (4DoF) IMU is offered at an industry sensing system integrates a three-axis integrates all of the lamp start, run and enables stable, dependable ballast With this in mind, the ICB2FL01G has breakthrough price that is up to 10 times gyroscope, magnetometer, and acceler- The ADIS16300 and ADIS16405 are protection features required by current designs to be implemented with the been designed to be highly compatible less than other products in its class. ometer. The embedded magnetometer compatible with other iSensor multi- and future fluorescent lamp ballasts. Re- minimum of external components and at with dimmable lamp ballasts, offering provides accurate heading to comple- axis inertial sensors which include the liable and robust high-voltage isolation minimum system cost. Depending on the outstanding efficiency (up to 90 percent) Designed using ADI’s iMEMS® ment the product’s superior response ADIS16365, ADIS16364, ADIS16355, is achieved using Infineon’s proprietary application, more than 20 components, and THD (Total Harmonic Distortion) Motion Signal Processing Technol- and short-term stability. ADIS16354, and ADIS16350. Coreless Transformer Technology (CLT). including capacitors, diodes and resis- performance over a wide load range. CLT is by nature an intrinsically robust tors can be saved. Furthermore, the use Intelligent lamp fault detection and high-voltage isolation media and offers of this technology allows parameters restart control enable compliance with New Power Efficient Continuous-Time Sigma-Delta ADC Family excellent immunity from positive as well to be set utilizing only resistors, which Emergency Lighting requirements ac- as negative transients. avoids the issues with trimming and ag- cording to the European DIN VDE 0108 Analog Devices has unveiled the The new converters complement ing associated with the use of capacitors standard. industry’s lowest noise, widest band- Analog Devices’ data converter portfolio Typical applications for the ICB2FL01G in existing solutions. With few additional width family of continuous-time sigma- providing an exceptional combination product are electronic ballasts for com- external components the ICB2FL01G Availability and pricing delta (CTSD) analog-to-digital convert- of wide bandwidth and low noise. The pact fluorescent lamps, linear fluorescent supports multi-lamp designs controlling The ICB2FL01G lamp ballast con- ers (ADCs) today. The 16-bit, AD9261 highly integrated CTSD architecture T5 and T8 lamps, dimmable fluorescent up to four lamps as well as multi-power troller is sampling now. It comes in a and AD9262 CTSD converter, and the eliminates multiple discrete components ballast designs handling different power standard lead-free DSO package with 19 AD9267 CTSD modulator couple low at the system level, while simultaneously lamps. A key new feature of the second pins. Volume production is scheduled for noise and high dynamic range with a improving performance and simplifying generation ballast controller is the provi- January 2009. bandwidth of up to 10 MHz. product development. sion of special built-in test modes that al- low ballast manufacturers to dramatically A fully featured demo board is available The new ADC family achieves its Raised Performance Threshold shorten production test times, halving and the product is supported by compre- unique combination of speed, ac- The 16-bit single and dual AD926x the time for key tests such as End-of-Life hensive application documentation. curacy and bandwidth by incorporat- ADC family achieves industry leading detection and preheat operation modes. ing a breakthrough CTSD converter performance with an unprecedented Additional information on Infineon’s technology that is ideal for wireless combination of 86-dB dynamic range Further key features of Infineon’s ICB- new lamp ballast controller is available infrastructure, medical and other high- uncompromised data resolution and for an input signal bandwidth of up to Infineon’s proprietary Coreless Transformer 2FL01G lamp ballast controller include at: www.infineon.com/lighting performance equipment demanding wide bandwidth. 10MHz. The highly integrated AD9261 Technology (CLT). a wide programmable preheat time

20 Power Systems Design December 2008 www.powersystemsdesign.com 21 ON THE ROAD ON THE ROAD

and communications, automotive and ficer, Oleg Khaykin. Smallest ESD Protection Diode for RF Antennas appliances. “We fully anticipate the potential Infineon Technologies launched the 20kV contact discharge, exceeding by The pioneering GaN-based power impact of this new device technology world’s smallest transient voltage sup- far the industry standard IEC61000-4-2 device technology platform is the result of platform on the power conversion market pression (TVS) diode for the protection level 4 of 8kV. five years of research and development to be at least as large as the introduction of antennas in latest electronic equip- ® by IR based on the company’s propri- of the power HEXFET by IR some 30 ment. Applications include GPS, mobile The new antenna protection diode etary GaN-on-silicon epitaxial technology. years ago,” he added. TV, FM radio, and vehicles’ Remote ESD0P2RF-02LS is designed for appli- Keyless Entry (RKE) and Tire Pressure cations with signals swinging above and IR’s GaN-based power device tech- Prototypes of several new GaN-based Monitoring Systems (TPMS). The new below ground with a maximum working nology platform enables revolutionary product platforms were made available TVS antenna protection diode, the ESD- voltage of up to ±5.3V. Because of its advancements in power conversion solu- Oleg Khaykin, IR’s President and Chief to leading OEM customers at the Elec- 0P2RF-02LS, is only 0.62mm x 0.32mm bidirectional characteristics with sym- Executive Officer, unveils the new GaN tions. The portfolio of system solution tronica tradeshow which took place in in size and a mere 0.31mm in height. It metrical clamping voltage, orientation of wafer. (Note the handcuffs on the briefcase!). products and related intellectual property Munich, November 2008. is designed to protect the latest electron- World’s smallest transient voltage the device in the PCB is not an issue. suppression (TVS) diode. (IP) extends far beyond leading-edge discrete power devices by effectively ic communication and consumer devices Battery-powered mobile applications will deploying the company’s 60-year heri- Khaykin continued: “We believe that against electrostatic discharges (ESD) frontend systems or even directly into greatly benefit from this new subminia- tage in power conversion expertise in early adopters will be those market seg- and can reliably absorb electrostatic original component packages of filters ture TVS diode as it drains extremely a wide variety of applications including ments and applications that will take full discharges as high as 20kV. High linear- and ICs (e.g. System in Package, SiP). low leakage currents down to 1nA (at AC-DC power conversion, DC-DC power advantage of the revolutionary capability ity up to 6GHz together with market’s Especially valued for implementation in 5.3V) and therefore helps to extend bat- conversion, motor drives, lighting, high of transforming the value realization of lowest capacitance of 0.2pF for a TVS mobile phones and other thin portable tery duration. The ESD0P2RF-02LS is density audio and automotive systems. the key features of power density, power diode and low clamping voltages in a bi- devices, its ultra-low package height qualified according to the most stringent conversion efficiency and cost”. directional configuration are the perfect down to 0.31 mm can meet the most standards like the Automotive AECQ101 The high throughput, 150mm GaN- fit for sensitive RF antenna applications. stringent height requirements. standard. on-Si epitaxy, together with subsequent International Rectifier is already a Infineon is a technology leader in diodes device fabrication processes which are world leader in power management tech- and already launched the world’s small- Ultra-low capacitance Availability fully compatible with IR’s cost effective nology. Its analog- and mixed-signal est TVS diode for the protection of high- characteristics The ESD0P2RF-02LS diode is sched- silicon manufacturing facilities, offers ICs, advanced circuit devices, integrat- speed data lines in December 2007. With only 0.2 pF parasitic capacitance, uled to enter mass production by end customers a world-class, commercially ed power systems, and components the diode ESD0P2RFL-02LS offers op- of 2008 just as the ESD0P2RF-02LRH viable manufacturing platform for GaN- enable high-performance computing The TVS antenna protection diode ES- timum signal integrity at a maximum of diode in the larger TSLP-2 package based power devices. and reduce energy waste from motors, D0P2RF-02LS is designed in a tiny lead- protection against ESD without degrad- (1.0mm x 0.6mm x 0.31mm) for ap- the world’s single largest consumer less TSSLP package that measures only ing effects. That means that Infineon’s plications with less limitation on space “This leading-edge GaN-based tech- of electricity. Leading manufacturers of 0.62mm x 0.32mm (equivalent to the diode masters an extremely fast re- demand. Both TSSLP-2 and TSLP-2 nology platform and IP portfolio extends computers, energy-efficient appliances, 0201inch package with 0.024inch x 0.012 sponse time of less than 0.5 ns to effec- packages are fully compliant with RoHs IR’s leadership in power semiconductor lighting, automobiles, satellites, aircraft, inch in size). The miniature package, tively shunt the electrostatic discharge and halogen-free directives. devices and heralds a new era for power and defense systems rely on IR’s power- which is about 70 percent smaller than current away from the protected circuit conversion, in line with our core mission management benchmarks to power their today’s products with similar features, to a low and safe level, a characteristic Additional information on Infineon’s to help our customers save energy,” said next generation products. not only allows significant space saving that is of great value in very susceptible TVS diode product portfolio is available IR’s President and Chief Executive Of- www.irf.com on high density PCBs and great flexibility circuits in RF-antenna applications. The at: www.infineon.com/tvsdiodes but also it is specifically designed for the ESD0P2RF-02LS diode offers a multi- integration into complete modules and strike ESD absorption capability up to www.infineon.com Intersil I met with Dave Bell, Intersil’s President and CEO. I asked him directly what was new from Intersil for International Rectifier the power community. Dave gave me the answer. He then walked me through the company’s industry I was invited to attend International Rectifier’s unveiling of this new and certainly ground-breaking beating new power module, the ISL8201M. The company is rapidly expanding its areas of activity and is technology. The company, led by President and Chief Executive Officer, Oleg Khaykin, is leading the way well on track in achieving this through internal restructuring to integrate its acquisitions. The company is in attaining a supercharged figure of merit (FOM) for the new devices from this technology. cash rich, aggressive and hungry for expansion. A refreshingly powerful combination. Revolutionary New GaN-based Power Device Technology Industry Beating Power Conversion Module

Platform Intersil, universally known and respect- and cost. have been attracted to the device for its Proprietary GaN-on-silicon epitaxy and power device technology heralds new era for power conversion ed by designers in the arena of design high power density, high accuracy and and manufacture of high-performance This new DC/DC module has 4.5V high efficiency across a wide load range, International Rectifier announced the provide customers with improvements in ogy platforms to dramatically increase analogue semiconductors, announced to 20V input voltage range, 0.6V to 5V plus it can be easily probed with pins successful development of a revolution- key application-specific figures of merit performance and cut energy consump- at electronica, the development of the output range and 10A current capabil- easily accessible and not ‘buried’ under ary gallium nitride (GaN)-based power (FOM) of up to a factor of ten compared tion in end applications in a variety of ISL8201M, a highly integrated Power ity in a 15mm x 15mm x 3.5mm QFN the package. Inspection becomes ‘real device technology platform that can to state-of-the-art silicon-based technol- market segments such as computing Conversion Module that saves space package. Designers and manufacturers world’ in not having to rely on X-ray tech-

22 Power Systems Design December 2008 www.powersystemsdesign.com 23 ON THE ROAD ON THE ROAD

niques to examine hidden connections uted bus architecture based point of load under the package. applications. Also, an onboard input filter supports an ultra-low noise operation The ISL8201M, a high efficiency, low thus reducing EMI which can give a fast noise, highly integrated DC/DC power track to market. solution in a thermally enhanced QFN package, includes in the package the The ISL8201M achieves up to 93% PWM controller, MOSFET drivers, power efficiency and excellent thermal perfor- and inductor along with an mance due to the QFN package that optimized compensation circuit. is designed to offer an optimum heat transfer through the PCB. A large cop- It simplifies power supply design as per plate under the package allows the only input and output capacitors and ISL8201M to achieve a power density Brian took us through the ‘Cycles PowerWise utilizes Adaptive Voltage care (portability), Sensing & detection 3 a resistor are needed to implement a of approximately 200W/in , roughly four of Semiconductor Demand’ peaking Scaling (AVS) and combines external (security, health & surveillance), Per- complete power solution. This small form times that of conventional open-frame in 1974 with the mainframe computer power management with internal intel- sonal Mobile Devices, Electric vehicles / factor saves considerable board space modules thereby eliminating the need for and subsequent explosive growth of lectual property to dramatically lower battery management…the list is endless heat sinks. Other features include inter- the DRAM market. Some of us are long power consumption in digital CMOS in these power sensitive times. nal soft-start, auto-recovery overcurrent enough in the business to remember logic by actively monitoring conditions & protection, ENABLE pin option and pre- this! internal properties of the digital system SolarMagic™ biased output start-up capability. Dave Bell, Intersil’s President and CEO. to select the optimum operating voltage. The Solar market in particular is boom- Then along came the personal The system can save up to 64% over ing and Germany leads the way here. while the high integration reduces pro- The ISL8201M is housed into a tiny computer which peaked around 1984, traditional fixed voltage systems. SolarMagic is National’s answer to the curement and placement costs in various 15mm x 15mm x 3.5mm QFN package followed in 2000 with the proliferation practical problems encountered in the applications such as telecommunication, and is available imminently for sampling. of the internet and so-called ‘connected Unlike a mere brand though, Power- implementation of solar arrays. data communication, electronic data PCs’. Wise products are rigorously checked www.intersil.com processing, wireless network systems, against the company’s published metrics Ideally, the panel would be in full sun medical & instrumentation and distrib- Looking at the second chart, we can to help designers evaluate & compare the whole day delivering full output to see that the consumer driven cycle is analog components & subsystems the load. In practice, trees, leaves debris impacted by the cell phone, PDAs, video across a broad range of manufacturers. and ‘gratuitous deposits’ from birds can games, LCD TVs, digital cameras and cause shading and virtually shut down National Semiconductor consumer electronics, probably the big- According to Brian, the future of the system. Other known problems in- gest our industry has ever seen. But it PowerWise technologies lies in Analog- clude solar panel mismatch, panel aging, Brian L. Halla, Chairman of the Board and Chief Executive Officer addresses the press at electronica. doesn’t stop there. to-Information (A-to-I) where entire and panel failures. SolarMagic technol- processing chains move to the analog ogy is able to help overcome these types The only way is up! So what comes next? Almost as a domain delivering tremendous savings of problems by optimizing the energy sidebar, Brian explained how he gave in power due to ‘near instantaneous’ output of each individual panel in an ar- National’s chief, Brian Halla, pre- neering College Advisory boards. Brian one of his scientists at National the processing of analog signals directly into ray. sented to the assembled press at the tells us ‘just like it is’ –not a marketing challenge to use all the resources at his useful signals. electronica trade fair in Munich, Ger- pitch, but a realistic and therefore more disposal to predict what was coming, SolarMagic basically isolates the many. Capitalizing on National’s strength credible picture of where the industry is based on what the boom/bust cycles An example of this is National’s Far- shaded panel and so maximizes the out- in energy-efficient, high-performance and importantly, where it’s going. had brought in the past. Naturally, as a Field Noise Suppression (FFNS) where put of the other unshaded and produc- analog technology, Brian has sharp- scientist he used advanced mathemat- noise, traditionally the bane of mobile tive panels. Field trial results have been ened the company’s strategic focus to He called for a ‘Semiconductor Sea ics, simulation, the chaos theory and calls in public environments, is cancelled encouraging with SolarMagic technology serve major market segments including change’ arguing that governments do other ‘beyond my imagination’ theorems. using phase comparison at the micro- delivering 12% more energy over the en- personal mobile devices, communica- not care about our industry. Research The chart below shows this prediction phone, giving a clearer voice quality us- tire day. tions infrastructure, medical, automotive funding just doesn’t happen fast enough, curve, the red spot shows the uncomfort- ing 10% of the power that would be used and industrial applications as well as if at all. Our industry’s R&D dollars/eu- able position we’re in at the moment, but by a DSP solution. Brian expanded on the broad range of alternative energy. National’s leading- ros/pounds now target “Quality-of-Life” apparently, with good news on its way. offerings from National and concluded edge standard linear products include Megatrends. Analog continues to play The top PowerWise Markets include that with the opportunities open to our in- power management circuits, display an increasingly vital role as the enabler. PowerWise® Renewable energy, Distributed health dustry, even in these tough times, it is a drivers, audio and operational , Furthermore, Moore’s law doesn’t work National’s PowerWise product portfolio ‘Fabulous time for technology’ with low- interface products and data conversion here. Without low power technology, we consists of more than 300 products in power electronics (PowerWise), enabling solutions –products that enhance robust would, in Halla’s own words need ‘fans 25 product categories that are classi- green, portable, and brand new quality- sound, enable vibrant graphics, maxi- powered by Boeing’. Eloquently put! fied top performers in efficiency. It is, in of-life applications. Continued semi- mize battery life and power as well as simple terms, an umbrella brand that conductor R&D investments will now provide better portability. (SIA), the IEEE Noyce Award Commit- Low-power solutions will enable future gives a special badge for energy efficient drive this focus which for our industry – tee and the Silicon Valley Leadership solutions for all the new megatrends in products from National throughout their even given the current troubled times- He is extremely active in our industry; Group. He also serves on the University Energy, Healthcare, Safety and Personal product range including, Power Man- will mean a renewed vitalization of our on the board of , Inc., of California at Berkeley’s Engineering productivity such as Personal Mobile agement, Data Conversion, Operational technology. the Semiconductor Industry Association and the University of Nebraska Engi- Devices. Amplifiers, Interface and Audio. www.national.com

24 Power Systems Design December 2008 www.powersystemsdesign.com 25 ON THE ROAD ON THE ROAD

Sharp Microelectronics Texas Instruments Sharp introduced lighting for factories, offices and commercial spaces. The company’s next generation I met with Steve Anderson, Senior Vice President and worldwide manager of TI’s Power Management of lighting fixtures deliver high environmental performance combined with high energy efficiency and business unit and Uwe Mengelkamp who is responsible for definition, development, engineering and long product life. sales of DC/DC Converter products worldwide. Steve outlined the company’s new structure and gave me the clear message that the company is Dedicated to Energy Saving LED Lighting streamlined, well positioned, fit and ready to drive forward relentlessly in this highly competitive growing market. TI have taken top ranking in the power market share assessment according to Databeans and are releasing products in this sector at the rate of over 200 per year. Uwe ran me through the latest from TI, a report on which follows.

0.7-V Input Boost Converter Supports 5µA Operating Current

TI has introduced Smallest boost a 2-MHz DC/DC converter solution boost converter that in an SC-70 pack- Sharp LED down lights use only one fifth of the electricity of operates at 5µA of age Oblong and Square type LED lighting fixture. standard incandescent bulbs of equal brightness. quiescent current, The TPS61220, while maintaining a which comes in a Besides introducing the Zenigata optical design technology that reduces bies and entrance foyers of business high efficiency at light 6-pin, SC-70 pack- LED modules as illuminant component light absorption and boosts the percent- offices. load conditions. The age, can achieve a for lamp designers and system integra- age of light utilized by treating surfaces integrated circuit sup- total DC/DC converter tors, Sharp Corporation has developed to have high reflectivity. This technology LED lights, which have low energy ports an input voltage solution size of 6.4 x new series of LED lightings as finished provides efficient surface-emitting il- consumption compared to incandes- of 0.7V to 5.5V and 9mm with a height of products. The “oblong” type LED light- lumination minimizing variations in color cent lamps and fluorescent tubes, also an output voltage only 1mm. The small ing features a brightness equivalent to and light intensity overcoming draw- feature an outstanding environmental range of 1.8V to 5.5V, size and high perfor- standard fluorescent lamp fixtures that backs of LED-based lighting in the past. performance including being mercury- extending battery mance allow design- are currently the main lighting in facto- Coming in different color temperatures free and a long product life of 40,000 h life in low-power ers to implement the ries, offices and commercial spaces. The (4800K, 4900K, 5000K and 5600K) and which is about 10 years of operation at microcontroller-based device in any por- “downlight” type LED lighting systems also being available as “square” type an on-time of 10 hours a day. Besides designs, such as table, microcontroller- deliver a brightness equivalent to a stan- model the LED lightings are ideal for the resource saving effects this is reduc- single AA or coin-cell based application dard 150-watt incandescent light lamp. conference rooms and reception areas, ing maintenance costs particular on fac- alkaline applications. put, and discharge the system’s lithium- powered by A, AA or AAA batteries. Sharp introduced a total of 11 models, providing an even, uniform illumination tory floors and office buildings, whereas ion battery down to 2.5V. The device’s including four oblong, one square, and thanks to diffused surface-emitting light illuminating systems occasionally need The new TPS61220 boost converter, output voltage can be programmed by Leading power six downlight models. technology. be installed in hard to reach places. As which comes in a small SC-70 package, an external resistor divider, or is fixed management IC portfolio for large scale case all plants located within provides full battery capacity utilization internally on the chip. In addition, the MSP430 microcontrollers The “oblong” lights being introduced Further, the “downlight” line-up in- the new manufacturing complex now of a portable system, because of its converter can be disabled to minimize TI power management products sup- feature an elongated form factor cludes a model with light output of up under construction in Sakai City, Osaka ability to start up with a 0.7-V input volt- battery drain. port a wide range of microcontroller- resembling conventional fluorescent to 1,400 lumens which is equivalent Prefecture will adopt LED lightings man- age into a connected load. Based based designs, including those light fixtures equipped with twin 40-W to a conventional 150-watt incandes- ufactured by Sharp as the main lighting. on a hysteretic, off-time control MSP430-based applications that straight-tube fluorescent lamps. Due to cent bulb, the highest brightness in the This will represent the world's largest method, the device uses synchro- require ultra-low input voltage, low a luminaire efficacy of 74 lumens/watt, industry for LED Lightings. With a power collection of LED Lightings installed nous rectification to maintain more quiescent current boost conver- currently the highest in the industry for consumption of maximum 27.5 Watt the in buildings of this scope. Using this than 85 percent power efficiency sion or a low-power step-down LED lighting, the “oblong” Sharp LED Sharp LED down lights use only one achievement as a springboard, Sharp at the lowest possible operating configuration. In addition to the lighting delivers a light intensity of up fifth of the electricity of standard incan- will be working in the future to further current. This allows microcon- TPS61220, the TPS61200 boost to 4,000 lux directly underneath the descent bulb of equal brightness. The expand its LED lighting business into troller-based applications, such converter can support input volt- fixture at a distance of one meter. This series features lamps in three different factories, offices and commercial spaces as those that use TI’s new CC430 age levels as low as 0.3V and is equivalent to the brightness of twin color temperatures of 5200K, 5000K and around the globe. microcontroller and low-power RF lower, opening the door to energy 40-W straight-tube fluorescent lamps, 2800K. Besides the 150W equivalent www.sharpsme.com on a chip, to extend battery life harvesting designs. TI’s TPS780xx consuming about 25% more power lamps there are also 100W equivalent by maintaining efficient standby is the industry’s first 500-nA, dual- than the new LED lightings from Sharp. models available. These downlight types operation. output low-dropout regulators The outstanding light efficiency is also are suggested for use in commercial (LDOs) available in a 2mm x 2mm supported by the sophisticated lamp spaces such as shopping centers and The TPS61220 provides output SON package. design: Sharp developed a proprietary department stores, as well as hotel lob- current up to 50mA at a 5-V out-

26 Power Systems Design December 2008 www.powersystemsdesign.com 27 ON THE ROAD ON THE ROAD

asset for our international business. Itzehoe for the manufacture of standard shay ESTA has developed and supplied 60V SWIFTTM DC/DC Converter Eco-modeTM Technology Proximity to our customers and location 200-mm MOSFETs). the DC voltage filter capacitors for the loyalty, both in the USA and Germany, HVDC between the Chinese provinces Maximizes Light-Load Efficiency play a major role. Thus, jobs are shifted Vishay’s Research and Develop- of Yunnan and Guangdong and has built if necessary, but processes remain at the associated capacitor banks. A first Expanding on the company’s popular 2.5MHz reduces the size of the output ment Expertise Trendsetting in the same location.” During economically in this project was the high transmis- integrated SWIFT™ family of DC/DC inductors to save board space. The Industrial Electronics/Energy difficult times, market diversification sion power capacity of 5,000MW, with converters, TI introduced a new 60-V TPS54160’s frequency fold-back and Saving and Automotive Projects helps carry the Company and stands for In 2006, income from products less a voltage of ±800kV and a line length input, 1.5-A output step-down switcher thermal shutdown features allow the Company security. Vishay also stresses than 5 years old was, on average, of 1400km, while the previous limit was with integrated FET that achieves signifi- converter to protect itself during an over- that no single OEM customer accounts 26.4% (semiconductors: 35.6% and set at a transmission voltage of 600kV. cant energy savings in light-load efficien- load condition. for more than 5 percent of its turnover. passive components: 15.3%). By 2010, The project, under the leadership of cy. The wide-input converter helps save these figures are set to increase to 36% Siemens, will be completed by 2010 and up to 25 percent of board space com- The TPS54160 also has an inte- (semiconductors: 46% and passive another project is currently underway pared to competitive wide-input voltage grated track pin that simplifies various Acquisition strategy of profitable components: 22.3%) which, if expressed in India. A further new application is for solutions and eases design in industrial sequencing schemes and a clock pin specialty products Despite the current downturn, Vishay in figures, represents a rise from $681 offshore wind parks, where energy is fed and automotive applications. that reduces noise by synchronizing its has pursued a continuous acquisition million to $1.08 billion. to the mainland across cables. These switching frequency to an external clock. strategy, as Dr. Felix Zandman, Execu- also require large quantities of power The TPS54160 non-synchronous buck able to achieve a low 116-uA operating TI’s SWIFT DC/DC converters serve tive Chairman of the Board and Chief Vishay’s R&D investment, which leads capacitors. The latest project is the EON converter operates from a 3.5-V to 60-V current and 1.3-uA shutdown current, a broad range of applications, such Technical and Business Development to involvement in many leading applica- offshore project in northern Germany. input voltage range providing designers resulting in longer system run-times and as telecom, computing, industrial and Officer of Vishay said: “We will continue tions and projects, is a key factor in the flexibility in applications with input tran- a more efficient power system design. consumer point of load applications with our acquisitions and drive organic growth company’s image and growth. Vishay ESTA’s cooperation with sient protection up to 65-V. By leverag- input voltage ranges as wide as 60V and TM by focused R&D activities.” CERN (the European organization for ing TI’s innovative Eco-mode light-load In addition, the converter’s high output currents as high as 14A. particle physics) is of particular interest switching technique, the converter is switching frequency range of 300 kHz to www.ti.com Industrial Electronics/Energy Capital investment in the current finan- Saving in the progress of science. Vishay ESTA cial year is at a high level, with some With an average growth of 15.7% supplied CERN with 8 units of 18-kV 150 to 160 million US dollars. This is an per annum (from 2003 to 2008), Vishay condenser filter banks for the SPS (super important milestone in the completion ESTA has a unique position in industrial proton synchrotron) in the quest for the of Vishay’s specialty products offering, automation. Vishay ESTA is the only Higgs particle. These components have Vishay Intertechnology, Inc., one of the world’s largest manufacturers of discrete semiconductors which finds itself momentarily in a dif- company worldwide to offer a complete an installed power of 247 Mvar and con- ficult profitable situation. For example, range of power capacitors, thereby oc- sist of 420 capacitors, with a total order and passive electronic components, completed the third quarter of 2008 with net revenues of 739 the acquisition of KEMET Corporation’s cupying 15% of the European power value of approximately 400,000 Euro. million US dollars. The overview from the company’s press conference at electronica follows. wet tantalum capacitor line in September capacitor market. In Europe, the market The capacitor filter banks are used for marked a further step in the extension of grows annually by approximately 5% both reactive power compensation and Vishay’s specialty capacitor product port- and in energy content over 25%. In ad- power grid voltage stabilization for the Well Equipped for a Troubled Market folio, which is used in military, aerospace dition, the market also demands smaller SPS particle accelerator. Commenting on the current business and medical applications. and specific, optimally adapted capaci- climate, Dr. Gerald Paul, CEO of Vishay, tors and capacitor designs. This is where ESTA power capacitors can also be stated, “Overall, the last quarter for Dr. Gerald Paul continues: “Any take- Vishay ESTA scores with its customized found worldwide in the metro trains of Vishay and the entire industry has been over offers new synergies and opportu- development and production of capaci- many large cities (including , difficult. Sales and profits have remained nities for growth. It supports our basic tors. The capacitors, manufactured in , , Delhi, Bombay). lower than expected. The low order principle of being a “one-stop-shop,” the Czech Republic, are designed to ESTA capacitors were selected for a intake in October points to a further because we offer developers the widest meet increasing demands for longer life, recent project in China aimed at the economic slowdown. Nevertheless, we choice of discrete semiconductors and reliability, electrical characteristics (high construction of freight locomotives - with achieved 0.18US dollars net earnings passive components. By creating new acceptable current loads of up to 800 an output of 9600 KW (13000 HP), these per share, and 55 million US dollars products, we can address new markets A for each unit, small self-inductance are the 1500 most powerful locomotives from continuing business activities, and and drive our vertical growth.” <40nH), lower losses and smaller in the world. generated a free cash flow of 89 million weight. Development and testing, as US dollars. All acquisitions underscore Vishay’s well as MTBF tests, all take place at the Automotive stable position as a safe and local Landshut, Germany headquarters. The automotive industry, which has In the meantime, the automotive in- supplier of high-quality products, the highest demands in technology, Dr. Gerald Paul, CEO. dustry in Europe has also suffered from Dr. Felix Zandman, Executive Chairman of regardless of economically turbulent Projects leading the way: quality and reliability, is clearly lead- the economic slowdown, as have mobile to maintain its free cash flow. This also the Board and Chief Technical and Busi- times. Vishay’s share of new products Energy transportation, power ing the way. Vishay’s expertise in the ness Development Officer. telephones, computers and consumer applies to worst-case scenarios.” introduced to the market continues to quality (current and network automotive market is confirmed by its goods, which remain below expectations. and business market leader. Despite increase and its R&D program is on quality), traffic control turnover of between 16 and 20% of total Conversely, industrial automation is rela- Diversification in terms of sales losses, the last quarter’s results target. The Company is still committed to High-voltage direct current (HVDC) revenues. Vishay optimizes the power tively stable, as is military/aerospace. its products, geography, markets – confirm the Company’s conservative the development of its production sites transfers are required for the transporta- loss of all the components required in a However, orders from global distribu- beneficial in times of crisis financial policy, which allows it to remain in Germany. In recent years, Vishay has tion of electricity from large water- and converter (buck or boost) including the tors are decreasing rapidly. Should the From the start, Vishay has been a fi- free of debt. Diversification is an impor- invested large sums in the development coal-fired power stations to far removed storage choke, the MOSFET switch and recession become deeper and longer, nancially strong and innovative company, tant factor in this, as Dr. Paul stresses: and optimization of its German capacity large cities, resulting in high demand for power Schottky diode (rectification) as Vishay will take all necessary measures and has established itself as a technical “Our geographical distribution is an (e.g., conversion of wafer production in DC and AC high-voltage capacitors. Vi- well as the power capacitor.

28 Power Systems Design December 2008 www.powersystemsdesign.com 29 ON THE ROAD

The new storage choke IHLP®-1616, power savings is the new START-STOP and car manufacturers increasingly with its patented IHLP® technology (In- function: It switches off the combustion require that they exhibit electromagnetic ductor High Current Low Profile), allows engine on short stops in order to reduce immunity to external interference. The Energy-Efficiency: for very high saturation current levels in fuel consumption and CO2 emissions. power filter components (l-, PI-, LC-filter) comparatively small dimensions. Vishay Without the required powerful DC/DC must also be designed to keep line volt- can also adjust certain coil parameters, converters that overcome the battery age drop to a minimum (battery clamp including the relative permeability µre, the voltage interruption phase, this proce- or ignition clamp). Vishay leads the way Walking the Talk winding geometry and the DC resistance dure would cause serious problems to with its new series of filter chokes (IHTH) (DCR). the on-board voltage supply and thus that feature a very low DC resistance of I talked with Andrea Mirenda, VP of Marketing, Fairchild Semiconductor, about to the operation of devices which are 0.5mΩ at 2.2 µH and a rated current of the way that some companies are now struggling to get themselves in better shape for the future ‘leaner The newest TrenchFET® MOSFETs required, even if the engine is switched 50A. from Vishay Siliconix (qualified to off, or on restarting. Today, the START- and greener’ way they must now do business. Fairchild, with a proven track record in this arena, AEC-Q101) allow junction temperatures STOP function already generates a sav- Losses in control electronics are a was a good place to put my question. Here is what she told me. of up to +175°C and are the first compo- ing of up to 8 percent of the fuel cause for higher fuel consumption and nents of this type in small housings that consumption. In combination with brak- thus higher CO2 production. The number oday’s industry buzz words are have a far reaching impact on consum- are suitable for automotive applications. ing energy recovery this can even be up of discrete components in an electronic green and energy-efficiency. It is ers who have power supplies for their Due to their higher cell densities, they to 12%. Highly efficient inverters/regula- control unit (ECU) is usually, depend- Tencouraging to see our industry household electronics and on residential have an advantage over planar technolo- tors will be needed, as well as an addi- ing upon application, from 50 to 2500 step up to the challenge of innovation electricity consumption. Lighting ap- gy, and offer very low switching losses at tional battery sensor (high Power Metal devices. Each device, through which a and focus on contributions that address plications consume 22 percent of the ® high frequencies (>100kHz). The first au- Strip shunt, 100 µOhms, 36 W) for the current flows, produces energy dissipa- the significant environmental issues we electrical energy generated worldwide. tomotive Trenchsky™ (Trench Schottky) monitoring of both charging and load tion. Vishay has specifically developed are facing. Although there are many as- Transitioning from a standard incandes- also show significantly lower currents. components with high component pects of participation, it is important that cent bulb to a compact fluorescent lamp power losses in comparison to standard density and low energy dissipation — for we welcome all to this bandwagon to (CFL), LFL, HID, or LED, can recoup Schottky diodes. The newest available Trendsetting vehicles (hybrid, electric, example, resistor networks and arrays in share best practices and challenge one as much as 75 percent energy sav- product is the 200-V/30-A double-high- fuel cell) require new technologies (e.g., diverse technologies (thick and thin film) another to invent the next power-saving ings. Package options that reduce size ® voltage TMBS Trench Schottky rectifier, SiC) and high-voltage components. The or combinations of R/C components. As product. It is important that this topic and weight but match the performance which is an economical alternative to fuel savings and emission reductions these arrays save copper circuits, they is not solely a marketing campaign; it requirements also contribute to the op- synchronous rectifier solutions. required for today and the future can be reduce line losses and thus the building needs to be ingrained in a business’ tions available for energy savings. attained with various technologies, but area of a controller, which contributes, consciousness and an integral aspect of Trendsetting projects: all of these rely on electronics (hardware) again, to the weight reduction of a mod- a company’s corporate responsibility. To have a significant impact, environ- START-STOP function, brake by in connection with associated software. ern automobile. mental awareness must extend to the www.vishay.com wire, sensor technology The electrical controllers and sensors in Semiconductor suppliers are the key corporate and individual employee level. A concrete project for achieving the vehicle are of particular importance drivers of innovation in the world of elec- It needs to be ingrained in our DNA to tronics, but they also are instrumental in focus on energy-reduction and ways developing energy-efficient technology to conserve resources. IT departments and “greening” their IT, manufacturing migrating to environmentally friendly need to initiate server consolidation and employee practices to make them materials are critical activities for practices that can result in tremendous more environmentally friendly. sustainable and economic production. energy-savings. This includes reducing 0/&."3,&5 Supply chain improvements such as re- the number of servers, choosing energy- Companies need to become both ducing transportation requirements will efficient servers and servers that have a entrepreneurs in developing innovative conserve energy and have the added smaller footprint. Semiconductor suppli- technology, and ecopreneurs in creating benefit of shorter cycle times. Finally, ers need to monitor and record the rates energy-efficient technologies; limiting the every employee’s willingness to assume of water and energy usage and solid 0/&#00, use of materials that are environmentally the mantle of recycling/reuse, conser- and hazardous waste generation. We &.108&3*/((-0#"- unfriendly; and generating internal busi- vation and elimination of waste has the must encourage individual employees to ness practices that conserve resources. promise of profound positive impact on be aware of their pivotal role in conserv- *//07"5*0/ efficient use of resources in both the ing resources. This can be as simple Minimizing environmental impact has work place and at home. as printing only what you need or car $IJOB &VSPQF /PSUI"OFSJDB 0/&#6: many facets. A fundamental oppor- pooling to work with someone in your In print and online. tunity for improvement is developing Technological advancements in IC neighborhood. All of us have the oppor- For Power Electronic Engineers Only. and incorporating technological ad- design and advanced packaging are tunity to be environmental stewards. For a full media kit, contact: vancements to reduce energy waste in instrumental in reducing wasted energy. [email protected] popular applications. Addressing energy In motor applications, we are witness- Designers and system architects in consumption vs. energy requirements ing the shift from single-phase AC mo- semiconductor companies cannot just in sleep mode, standby mode and ac- tors to variable speed motors, resulting simply create energy-efficient products, tive mode provides a perspective to the in a 40 percent energy savings. Power but must also actively contribute on problem that helps define the solution. supplies waste a tremendous amount of behalf of their company to the ways that Another opportunity for improvement energy in standby mode. By developing their environmental stewardship can is manufacturing practices. Recycling, power supplies that increase efficiency make a difference in the broader sense. conserving water and energy and and reduce standby power, this will www.fairchildsemi.com

www.powersystemsdesign.com 31 and in the future, are dependent on opment –education courses taught by The place to be February 15-19 is in power electronics as an enabler. top experts in the industry, plus the time Washington, DC, at the beautiful Mar- to network, compare experience, ideas riott Wardman Park Hotel. APEC 2009, Washington DC, APEC is the best technical conference and opportunities with other profession- www.apec-conf.org February 15-19th in the industry with professional devel- als in the industry. Where real engineering happens Power Sensitivity in Design The yearly IEEE Applied Power Electronics Conference APEC 2009 (www.apec-conf.org) will be here Makes Networking Green soon and with it, the gathering of the best and brightest in power electronics which takes place this time around in Washington, DC February 15-19 2009. This, the 24th consecutive year for the conference, will I talked with Melvyn Wray, Senior Vice President of Product Marketing EMEA, of Allied Telesis who highlight applications from portable power in low power battery applications to UPS, Inverter, Motor make Gigabit Ethernet switches for the worldwide networking industry. This is a vast power consuming Drives, vehicle electronics and everything in-between. industry and one gaining high visibility now in the quest to maximize efficiency and reduce losses.

ncreasingly, the efficiency of power conversion, battery chargers, induction n keeping with the com- allows length of cables to be electronics for the generation, conver- heating and myriad other applications. pany’s commitment to determined (VCT technology), Ision delivery and utilization of energy Ienvironmentally friendly and to only inject the required in practical applications is of paramount Several ‘mega trends’ are driv- processes and products, the amount of power needed to economic and environmental impor- ing increased intelligence in systems AT-9000/28 is the first of its power the cable. Obviously tance. We are fortunate that the APEC including the impact of internet- con- new green range of products cables have resistance and conference is again designed for engi- nected systems which incorporate not designed to reduce power impedance which both con- neers by engineers. The APEC board only power electronics but networked consumption, minimize haz- sume power. On shorter cable is consistent in its efforts to ensure all intelligent power electronics able to ardous waste and even reduce runs the switch consumes sig- technical content is peer-reviewed and communicate and manage on a huge environmental noise pollution. nificantly less power ~9% on all new material, representing state-of- scale. For example, home appliances tests the company has carried the-art, practical and technical content which can communicate to a smart grid The AT-9000/28 is a 28 port out on their products. of the highest quality. to the utility for demand planning via Gigabit managed switch with a network enabled power meter at the 24 port 10/100/1000Mbps Allied Telesis AT-9000 Block Diagram. When RJ45 not connected, APEC’s exhibitors represent the top home. Green and Sustainable practices fixed configuration and 4 -ad or the remote device is pow- global suppliers to power electronics being mandated for energy conserva- ditional 100/1000Mbps SFP ports in A highly efficient internal power ered off, the switch can go into an over- designers involved in test and measure- tion and reduction of emissions as a combination with 10/100/1000T ports. adapter was chosen to provide minimal night mode, where the PHY is basically ment, components, services, software business mandate, is another industry power loss, but without escalating the put into a sleep mode. Every millisecond and systems. APEC has become a trend. As one of a series of high performance costs making the switch non-viable in or so, it is brought back to life to check ‘pacing’ event annually – in other words, Gigabit Ethernet switches from Allied the marketplace. Power efficiency is if there is some equipment connected, organizations time their product releases Smart power electronics are becom- Telesis, the AT-9000/28 provides high 83% representing best in class perfor- if not it is put back to sleep. Again, if on and new technology announcements to Kevin Parmenter, General Chair ing pervasive in medical electronics performance Layer 2 switching at an mance measured from AC in to DC out. time is 10% and sleep time is 90%, then align with the APEC conference dates. APEC 2009 -IEEE Applied Power Elec- applications from diagnostics to home affordable fixed configuration platform. significant power savings are made. Importantly, the press, financial and in- tronics Conference and Exposition healthcare and tele-health applica- The switch brings enterprise features to With the high performance, low power dustry analysts will be there as well as a Promoting standards and incentives tions. Consumers are demanding safer, a more affordable level while supporting design there was no longer the need for Allied’s simple yet effective ECO- vast range of prospects and customers. for technologies which reduce losses, healthier products and enhancement in the changing needs of the SMB market the ‘traditional’ main cooling fan (only a Switch - turns of unwanted LEDs. A increase efficiency and effectiveness in quality of life, increased convenience space to improve the delivery of con- very small CPU fan for the main Broad- typical switch has at least 2 LEDS per The conference will be ‘greener’ this power electronics applications. and quality experiences. These prod- verged data. Support for jumbo Ethernet com chipset). port, so in the case of the AT-9000/28, year. The APEC board is instituting sus- ucts need built in maintenance, repair frames enables higher throughput of turning off the LEDs saves 0.6W, and a tainable practices in collaboration with It is clear that the rising cost of energy and diagnostics – fault monitoring via time sensitive data. The traditionally utilized fans consume couple of degrees of temperature inside its conference partners to greatly reduce has dramatically increased awareness the network. The markets range from in- significant power, and also greatly in- the unit. this waste and reduce environmental of the new role of power electronics as dustrial, consumer, residential, commer- The company opted for an advanced crease noise. The issue is compounded impact. the single most important enabling tech- cial, government, for energy generation chipset with the latest Broadcom Sili- when whole banks of these switches are This method of ‘chipping away’ at the nology for the future well being of the energy storage and energy management con, BCM56214. This represents 10th installed, both in terms of heat and noise power consumption by the use of high Appropriately, as the conference is environment. We are fortunate that we in all kinds of systems including trans- Generation Switch on a Chip silicon pollution. We have all heard the reports quality silicon together with the creativ- in Washington, DC, the intention of the are in the right business and discipline portation, communications/ computing with very high density. Lower power = of huge air conditioning plants being run ity that makes good design engineering APEC conference is to promote aware- with the right technologies at the right systems. 7.6W. At the time of design, this was to keep the networking and processing worthwhile, is certainly the way forward ness of opportunities available in power time. Power electronics is an essential the lowest power chipset on the market equipment running in datacenters. to reducing the future power overhead electronics to make a global impact part of optimizing diverse applications The critical systems which will make and chosen for this new ‘green’ product of our vital networking systems. on important issues facing our world: such as lighting, motor control, power a difference in all these areas, both now development. Use of the latest PHY technology www.alliedtelesis.com

32 Power Systems Design November 2008 www.powersystemsdesign.com 33 COVER STORY COVER STORY

Speed and Precision in Gate Drives Figure4: Circuit representation of a typical gate loop (simplified).

custom integration of almost all gate High-power gate driver controls MOSFET driver functions into ICs leads to an enormous 80% reduction in component count compared to conventional solu- switches up to 500kHz Figure2: Output power vs. switching frequency. tions.

Modern power semiconductors allow switching schemes that would have been unthinkable even ten Figure 2 shows the output power ver- sus the switching frequency of the gate TM years ago. Conventional MOSFETs, COOLMOS devices and prospective compound semiconductor driver. The gate resistance is 1.0W for switches are constantly pushing the limits of power density and switching frequency. Only a dedicated both the turn-on and turn-off resistors. The maximum switching frequency is gate driver allows the full potential of today’s most advanced power switches to be exploited. limited by the self-heating of the driver under natural convection cooling. In By Sascha Pawel and Jan Thalheim, CT-Concept Technologie AG, Switzerland MOS mode, the driver allows extremely fast switching of up to 500kHz for an output voltage swing of 10V and 370kHz t is common wisdom that prediction or IGBTs: their voltage drop under load as converters for solar panels, auxiliary for one of 15V. The output curve in IGBT is difficult, especially about the future. is determined solely by their turn-on drives in industry and traction, mains- mode is shown for comparison. Dedi- At the moment, however, it seems as resistance R . In contrast, IGBTs operated chargers and many more. I DS_on cated thermal balancing trades a part if a multitude of long-cherished dreams require a minimum forward voltage drop of the 20W in IGBT mode off against are on the point of coming true for de- of several hundred millivolts in order High-frequency systems are another a higher switching frequency in MOS signers of power conversion systems. to forward-bias the internal diode. This typical application area for MOS-gated mode. There is great public interest in renew- voltage offset sets an efficiency limit . The switching losses of bi- able energy, the concepts of zero emis- under light load conditions, when only polar devices increase sharply with op- Gate Control sion vehicles and hybrid cars are finally a small current is flowing through the erating frequency, because the electron- Fast switching in the hundreds of kilo- gaining momentum and a whole wave power switch. Whenever the mission hole plasma has to be removed and built hertz range not only requires high drive of small improvements to the ecologic profile of the power application includes up in every switching cycle. MOSFETs power and maximum frequency but footprint of our lifestyle constantly feeds light-load operation, MOS devices are do not exhibit this high-frequency limita- also tight control over crucial param- people’s awareness of formerly elusive often the best choice. This opens up tion and can be operated up to several eters such as the driver’s delay time and Figure3: Measurement of driver delay and delay time jitter. issues such as sustainability and ef- a broad range of target systems such hundred kilohertz and beyond. The the associated jitter. A fast driver with ficiency. All this leverages main benefits of elevated field strength of silicon. Typical voltage High-Frequency Gate Driver a short delay introduces significantly the role of power elec- switching frequency are: ratings for conventional power MOS- No matter which device type is used less phase lag into the power system’s tronics, since electricity smaller systems that FETs are in the range of 20V to 300V. in a given application, the main current control loop. Less phase lag is of great is the most valuable and occupy less compart- Charge compensation devices, such as and thus the power flux is determined importance for maintaining the stabil- flexible form of energy. ment volume, higher COOLMOSTM, can break this barrier with by the charging and discharging pro- ity of the control loop, thus allowing With that in mind, efficien- power density, a smooth blocking voltages of up to 600V and cess of the device’s gate capacitance. the benefits of fast switching to be fully cy is probably the single output current waveform, even 900V. The required drive power is supplied by exploited. Fig. 3 shows the measure- most important criterion and satisfying functional a high-performance gate driver such as ment of driver delay and delay time jitter. for judging the quality of requirements such as the An alternative approach has been the 1SC2060P shown in Fig. 1. A dedi- The graph reveals ultra-fast switching future energy systems, penetration depth and followed for more than two decades. If cated MOSFET mode is implemented at a typical 74ns delay and enormous because no user will ac- power coupling in induc- the properties of silicon are limiting, why in the 1SC2060P. It allows the optimum reproducibility with a standard devia- cept wasting precious and tive heating systems. not use another material? SiC, GaN and output voltage swing Vdd across the tion of less than 185ps. The total delay expensive energy. a great variety of other compound semi- power switch to be chosen freely. Any variation is virtually negligible with a Of course there is a conductors offer superior features such value between 10V and 20V can be maximum of ±1ns over 285,000 acquisi- MOS Power Switches fundamental drawback to as breakdown field strength and thermal utilized, whereas the separate IGBT tions. This combination of power and MOS switches hold MOS switches as well - conductivity. The time might finally have mode incorporates switching up to precision makes the 1SC2060P the first a decisive low-voltage their blocking capability come for these new power devices after 25V (–10V / +15V). The driver shown in choice for highly optimized systems, advantage over bipolar Figure1: Gate driver core 1SC2060P with planar transformers (di- is limited by the com- a long maturing process and constant Fig. 1 is based on CONCEPT’s recently where tight control over timing margins devices such as GTOs mensions 74mm x 44mm x 6.5mm). paratively low breakdown cost-performance improvements. introduced SCALE-2 ASIC chipset. Full is mandatory.

34 Power Systems Design December 2008 www.powersystemsdesign.com 35 COVER STORY COVER STORY

At very high frequency switching, the In real-life applications, the model acteristics in the field. Figure 7 shows influence of parasitic circuit elements from Fig. 4 is too simplistic to model the (4) the results of accelerated life testing has to be considered to obtain optimum circuit behavior. The maximum stable with slow thermal cycles. The partial performance in the gate drive loop. peak current is typically lower than the Equation (4) is very simple but still discharge extinction voltage is the most Figure 4 illustrates a simplified gate loop limit of equation (3) and is often close to much more precise than the widespread sensitive and dependable criterion of consisting of a driver module, the turn- two thirds of Vdd/Rg. Figure 5 shows an approach of obtaining the required insulation performance. No degradation on and turn-off gate resistors, parasitic exemplary turn-on transition from 0V to drive power from the datasheet value is visible after as many as 2,600 cycles. inductances of the gate resistors, the 15V with a 1.0W gate resistor where the of the input capacitance. The curve of This accumulated stress is equivalent parasitic inductance of the power switch peak current only reaches 10A instead MOS gate charge versus input voltage to more than 20 years under real-life gate and an effective load capaci- of the theoretical maximum of 15A. Thus is highly non-linear. As a result, only the application conditions. Exorbitantly tor. This configuration is a well-known the 60A current rating of the 1SC2060P actual gate charge value Qg can yield a harsh thermal shock cycles between – standard RLC resonance circuit. For leaves ample reserve for even the larg- correct prediction about the drive power 55°C and +150°C have been applied to both the turn-on and turn-off transition, est MOSFET power switches. needed in the given application. probe even further. Again, virtually no the elements can be concentrated into change in insulation characteristics can an effective gate resistance Rg, the load Figure 5 also shows the acquisition of Planar Transformer HV Technology Figure7: Insulation stability versus slow thermal cycling. be seen, as evidenced in Fig. 8. The capacitance Cg and the sum of all effec- the gate charge Qg per switching transi- The 1SC2060P driver core comes with tight 3-sigma boundaries of the partial tive parasitic inductances Lg. The gate tion. Qg is equivalent to the area under an ultra-flat form factor and measures discharge extinction voltage shown in drive current i(t) is then governed by the the gate current curve. The required only 6.5mm in height. This is achieved Fig. 8 highlight the stable uniformity of differential equation (1). drive power can easily be calculated by using newly developed planar trans- the planar insulation. from equation (4). former technology. A schematic cross Numerous additional tests have been (1) performed to assess the aging behavior of the planar transformers. Mechani- Solving for i(t) yields the time-de- cal shock tests up to 2000m/s2 showed pendent drive current. Even in the sim- absolutely no impact on mechanical plest case with constant parameters or electrical parameters. The effect of Lg, Rg, and Cg, the solution shows humidity has been investigated by tem- two distinct characteristics depending perature, humidity and bias testing at on the ratio of the damping resistance 85°C, 85% RH and a constant DC bias Rg to Lg and Cg. If Rg is too low, the of 1500V. No failures occurred after current waveform will take the form of more than 1000 hours in this truly ex- a damped harmonic oscillation. This treme climate. Figure8: Highly accelerated thermal shock testing (-55°C / +150°C to IEC case is undesirable in a gate control 60068-2-14 Na). loop because it leads to a gradual loss Summary of controllability and because of seri- section is shown in Fig. 6, as already their lifetime. It is therefore important to A dedicated high-frequency gate ous EMC problems. If Rg is very high, reported in PSDE of July 2008. In con- make sure that the reliability figures of driver is needed to fully exploit the slow settling towards the final value trast to common planar designs in low- every component in the power system capabilities of state-of-the-art MOS will occur without any oscillations. The voltage systems, there is no interleaving are much higher than expected from the power devices. The 1SC2060P driver boundary between these two charac- of the primary and secondary windings application, because the failure prob- core has been specifically designed for teristics is given by equation (2) in our in the layer stack. A dedicated high-volt- abilities of the individual components high-power and ultra-fast switching to model. age insulation layer is placed between add up in the system. satisfy this need. It employs SCALE-2 the primary and secondary windings chipset technology and newly devel- (2) with no crossings or vias penetrating it. One of the greatest contributors to oped planar transformers for unrivalled The specific effect of this construction is the failure rate is the number of com- timing precision, high power density Figure5: Turn-on transition at 1W gate resistance and 15V driving voltage. an unusually high voltage rating for the ponents on the printed circuit board. and an attractive flat form factor. The The fastest switching of the power insulation of the planar transformer. The The 1SC2060P uses the latest SCALE-2 500kHz gate drive module has been gate can be obtained by letting both 1SC2060P provides galvanic isolation chipset to reduce the component count extensively tested for performance and sides of equation (2) be equal. The gate up to 1.7kV – enough even for future by 80%. Supporting passive compo- reliability under harsh environmental current in this critically damped case generations of MOS switches. nents have been carefully selected for conditions. exhibits the steepest slopes possible for appropriate voltage rating, temperature www.ct-concept.com non-oscillating waveforms. It is interest- Planar transformers for high-voltage range and degradation over time. ing to note that there is a maximum peak drivers are not only characterized by current for which the gate loop remains high power density and cost-effective The high-voltage insulation needs to free of oscillations. The upper limit of automated manufacturing, they also ex- withstand thousands of thermal cycles, that current is given by equation (3). cel in high-speed switching due to their over-voltage peaks, mechanical stress, low stray inductance. the influence of humidity and many more parameters. Planar transformers on the (3) Reliability printed circuit board benefit from the Power systems are generally designed high stability of fiber-reinforced epoxy Figure6: Schematic cross section of the HV planar transformer. to ensure high availability throughout that has proved to maintain its char-

36 Power Systems Design December 2008 www.powersystemsdesign.com 37 Power Supplies Power Supplies

expel heat generated during DC to DC dissipation Innovation in DC/DC Design conversion so that the circuit and sur- 3. Current sharing capability to spread The innovation is a modular but rounding ICs do not over heat. Such the heat evenly, eliminate hot spots and surface-mount approach that uses High-Power, High-Density solution requires an innovative design to minimize or eliminate the need for heat efficient DC/DC conversion, precise meet these criteria: sinks current sharing and low thermal imped- 4. Complete DC/DC circuit in a sur- ance packaging to deliver the output 1. Very low profile for efficient air flow face-mount package that includes the power while requiring minimal cooling. Power Supply with Optimum and to prevent thermal shadow on sur- DC/DC controller, MOSFETs, inductor, A system using this solution depends on rounding ICs capacitors and compensation circuitry fewer fans or slower fan speed, as well Thermal Performance 2. High efficiency to minimize heat for a quick and easy solution as few to no heat sinks. These contrib- Paralleling for complete DC/DC µModule regulator systems

Most of us are so accustomed to the easy accessibility of a wide variety of premium quality digital information that rarely is anyone aware of the technological battles on the background to innovate faster and more powerful routers, switches, servers and storage devices that are necessary to manage this massive traffic of ones and zeros. And as the battle for digital design prowess for more sophisticated systems intensifies, these innovations in faster data processing and computing are creating systems that generate so much heat, more money is spent on cooling the equipment in order to keep them operating reliably.

By Afshin Odabaee, Product Marketing Engineer and Alan Chern, Assistant Applications Engineer, Power µModule Products, Linear Technology Corp.

ased on a study sponsored by cluster and finally to each server farm. (height) possible to allow smooth flow AMD and conducted by Law- The battle to control heat dissipation of air for cooling. The power supply had Brence Berkeley National Labora- and distribute power more efficiently to be surface-mountable and operate tory, in 2005 the total power consump- has also intensified. at high enough efficiency to minimize tion of US servers was 0.6% of the heat dissipation. He also demanded the overall US electricity consumption. This The optimum operation and reliability simplest possible solution so his time figure doubles to 1.2% when the cost of these digital equipments highly de- could be dedicated to the more com- of cooling equipment is added. This is pends on the performance of the DC/DC plex tasks. Aside from precise electrical more than the electricity consumed by converters that are used as distributed performance, this solution must quickly color televisions. DC power for IC such as FPGAs, ASICs, transceivers and memory modules as The increase in power consumed by well as RF amplifiers and sensors. Also, these systems is also motivating DC/DC aside from the electrical performance regulator designers to introduce new such as the accuracy of regulation or methods for better power and thermal transient response to a varying load management. Power management and current, the thermal performance has heat dissipation has become such a become a more crucial factor in select- crucial factor for these system designers ing a DC/DC regulator. that the decision of selecting a DC/DC Figure 1. Four DC/DC µModule regu- regulator is no longer just limited to In a recent discussion with a sys- lator systems current share to regulate satisfying the load requirement such as tem designer, the requirement for his 1.5V at 48A with only 2.8mm profile the core and I/O supplies on a FPGA. A power supply was to regulate 1.5V and and 15mm x 15mm of board area. larger scale is now influencing the selec- deliver up to 40A of current to a load Each µModule weighs only 1.7g and tion of these DC/DC regulators starting that consisted of four FPGAs. This is up has an IC form-factor that can easily from each IC as its load, to each PCB, to 60W of power that must be deliv- be used with any pick-and –place Figure 2. Simply parallel multiple DC/DC µModule regulator systems to achieve higher output current. Board layout is as easy as to each rack, to each cabinet, to each ered in a small area with lowest profile machine during board assembly. copying and pasting each block.

38 Power Systems Design December 2008 www.powersystemsdesign.com 39 Power Supplies Power Supplies

taken care of within the µModule a rough estimation of the surface tem- package; there are no external induc- perature on each module. Cursors 5 to 7 tors, switches or other components indicate the surface temperature of the to worry about. PCB. Notice the difference in temperature between the inner two regulators, cursors Additional features include output 1 and 2, and the outside ones, cursors 3 voltage tracking and margining. The and 4. The LTM4601 µModule regulators switching frequency, typically 850kHz placed on the outside have large planes at full load can be adjusted by an to the left and right promoting heat sink- external clock for synchronization ing to cool the part down a few degrees. should frequency harmonics be a The inner two only have small top and Figure 3. By operating each DC/DC concern. Figure 6: Bottom layer planes for figure 1 circuit. bottom planes to draw heat away, thus µModule 90º out-of-phase, the input becoming slightly warmer than the out- and output ripples are reduced which side two. Further heat dissipation is pos- also reduces requirement for input 48A (72W) from Four Parallel sible by adding vias underneath the part. and output capacitors. Photo shows µModule Regulators Figure 4: Efficiency of the four Figure 2 shows a regulator com- Vias provide a path to the power planes individual µModule switching wave- DC/DC µModules in parallel remains prising four parallel LTM4601s, which and into the PCB, which helps draw heat forms for figure 2. high over a wide range of output can produce up to 48A (4 x 12A) voltages at 12V input. away. Vias should not be placed directly ute to a lower cost system that is also output. The regulators are synchro- under the pads. consuming less power to remove heat. nized but operate 90° out of phase with value of the top (internal) feedback resis- Figure 1 shows a test board for such respect to each other, thereby reduc- tor changes as you parallel LTM4601s. Airflow also has a substantial effect on circuit. The design regulates 1.5V output ing the amplitude of input and output The LTM4601’s reference voltage is 0.6V the thermal balance of the system. Note while delivering 40A (up to 48A) of load ripple currents through cancellation. The and its internal top feedback resistor the difference in temperature between current. Each “black square” is a com- attenuated ripple in turn decreases the value is 60.4k ohm, so the relationship Figure 8 and Figure 9. In Figure 9, a Figure 7: Top layer planes for figure 1 circuit. plete DC/DC circuit and is housed in a external capacitor RMS current rating between VOUT, the output voltage setting 200LFM airflow travels evenly from the

15mm x 15mm x 2.8mm surface-mount and size requirements, further reducing resistor (RFB) and the number of modules tors is relatively simple, in that there are the power and ground planes, as shown bottom to the top of the demo board, package. With a few input and output solution cost and board space. (n) placed in parallel is: few electrical design considerations. in Figure 5. Laying out four parallel causing a 20°C drop across the board capacitors and resistors, the design us- Nevertheless, if the intent of a design µModule regulators is just as easy, as compared to the no air flow case in ing these DC/DC µModule systems is as Synchronization and phase shifting is is to minimize the required PCB area, shown in Figures 6 and 7. If laid out Figure 8. simple as it’s shown in the photo. implemented via the LTC6902 oscillator, thermal considerations become para- properly, the LGA packaging and the which provides four clock outputs, each mount, so the important parameters are power planes alone can provide enough The direction of airflow is also im- DC/DC µModule Regulators: A Com- 90° phase shifted (for 2- or 3-phase spacing, vias, airflow and planes. heat sinking to keep the LTM4601 cool. portant. In Figure 10 the airflow travels plete System in an LGA Package relationships, the LTC6902 can be ad- inside a 50ºC chamber from right to The LTM4601 µModule DC/DC regula- justed via a resistor.). The clock signals Figure 4 illustrates the system’s high The LTM4601 µModule regulator has Figure 8 is a thermal image of Figure 1 left, pushing the heat from one µModule tor is a high performance power module serve as input to the PLLIN (phase-lock- efficiency over the vast output current a unique LGA package footprint, which (DC1043A) board with surface tempera- regulator to the next, creating a stacking shrunk down to an IC form factor. It is a loop in) pins of the four LTM4601s. The range up to 48A. The system performs allows solid attachment to the PCB ture readings at completely integrated solution—includ- phase-lock loop of the LTM4601 com- impressively with no dipping in the effi- while enhancing thermal heat sinking. specific locations. ing the PWM controller, inductor, input prise of a phase detector and a voltage ciency curve for a broad range of output The footprint itself simplifies layout of Cursors 1 to 4 give

and output capacitors, ultralow RDS(ON) controlled oscillator, which combine to voltages. FETs, Schottky diodes and compensa- lock onto the rising edge of an external tion circuitry. Only external bulk input clock with a frequency range of 850kHz Layout and output capacitors and one resistor ±30%. The phase-lock loop is turned on Layout of the parallel µModule regula- are needed to set the output from 0.6V when a pulse of at least to 5V. The supply can produce 12A (more 400ns and 2V ampli- if paralleled) from a wide input range of tude at the PLLIN pin 4.5V to 20V, making it extremely ver- is detected, though it is satile. The pin compatible LTM4601HV disabled during start- extends the input range to 28V. up. Figure 3 shows the switching waveforms of Another significant advantage of the four LTM4601 µModule LTM4601 over power-module- or IC- regulators in parallel. based systems is its ability to eas- ily scale up as loads increase. If load Only one resistor requirements are greater than one is required to set the µModule regulator can produce, simply output voltage in a add more modules in parallel. The parallel setup, but the design of a parallel system involves value of the resistor Figure 8: Thermograph of 48A, 1.5V circuit of figure 1 shows little more than copying and pasting the depends on the number Figure 5- The LTM4601’s pin layout provides simple balanced power sharing among each DC/DC µModule layout of each 15mm x 15mm µModule of LTM4601s used. This power plane placement and easy paralleling capa- and low temperature rise even without airflow (VIN=20V to Figure 9: Thermograph of four parallel LTM4601 with regulator. Electrical layout issues are is because the effective bility (copy & paste approach). 1.5VOUT at 40A). 200LFM bottom-to-top airflow (20VIN to 1.5VOUT at 40A).

40 Power Systems Design December 2008 www.powersystemsdesign.com 41 Power Supplies Power Supplies

the PCB. In Figure 10, most of the heat moves to the left side. Figure 11 shows an extreme case of heat stacking from one µModule device to the next. Each Distributed Power of the four µModule regulators is fitted with a BGA heat sink and entire board is operated in a chamber with an ambi- ent temperature of 75°C simulating an Architecture actual application.

Start-Up, Soft-Start and Current Sharing Past, present and ever-evolving The soft-start feature of the LTM4601 prevents large inrush currents at start- Distributed power architecture (DPA) is widely used in high availability applications that support complex up by slowly ramping the output voltage loads. DPA has proven to be a very flexible approach that has evolved over time to match the industry’s to its nominal value. The relation of need for efficiency, protection and changing load requirements. Figure 10: Thermograph of four parallel LTM4601 with 400LFM right-to-left air- start-up time to VOUT and the soft-start flow in 50ºC ambient chamber (12VIN to 1.0VOUT at 40A). capacitor (CSS) is: By Paul Greenland, VP Marketing, Power Management Group, Semtech Corporation

he future for DPA looks bright as it called a rectifier. providers quickly adapted their systems is the basis for the “power supply to handle voice and data to provide the Ton a chip” concept that could be To minimize corrosion, the positive ter- backbone of the Internet. This repre- the future of system design. Properly minal of the battery was the return of a sented a massive increase in bandwidth applied, a distributed power system -48V nominal supply. On each line card and content, and with that evolution, For example, a 0.1µF soft-start ca- yields a number of key advantages: was a modular DC-DC converter, com- simple loads evolved to complex loads, pacitor yields a nominal 8ms ramp (see packaging and thermal management are monly known as a brick, with multiple rendering the conventional distributed Figure 12) with no margining. simplified, higher power densities are outputs. Similar architectures also apply power architecture virtually useless. To possible, electromagnetic compatibility in military and aerospace applications. accommodate these complex loads, the Current sharing among parallel regula- is improved and both redundancy and An important characteristic of distrib- industry borrowed the DPA techniques tors is well balanced through start-up reliability are enhanced. uted power architecture is the possibil- used in personal computers where high to full load. Figure 13 shows an evenly ity of configuring a redundancy system frequency microprocessors and dual distributed output current curve for a Distributed power architectures were using more DC-DC converters than the logic ASICs represented a challenge 2-parallel LTM4601 system, as each created to address complex modular minimum required by the load. Usually (N to the traditional centralized silver box rises to a nominal 10A each, 20A total. load systems, the earliest commer- + r) converters are used, where N is the power system. Figure 11: Thermograph of four parallel LTM4601 with BGA heatsinks and 400LFM cial examples are telecom solid-state minimum number of converters required

right-to-left airflow in a 75ºC ambient chamber (12VIN to 1.0VOUT at 40A). Conclusion exchanges, shown in figure 1. The solid- to power the load and r is the number of For some time the more powerful The DC/DC µModule regulators are state exchange consisted of a series of redundant units, usually 1. microprocessors had dedicated regula- effect. The µModule device on the right, LTM4601 µModule regulators. self-contained and complete systems in rack mounted line cards powered from tors with standard specifications. Dual the closest to the airflow source, is the an IC form factor. The low profile, high a lead acid battery charged by a power Technology doesn't stand still and logic ASICs had a core, which was coolest. The leftmost µModule regula- Heat transfer to the PCB also changes efficiency and current sharing capabil- factor corrected isolated converter the telecom manufacturers and service individually powered together with an tor has a slightly higher temperature with airflow. In Figure 8, heat transfers ity allow practical high power solutions because of spillover heat from the other evenly to both left and right sides of for the new generation of digital sys- tems. Thermal performance is impressive at 48A of output current with balanced current shar- ing and smooth uniform start- up. The ease and simplicity of this design minimizes development time Figure 13: Each DC/DC µModule starts and while saving board Figure 12: Controlled soft start is important in ends by sharing the load current evenly and bal- space. proper startup of the FPGA or the system as a anced, a crucial feature to prevent one regulator www.linear.com whole; Soft-start current and voltage ramp for from overheating; Two parallel LTM4601s, as four DC/DC µModules in parallel. each rises to a nominal 10A each, 20A total. Figure 1: Conventional Distributed Power Architecture. Figure 2: The Intermediate Bus Architecture.

42 Power Systems Design December 2008 www.powersystemsdesign.com 43 Power Supplies Power Supplies

in figure 2 includes an intermediate bus troubleshooting power supply issues. filter inductor has to be approximately voltage, which has historically been 8V This extra work would be virtually half a millimeter to fit inside the pack- to 14V but is now moving below 6V. eliminated with the capability of placing age. But the promise of this solution is Lower load voltages, particularly core the power supply inside the package, enough to ensure that the DPA will be voltages are moving below 1V and large matched to its load and powered from the dominant way of designing power conversion (or step-down) ratios are a standard rail. Considerable develop- architectures to meet complex needs inefficient enough without adding in the ment work is required to make this a well into the future. turns ratio term introduced by a trans- mass production-worthy reality. For former-isolated converter, which also instance, the height or profile of the in- www.semtech.com carries an efficiency penalty. Conse- tegrated regulator solution including the quently, the reduced in- termediate bus voltage represents an improve- ment in efficiency and power density with true point of load imple- mentation.

The SC417 inte- grated buck regulator shown in figure 3 pro- vides flexibility of ap- plication together with 0/&."3,&5 high power density and complex load matching electrical performance. It was specifically de- signed to pre-regulate 0/&5*5-& CMOS point-of-load regulators, which often run from multiple or semi-regulated power Figure 3: SC417 integrated buck regulator. sources, such as the input/output (I/O) block operating from tional imperative, as utilities placed an as feature size drops below 90nm. This ubiquitous AC adapter 0/&#6: a higher voltage. The first point-of-load upper limit on the power consumed by places increased demands on the point- or lump-in-a-cord regulators were used in desktop PCs. a data centre that limited the number of of-load regulators, which have to ac- adapter. Point-of-load regulation is an attractive deployed servers at its heart. The only commodate substantial high-frequency solution particularly where energy effi- option for service providers wishing to load changes without deviating outside Distributed power ciency is required. Reduced distribution boost bandwidth and throughput is to the output voltage regulation band. This architectures are con- losses, improved steady-state and tran- improve the efficiency of the distributed is almost impossible to achieve with- tinually evolving to em- sient regulation coupled with inherent power system particularly where the out placing the regulator virtually at the brace the requirements modularity are some of the advantages ability to cool a facility is also con- terminals of the load IC, literally at the of load technology of this technique. Furthermore, the AC- strained. point of load where parasitics, especially matching, increased DC converter and point of load regulator trace inductance and resistance, may load capacity and en- may be optimized for their respective As the macro or system-level chal- be minimized. ergy efficiency. A new functions and the load is decoupled lenges multiplied, the data networking chapter to this story is from the distributed voltage reducing load technology was also evolving. This brings us to the subject of load just beginning and may crosstalk. The typical mid-range Ethernet board technology matching; the point of load end with a dedicated &.108&3*/((-0#"-*//07"5*0/ can contain as many as 40 power rails. regulator has to match the requirements regulator inside the Energy efficiency drove the adop- Many of the loads in these applica- of the load: voltage regulation, transient package with its com- $IJOB &VSPQF /PSUI"OFSJDB tion of synchronous rectification as the tions are the deep sub-micron, CMOS response, settling time and dynamic plex load. This is being regulated voltage fell below 3.3V and integrated circuits. With decreasing output impedance for optimum sys- called a “Power Supply In print and online. For Power Electronic Engineers Only. the creation of multiple operating modes feature size, integrated circuit designers tem performance. Low voltage loads, on a Chip” in some For a full media kit, contact: [email protected] such as STANDBY and SLEEP where face the challenge that the quality of the particularly those operating below 3.3V quarters. Complex the load consumes dramatically lower clock distribution and clock recovery benefit from the high-frequency switch- load IC manufacturers power when inactive. High current low circuits suffer as the VI characteristics ing capabilities of CMOS controllers and consider this to be an drop out (LDOs) linear regulators are be- of the smallest transistors degrade. I/O regulators, which have a limited input attractive scenario as ing displaced by more efficient switch- circuits, particularly those that contain voltage breakdown that is usually below they spend a dispro- ing regulators for the same reason. phase-locked loops (PLLs) become 6V. For this reason, among others, in the portionate amount of Datacom manufacturers had an addi- increasingly sensitive to noise and ripple distributed power architecture shown applications resource

revPSDE_Worldwide_Ad.indd 1 11/25/08 12:02:42 PM 44 Power Systems Design December 2008 www.powersystemsdesign.com 45 Advertisement

Ohmite

New Wirewound Tubular Lug Resistors mounting terminals, the E Series enhances Range Ohmite’s hugely successful lug offering by Available with three durable coating options; adding sizes commonly used by the European lead-free vitreous enamel, silicone-ceramic and electronics market. Rugged construction allied to our patented, flameproof Centohm cement a choice of coatings makes these resistors ideal designed to withstand temperatures to for applications requiring high wattage ratings. 2000°C, the E Series will range from 72 to 700 Watts. Available in both adjustable and www.ohmite.com fixed styles, with both live and isolated integrated

Fairchild Semiconductor

Gain a Highly Efficient and Flexible Point- complex power system requirements found of-Load Power Conversion Solution with in applications such as datacom equipment, Fairchild’s Digital Power Controllers servers, FPGA power supplies, DDR memory These digital power controllers combine power supplies and industrial control equipment. digital loop control with highly integrated power management capabilities to offer flexible, http://www.fairchildsemi.com/products/ easy-to-design power delivery solutions. digitalpower/index.html These controllers address a wide variety of

Texas Instruments

TI’s New Eight-Channel Sequencer and of equipment, including telecommunication Monitor with Non-Volatile Error Logging, switches, servers, industrial, networking and UCD9081, Supports the Latest Generation test equipment. The UCD9081 is available from Microprocessors, ASICs and DSPs, to Texas Instruments and its authorized distributors Improve System Reliability and Ease in a 32-pin QFN package. Application notes, Eequencing on Boards with Multiple Points evaluation modules and the GUI software tool of Load. for the UCD9081 are also available online at The sequencer operates from a 3.3-V supply and does not require external memory or a www.ti.com/ucd9081-pr clock, to help reduce board space in a variety International Rectifier

International Rectifier’s Latest Power conversion stage product line for computing Management Solutions. and communications applications. In addition, IR features a range of innovative products IR’s DC-DC converters and modules for and platforms addressing applications for high reliability applications, and benchmark lighting, AC-DC, audio and appliances including MOSFETs, IGBTs and high-voltage ICs for a the iMOTION™ integrated design platform for diverse range of applications will be on display. variable speed motor drive, as well as the latest X-Phase® and DirectFET® MOSFET chipsets, http://www.irf.com/whats-new/nr081028.html SupIRBuck™ family of integrated voltage regulators and iPOWIR™ integrated power ITW Paktron

Non-Polarized Polymer Film Capacitors Features “non-shorting” operation and does not (CS Series) Designed for Mission Critical crack like large ceramic chip capacitors under Applications temperature extremes or high vibration. There ITW Paktron’s Multilayer Polymer (MLP) Film are no DC or AC voltage coefficient issues with Capacitors (Type CS Series) feature ultra-low polymer film capacitors. ESR and high ripple current capability and are Capacitance values range from 0.33µF to designed for high frequency filtering and EMI/RFI 20µF and voltage ratings are 50 to 500 VDC. suppression in power conversion applications. Lead time is stock or four to six weeks. Provides mechanical and electrical stability, compared to multilayer ceramic capacitors. www.paktron.com SpecialSpecial Report Report – Renewable – Renewable Energy Energy Special Report – Renewable Energy

is usually controlled by a DSP embed- ded controller via a fiber optic link, to provide efficient and reliable switch- Industrial Fiber Optics in ing control with high galvanic isolation capability.

There are numerous rectifier and in- Renewables verter control switches available: • Insulated Gate Bipolar (IGBT) • Gate Turn Off Thyristor (GTO) • Integrated Gate Commutated Thy- Wind turbine and wind farm applications ristor (IGCT) • Symmetrical Gate Commutated

Global warming and climate changes from CO2 emissions of traditional energy sources, such as those Thyristor (SGCT) • Emitter Turn Off Thyristor (ETO) powered by fossil fuels, have created huge markets for alternative power generation. Wind turbine energy has become a popular alternative to meet the fast growing energy demand. Unlike fossil fuels, Fiber optic components are common- which are a limited and diminishing resource, wind energy is limitless and readily available. ly used to control a high voltage and current switching device, with reliable Figure 3: ETO’s two-level voltage source converter phase leg block diagram. control and feedback signals (Figures 2 By Alek Indra, Technical Marketing Engineer, Avago Technologies, Singapore and 3).

onversion of wind energy into • Condition monitoring systems Wind turbine power is used to con- Condition Monitoring System utility grade AC power requires • Wind farm networking vert kinetic energy into electrical energy Most modern wind turbines have in- Cpower electronics, such as telligent features to monitor and control rectifiers and inverters. In a high power the system to accommodate varying generation system, galvanic insulation wind conditions. For example, atmo- becomes very important to ensure the spheric sensors detect wind speed and quality and reliability of the power gen- direction. Other sensors monitor the eration. Fiber optic components offer condition and strength of the turbine’s protection by providing insulation from parts to avoid run-to-failure. high-voltage glitches and unwanted signals into power electronic devices. Wind turbines need to withstand extreme weather conditions, such as Avago Technologies offers highly reli- storms and lightning. In these types able industrial fiber optic components of conditions, it is important to ensure for data-acquisition/control and isolation that the turbine’s monitoring system is in the power generation market. Featur- designed to provide high voltage and ing out-standing performance in high current isolation. Fiber optics becomes insulation voltage and high immunity a preferred choice of medium as it offers to EMI, these products are able to be much higher voltage and current isola- installed and operate in close tion properties compared to optocou- proximity to power-carrying conduits plers and other similar components. which emit disruptive electrical inter- ference. As the demand for renewable Figure 1: Wind turbine power generation block diagram. Figure 4: Elements within a wind turbine nacelle requiring fiber communications. In the nacelle of the wind turbine (Fig- energy grows globally, wind turbine (Wind Turbine Development: Location of Manufacturing Activity, S. George and S. ure 4), short link distances using fiber designs are becoming larger and larger. Matt, “Renewable Energy Policy Project”, September 2004) optics can utilize POF (plastic optical Avago’s industrial fiber products offer a fiber) and Avago’s HFBR-0500Z prod- wide range of data-rate and link lengths through use of a generator. As wind voltage conversion from the low volt- ucts. Connectors with snap-in, latching for many applications in this power gen- conditions vary, the electrical energy age generated by the wind turbine, to and screw-in designs are various eration market. created from the generator needs to be medium/high voltage for transmission. options designers can select from. converted for usability. A rectifier, in- Avago’s versatile link sub-family allows Key applications for industrial fiber verter, transformer and filter are needed Rectifier and Inverter field connector capabilities for POF and optic components in wind turbine sys- within the wind turbine, in order for The rectifier and inverter are key com- the associated connectors, allowing for tem include: utility-grade AC power to be transmitted ponents in the wind turbine system. field repairs, maintenance and installa- • Power electronic gate driver for rec- over long distances (Figure 1). The rectifier converts noisy AC power tion. tifiers and inverters to DC power, while the inverter con- • Control and communication boards A transformer is usually installed verts DC power to clean and reliable AC Besides good isolation properties, • Turbine control units Figure 2: IGBT's Gate Driver Block Diagram. at the bottom of the tower to provide power. The switching of these devices these products provide excellent signal

48 Power Systems Design December 2008 www.powersystemsdesign.com 49 Special Report – Renewable Energy SpecialSpecial Report Report – Renewable – Renewable Energy Energy

Common Avago Fiber Optic Components Part Numbers integrity as they are immune to electro- magnetic interference (EMI). It becomes an excellent solution for monitoring system communications over long dis- Minimize Losses in Solar tances with reliable data transmission in high voltage/current applications. For greater ESD and EMI protection, Panels Avago’s HFBR-0506AMZ series offers a metalized packaging that provides excellent shielding. The SMA-styled connector also works well in areas with vibration and mechanical shocks. Rectifier technology maximizes efficiency Notes: 1. Optical link distance varies with operating data rate. Lower data rate allows longer Wind Turbine and Wind Farm Energy efficiency and ‘green power’ have become buzzwords of the semiconductor optical link distance. Networking HCS is a registered trademark of OFS Data collected from the condition industry over the last 18 months, as manufacturers introduces innovative products to meet stringent monitoring systems, with the use of new energy efficiency legislation. The industry, however, has on the whole paid little attention to short-link POF fiber links in individual the rapidly growing renewable energy market. wind turbines, are typically multiplexed into HCS (hard-clad silica) or multi- mode fiber cables. The longer link By Ian Moulding, Business Manager, Diodes Incorporated distances of HCS and multi-mode fiber may be needed if wind turbine towers enewable energy is concerned These systems are used in remote or more of the photovoltaic modules are are greater than 100meters in height. Fi- with the generation of electricity portable applications such as caravans obscured by cloud or other external ber cables are both robust, offer greater Rfrom sustainable natural resourc- and boats. Grid connected systems interference such as the overhang- resistance to harsh environmental ele- es that include biomass, hydro power, feature an additional inverter stage ing branches of a tree or when the ments and are lightweight. All of these wind power and solar energy. The solar that converts the DC input into an AC photovoltaic module is faulty. In such are requirements for vertical cabling in panels market is forecast to quadruple output that is synchronized to the public circumstances, the current is instead wind turbine towers. in value to 80 Billion dollars by 2016 electrical grid. The most successful conducted via the bypass diode. Ideally (source: Clean Edge Inc, 2007). This is example of a grid connected system is the losses during this mode of operation Industry standard connectors like the just one example of growth in renew- in Germany, the ‘feed-in’ system. This would be zero; however the conduction ST/ST-thread and SMA are all available able energy that will see it displace gas rewards individuals, who have invested losses of a PN junction diode are less

from Avago. The HFBR-0400Z series to become the second largest source of in solar power, with an attractive price than ideal as it has a forward voltage (VF) operates over both HCS and multi-mode electricity generation after coal, by 2016 for selling the electricity they produce of typically 0.6V. When 10A of current is fiber, which offer greater bandwidth and (source:IEA, 2007). back to the utility company. Such tariffs flowing from the photovoltaic cells this link distance as compared to the POF are fixed for long periods of time (twenty equates to a power loss of: solution. These parts are commonly A solar panel operates on the prin- years or more) allowing the individual used in wind turbine towers and over ciple of the photovoltaic effect, whereby investor to see the long-term benefit. As P = V*I = 0.6*10 = 6W long distance wind farm networks. a suitably doped PN junction diode will a result of this approach there has been become forward biased when photons rapid growth in the solar panel market Such losses impact the overall effi- Avago Technologies has developed a hit its surface, causing a current to flow. in Germany to such an extent that in ciency of the system and are one of the Figure 5: Wind farming configuration. series of fiber optic transmitters, receiv- Solar panels are constructed from a Germany solar power accounts for 39% factors that limit the typical efficiency of ers and transceivers for wind turbine number of photovoltaic modules that of the megawatts generated globally by a solar panel to around twenty percent. Common Avago Fiber Optic Components Part Numbers monitoring systems and networking are electrically connected in series to solar panel systems during 2007. applications. Avago offers parts from achieve a desired DC output voltage Secondly, during normal operation, 650nm, 820nm or 1300nm, which have and/or in parallel to provide the requisite The bypass diode plays a critical role current will flow through the photovol- data rates up to 160MBd to meet indus- current rating. Bypass diodes are con- in the safe and reliable operation of taic modules, as shown in Fig1b. In this try customers’ needs over various link nected in parallel with each photovoltaic the solar panel and must fully meet the mode of operation, the bypass diodes distances. module in order to provide a conduction stringent requirements of IEC61730-2 will be operating in reverse blocking path around the photovoltaic mod- Solar Safety Standards. The bypass mode and the bypass diode should www.avagotech.com ule during ‘dark’ conditions to avoid diode actually has two key functions: have a VRRM that is sufficiently large overheating. The minimization of heat is enough to block the DC voltage across essential, since overheating will reduce Firstly, as already mentioned, it pro- the terminals therefore avoiding reverse the overall efficiency of the solar panel, vides an alternative conduction path, as breakdown conditions. Moreover, it shown in Fig1a, when one or more of should also possess a low reverse leak-

Notes: Solar panel systems can be either the photovoltaic modules do not con- age current (IR) specification to prevent 1. Optical link distance varies with operating data rate. Lower data rate allows longer “off grid” or “grid connected” systems. duct due to ‘dark’ conditions. the energy stored in the battery leaking optical link distance. In the former, the DC output from the away, thereby maintaining the efficiency HCS is a registered trademark of OFS solar panel feeds a battery/charger. These conditions occur when one or of the system.

50 Power Systems Design December 2008 www.powersystemsdesign.com 51 Special Report – Renewable Energy Special Report – Renewable Energy

PowerDI5TM. With a footprint of just 23.8mm2 the PowerDI5TM provides an 87% reduction in board space and a similar reduction in profile when compared with traditional power packages such as D2Pak, enabling bypass diodes to be integrated into the solar panel array instead of the junction box.

Innovations such as the super bar- rier rectifier technology, are contribut- ing towards significant improvements in typical solar panel efficiencies. It is expected that innovations such as these and others in material science for example will contribute towards improving the efficiency of a solar panel from, typically 18% today to 30% within the next few years.

www.diodes.com

Figure 2: Comparison of IR against ambient temperature for SBR vs Schottky Diode.

Figure 1a: Bypass diode operation during partial shade conditions. Figure 1b: Bypass diode operation during normal conditions.

Schottky diodes are an attractive of solar panel applications can be met. This represents a reduction in by- TM A Powerful alternative to PN diodes since they pos- Super Barrier Rectifier (SBR ), a unique pass diode power dissipation of 57%.

sess a lower forward voltage (VF) at rea- patented power rectifier technology from Therefore, the lower VF of Super Bar- sonable leakage currents (I ). However, Diodes Incorporated meets the need. rier Rectifiers significantly reduces the R Combination the lower reliability of the Schottky metal SBR utilizes a metal oxide semiconduc- power dissipation in the bypass diode, is a new barrier contact within the device limits tor (MOS) process, to manufacture a increasing solar cell power generation PowerPack and ePowerPack its operation at high temperatures, and superior two terminal device that has a and overall efficiency. Similarly, the high- advertising program in print and online designed to promote your company’s new products, seminars, reduces its reverse and forward surge lower forward voltage (VF) than compa- er stability of SBR at higher temperature withstand capability. Consequently, the rable Schottky diodes, while possessing is illustrated in Fig 2. and announcements while driving traffi c to your performance of a Schottky diode de- the thermal stability and high reliability company’s website. grades rapidly with temperature, limiting of PN junction diodes such as ultrafast This demonstrates that the SBR has a

the junction temperature (TJ) of a typical diodes. higher specified maximum junction tem- Advertisers receive a 100 word listing, plus product

Schottky diode to 150oC. In order to perature (TJ) than a Schottky diode and photo and url link in print to 20, 357+ subscribers comply with the thermal test require- The SBR10U45SP5 is one of a family ensures that it meets the requirements of Power Systems Design’s magazine and online ments of IEC 61730-2 the junction tem- of bypass diodes that Diodes Incorpo- of IEC61730-2. It is therefore signifi- through ePowerPack e-newsletter which is delivered perature of the bypass diode must be rated has introduced to meet the needs cantly less likely to enter into thermal every month to an audience of 24,000 power elec- able to support 170oC, depending upon of the rapidly growing solar panel mar- runaway. tronic engineers in Pan Europe and 32,000 power

the forward voltage (VF) of the diode. ket. As can be seen, from table 1, the design engineers in North America. To participate Schottky diodes are therefore unsuitable device has a typical forward voltage (VF) An additional benefit of the super bar- contact: [email protected] for use as a bypass diode. of just 0.38V. Substituting this device rier rectifier technology is that it is a high into the earlier equation would result in: density process, enabling high perfor- It is clear from the preceding dis- mance devices to be specified in small cussion that there is a need for a two P = V*I = 0.38*10 = 3.8W footprint low profile package such as the terminal that pos-

sesses low (VF), low leakage current (IR) Power Systems Design Power Systems Design and high reliability at high temperatures, PowerPack PowerPack in order that the stringent requirements Table 1: Summary performance of an SBR diode under IEC61730-2 thermal test.

52 Power Systems Design December 2008 www.powersystemsdesign.comPowefulComboAd.indd 1 3/13/08 5:58:47 PM 53 SpecialSpecial Report Report – Renewable – Renewable Energy Energy Special Report – Renewable Energy

with power levels ranging from just under a kilowatt to several hundred kilowatts. These conven- Democratizing Solar tional inverters are often installed indoors or in protected chambers to protect them from extreme temperatures, dust, and rain. The AC PV modules lead the way system is built by wiring the PV panels into an array of parallel As the world faces the economic, environmental, and political consequences of its heavy dependence strings, each consisting of a suit- able number of series-connected on fossil fuels for energy, the search for a suitable alternative only grows more intense. panels. The array output is routed to the inverter dc-input. String By Nasser Kutkut VP Technology Development and Hussam Al-Atrash, inverter inputs are typically de- Principal Engineer, Petra Solar, Inc. signed for a high DC voltage of 150-700V. he collection of solar energy tives and rebates, the payback time on designed to behave as AC current through photovoltaic (PV) cells is a a PV system remains excessive, which sources. As such, they are designed String inverters suffer from a Tparticularly promising technology. cripples the growth of the distributed PV to push high-quality sinusoidal output number of drawbacks including Sunshine is an abundant resource, while market. current in phase with the grid voltage. multiple single point failures (pan- PV technology is clean, quiet, and suit- The amplitude of this output current is els or inverter), a high-voltage DC able for distributed installations. Grid- Conventional String and Multi-String dependent upon the amount of power string configuration, which repre- tied PV technology allows the integra- Inverters available from the PV source deter- sents a safety hazard, and costly tion of PV resources into the utility grid The dc-ac inverter is at the heart of mined through a maximum power point installations as they require spe- near points of load. a grid-tie PV system. Its main func- tracking (MPPT) process. cial training and special protec- tion is to convert the PV output energy tion measures which adds to the Figure 2: Multi-string inverter system architecture. Today, cost is the primary challenge from its raw variable DC form to a grid- Conventional grid-tie inverters can overall system cost. All wiring is facing PV power systems. Presently, the compatible AC form. Grid-tie inverters be generally classified into string and to be enclosed in special conduit, solar electricity price index ranges from are designed to work with the grid, a multi-string inverters. String inverters, and DC protection fusing and dis- 21.41¢/kWhr for industrial applications stiff AC voltage source and thus are as shown in Fig. 1, are large inverters connects are required. Moreover, to 37.78¢/kWhr for residential firemen and service people need applications. This price index is to be careful around such an primarily driven by PV module array. The array is especially dan- cost (~40%-50% of system gerous when the inverter or the cost), inverter cost (<10% of utility is absent, since the voltage system cost), balance of the would be highest! system costs (~10%-20% of system cost), and labor and in- Successful string inverter in- stallation costs (~30%-40% of stallations require careful system system cost). Since the inverter design. Miscalculation of worst- cost constitutes a small per- case maximum open-circuit volt- centage of the overall system age of a panel string is a common cost (<10%), a major reduction cause of inverter failure. Panels in inverter cost will not have a within a string need to be very major impact on overall system closely matched: same manufac- cost. On the other hand, soft turer, age, condition, and orienta- costs (labor and installation) tion. This is because one weak or constitute more than 1/3rd of degraded panel would limit the the system cost. Reducing power output of the whole string. these costs can result in major Since string inverters implement Figure 3: The AC PV module. reduction in overall system a single MPPT process, special cost. attention is needed to ensure that process is applied to each of these trained personnel adding to the overall a string does not get partially shaded by panel strings. This allows the panels to system costs. Grid-tied PV cannot yet a chimney, a tree, or nearby objects. be grouped into a number of smaller compete with the cost of com- groups, as shown in Fig. 2. A problem Micro-inverters and the rise of the AC mercial power generation on a Multi-string inverters present a partial in one group does not affect the other PV Modules $/kWh basis. The result is that solution to string inverter drawbacks. A groups. However, similar to string in- Micro-inverters are small grid-tie grid-tied PV is heavily depen- multi-string inverter accepts several dc verters, multi-string inverters feature a inverters with power levels ranging from dent on government incentives input circuits and processes their power hazardous high voltage dc bus and still 150-250W and are designed to handle a and rebates. Even with incen- Figure 1: String inverter system architecture. independently. An independent MPPT require installation by specialized and single PV panel. In this type of system,

54 Power Systems Design December 2008 www.powersystemsdesign.com 55 Special Report – Renewable Energy SpecialSpecial Report Report – Renewable – Renewable Energy Energy

inverter designer is working against the economies of scale. A micro-in- verter is still required to perform the same functions as a string inverter, Reliability in Renewables typically 15-25 times larger! Com- ponents do not scale down properly ® in size, cost, power consumption, or performance. Many, such as the Hi-Rel SKiiP IPM´s undergo unique burn-in controller, do not scale down at all. The addition of circuits for efficiency improvement and/or extra protec- under worst case conditions tion features is often not feasible. Young developing markets such as wind power generators, solar power, electric vehicles, welding

The micro-inverter reliability machines, electric drives, lifts, power supplies, conveyor belts and trams need highly robust solutions. requirements are even more chal- As a significant innovator in the power electronics sector, many of Semikron’s progressive developments lenging. Micro-inverters are located behind the panels making mainte- have been accepted as industrial standards. nance difficult or impossible. Micro- Reported by Cliff Keys, Editor-in-Chief, PSDE inverters are thus required to be far more reliable than string inverters. he high operational reliability of powers 44 Gigawatt installed wind pow- standard modules. SKiiP has no base In addition, the MTBF for a micro- the SKiiP IPM´s is further stressed er capacity. The total wind power ca- plate and less solder layers resulting in inverter needs to be quite high Tand tested during unique burn-in pacity installed is 94 Gigawatt. (Source: lower thermal-mechanical stress inside and ideally matching the PV panel. tests only offered by SEMIKRON. Com- BTM Consult ApS, 03/2008) More than the module. The thermal cycling capa- This is especially challenging since pared to suppliers of standard modules, 15 years of experience in pressure con- bility is five times higher than a standard these inverters are installed out- this test is possible because of the high tact technology is integrated into this module with base plate and is reached doors and are exposed to extreme integration of the module. The power power module. even under the harsh climatic conditions temperatures and weather. Electro- semiconductor, gate driver, current sen- renowned in the wind energy indus- lytic capacitors used in inverters are sors, protective functions and matched The principle of the technology is to try. High load and temperature cycling Figure 4: AC PV module based solar power system. especially susceptible to elevated cooling are already integrated in the use mechanical pressure pressing the capability is ensured with the patented temperature and can become the IPM. SKiiP is the only intelligent power DBC to the heat sink without soldering. SKiiP pressure contact technology. The a micro-inverter is connected to a single their improved energy harvesting com- limiters of inverter life-time. module in this power range for the wind This results in a homogenous pressure module is available in 1200V and 1700V panel and is installed close to it. The pared to string or multi-string invert- market. During the burn-in test the mod- distribution with a thermal connection for currents from 500A to 2400A. inverter AC output is directly routed to ers. Since the integrated micro-inverter Conclusion ule is operated in a one or four-quadrant between the ceramic substrates carrying the AC breaker box. No series or paral- operates with a single panel, a true In summary, the AC PV module is modus and tested at elevated tem- the semiconductor chips and the heat According to the European Renew- lel DC connections are made between per panel MPPT is implemented which poised to truly “democratize solar” as perature and elevated voltage. The test sink. An improved thermal resistance able Energy Council, renewable ener-

panels, leaving all DC wiring at a low maximizes the power output from each it offers a budget friendly incremental ensures higher reliability of the inverter (Rth(j-s)) of 40% is reached compared to gies will cover more than 35% of energy voltage level of a single panel (typically panel in a system. Recent studies have installation. Unlike string inverter based in the wind power plant. needs worldwide by the <60Vdc). shown upward of 20% increased energy system where a base residential sys- year 2030. Against the harvesting with micro inverters. tem cost could approach upwards of SKiiPs are operated backdrop of a dynamical- Taking the granularity one step further, $25,000, low budget end users can for approximately two ly growing market, these an AC PV module is a factory assem- Finally, and since each AC PV module get started with few AC PV modules to hours under worst case intelligent integrated bled micro-inverter integrated into a PV includes an integrated micro-inverter, supplement their power usage and add real inverter conditions modules are ideal for use panel. In such a configuration, the DC larger solar power systems are AC more modules as they go. This is the at elevated temperature in wind generators and wiring is not accessible to the user and coupled where the output of the AC PV true spirit of democracy. and elevated voltage. reduce production times the output of the integrated module is modules are connected in parallel (Fig. All root causes of early and consequently, the all- AC. Fig. 4 shows a typical AC PV mod- 4). As a result, the AC PV modules do www.petrasolar.com failures are identified and important time to market. ule architecture. not need to be matched thus allowing eliminated. SKiiP under- end users to mix and match panels from goes one of two burn-in Digital driver – proven The AC PV module is the first modular various manufactures and with varying cycles. The modules are control platform for solar power system that greatly sim- power levels. This greatly increases flex- tested with cooling water IGBT modules and sys- plifies system design and eliminates ibility and eliminates single point failures at 80°C and cycling at a tems safety hazards. In addition, and since thus providing for true redundancy. constant chip tempera- The digital driver SKY- no DC wiring is accessible, installation ture. Junction tempera- PER 52, which has al- is greatly simplified and can be easily AC PV Module Design Challenges ture of the silicon reaches ready proven to be a suc- performed by any electrician and/or end Since the core of an AC PV mod- temperatures of up to cess in driving IGBT mod- users. This translates into significant ule is the micro inverter, the market 140° (IGBT3) to ensure ules, is also being used in savings in installation costs and leads to would thus require micro-inverters to high stress levels for the SEMIKRON systems. This lower overall system costs. compete with string inverters in terms module. SKiiP is the only intelligent power module for the wind market driver boasts a wealth of of performance, cost (per Watt), and with power semiconductor, gate driver, current sensors, protective functions with a minimum Another benefit of AC PV modules is efficiency. This means that a micro- The SKiiP IPM´s now functions and matched cooling already integrated. of components, making

56 Power Systems Design December 2008 www.powersystemsdesign.com 57 Special Report – Renewable Energy SpecialSpecial Report Report – Renewable – Renewable Energy Energy

that integrate power semiconduc- that the gate driver can process the low- tor, cooling, capacitors, driver and voltage 3.3V and 5V controller signals controller hardware. without the use of a level converter. Im- munity to interference signals is thereby Renewable Energy The SKYPER digital driver improved. The powerful SKYPER 52 transmits the commands of the driver can be used in applications with controller for the power semicon- currents of up to 9000 A and frequen- ductor with a high level of signal cies of up to 100KHZ. The galvanic Efficiency integrity, i. e. clear logic levels. As isolation between the controller and a result, the resistance to inter- power modules can withstand voltages ference factors is improved. The of up to 4KV. The digital driver is ROHS- flexibility of this driver is owing to compliant and suitable for 1200V and Real-time control is affordable solution the fact that the switching proper- 1700 V IGBT modules. The digital driver SKYPER 52 offers a high ties can be programmed individu- Throughout the world, there is an increasing demand for renewable energy, yet system manufacturers level of signal integrity, providing reliable im- ally. Voltage variation can thus In contrast to analog solutions, Semi- continue to face the same issues that have always slowed the growth of this technology: increasing the munity from interference signals. be optimised and EMI immunity kron’s digital technology offers many guaranteed. Complex filter cir- benefits from complex functions. The total amount of power gathered and decreasing cost per watt. the digital driver even more flexible and cuits are no longer needed, which demand for easy integration of the gate robust than before. SKYPER 52 offers saves the user money. Thanks to the control into converter solutions and the By Arefeen Mohammed, Texas Instruments C2000 Systems & a high level of signal integrity, provid- increased number of functions offered fusion of driver and controller interfaces Applications Engineer Houston, Texas Instruments ing reliable immunity from interference by SKYPER 52, additional settings such confirm the need for a versatile digital signals. The digital driver communicates as sequential IGBT turn-off in the event control platform. olar power has been around for The inverter’s role and stages and several hundred kilowatts peak via CAN input/output, providing the op- of malfunction are possible. years and, if all goes well, may The main function of the inverter is to (KWp), allowing inverters to be designed timum interface between controller and www.semikron.com Sgrow by $21 billion by 2017, ac- convert variable direct curre nt (DC) volt- around sophisticated source topologies, power module. As a result, this driver is SKYPER 52 works with low-voltage cording to IMS research. One important age input from the source into a clean either with or without transformers, and particularly suitable for use in systems differential signal transmission, meaning way to help achieve these goals is by sinusoidal 50- or 60-Hz output for use with the integration of multiple control adding greater intelligence to the control by appliances and/or feeding back into processors. Figure 1 shows where the of the inverter, which converts the vari- the grid. Single or multiple phases may inverter fits into an all-inclusive photo- able voltage output of the collector into be required by different applications. In voltaic (PV) system that not only charges a steady voltage that is used for running addition to DC/AC conversion, inverters a battery and drives local AC loads, but applications or charging batteries. Intel- perform such functions as disconnect- also ties to the grid and has an alter- ligent inverters maximize power transfer ing the circuit to protect it from power nate power source in the form of an AC from the gathering source, synchronize surges, charging the battery, logging data generator. Similar configurations apply 0/&."3,&5 power output with the electrical utility, on usage and performance, and maxi- to wind turbines and other sources. and protect the local system from po- mum power point tracking to keep power tentially damaging changes in the grid. generation as efficient as possible. Transformers and protection Because the source input is usually While sun- and wind-powered sys- Nominal power ranges between one not high enough, the system can either 0/&#00, tems are obvious applications, intelligent &.108&3*/((-0#"- inverters can also benefit other sources *//07"5*0/ of power, such as fuel cells, in order to maximize output. For all such applica- $IJOB &VSPQF /PSUI"OFSJDB tions, highly effective inverter control is 0/&#6: available from 32-bit real-time microcon- In print and online. trollers (MCUs), which have been shown For Power Electronic Engineers Only. to cut conversion efficiency losses in For a full media kit, contact: half while significantly reducing costs. [email protected] The increased cost of using a 32-bit processor can be mitigated by choosing a modern MCU that can handle most of the entire system’s requirements, includ- ing AC-DC conversion, DC-DC con- version, and communication between panels in addition the demands of the inverter itself. In addition, cost-effective, highly integrated MCUs with real-time control capabilities are now available, enhancing performance and making the job of programming complex algorithms easier. Figure1: PV and generator hybrid system.

58 Power Systems Design December 2008 www.powersystemsdesign.com 59 Special Report – Renewable Energy Special Report – Renewable Energy

step up the voltage with a transformer tined to happen in solar inverter design, version stage. Just as an AC transformer algorithms allowing the on the AC side or boost it in the DC/ perhaps the most important feature for inherently provides galvanic isolation, so main CPU to handle I/O DC conversion stage. Just as an AC an MCU is software programmability. does a phase-shifted full-bridge DC/DC and feedback loop metrics transformer inherently provides gal- This feature would allow the highest de- converter with zero voltage switching, resulting in up to 5 times vanic isolation, so does a phase-shifted gree of flexibility in power circuit design thus making the latter equivalently a increased performance for full-bridge DC/DC converter with zero and control. transformer. some real-time control ap- voltage switching, thus making the lat- plications. ter equivalently a transformer. Figure 2 Load balancing control is required Obtaining maximum charging power shows a commonly used DC/AC circuit when the panels are connected in paral- The efficiency of battery charging The combination of 32-bit with transformer for single-phase inver- lel. The MCU must be able to detect the depends on the input voltage, which performance, enhanced sion, based on an H-bridge configu- load current and increase or decrease can be highly variable, depending on peripherals and small pack- ration controlled by four pulse-width the output voltage by turning off the wind conditions for a turbine, or sea- age sizes allows designers modulated (PWM) signals. output MOSFET. This requires a fast on- son, cloud cover and time of day for PV to add real-time control and chip ADC to sample the voltage and panels. Battery conditions vary, too, de- system management with Transformers add weight, bulk and current. pending on the charge state, so some- a single Piccolo microcon- cost, and they also cause a reduction in times it may be necessary to adjust troller. efficiency of about two percent. On the Since the source input is usually not the voltage and current ratio in order to other hand, they increase circuit pro- high enough, the system can either step increase the total power delivered and Micro-inverters tection and human safety by isolating up the voltage with a transformer on the speed charging. Maximum power output of voltage and current is at its peak, A 32-bit real-time microcontroller A relatively new option for optimizing the two sides of the circuit electrically, AC side or boost it in the DC/DC con- to the battery occurs when the product the maximum power point (MPP). MPP An example of a microcontroller with solar system efficiency and reliability is preventing a DC fault from flowing to tracking (MPPT) is designed to deter- advanced real-time control capabilities to use micro-inverters that connect to the AC side, and an AC leakage cur- mine this point and adjust the DC/DC is Texas Instruments Piccolo™ series of each individual solar panel. Equipping rent from developing a potential issue voltage conversion in order to maximize microcontrollers. The Piccolo devices each panel with its own micro-inverter between PV panels and ground. The the charging output. MPPT can increase feature architectural advancements and allows the system to accommodate its design may include a residual current the overall efficiency of a solar system enhanced peripherals in package sizes changing load and atmospheric condi- protection device (RCD) that monitors by a third or more during winter months, starting at 38-pins to bring the benefits tion, which provides optimal conversion the currents of all phases, and then trips and its effect in other types of systems of 32-bit real-time control to applica- efficiency for both the individual panels the relay if the current exceeds a certain can be significant, too. Figure 3 shows tions like micro-inverters that demand and the entire system. value. Because of the risk of current how the determination of MPP can vary lower overall system costs. In addition, leakage, RCDs are especially important with different conditions. members of the Piccolo MCU series Micro-inverter architectures also en- for safety in transformerless systems. have integrated dual on-chip 10MHz os- able simpler wiring, which translates The most common algorithm for cillators for clock comparison, on-chip into lower installation costs. By making Protection of the system mandates determining MPP is for the controller to VREG with power on reset and brown consumers’ solar power systems more inclusion of a relay to protect the con- perturb the panel’s operating voltage out protection, multiple high resolution, efficient, the time taken for the system version and charging circuitry against with every MPPT cycle and observe 150ps PWMs, a 12-bit, 4 mega-sample/ to “pay back” on the initial investment voltage surges and spikes on the grid. the output. The algorithm continues s ADC and interfaces for the I2C (PM- for the technology shortens. In addition, if a power line is dam- oscillating around the MPP over a Bus), CAN, SPI, UART communications aged or the utility has to shut it down, wide enough range to avoid local but protocols. A key to renewable energy the inverter needs to stop feeding out Figure2: DC/AC stage with transformer. misleading peaks in the power curve Renewable energy systems are electricity to the utility. A “non-islanding” caused by, say, movement in cloud Performance is a critical characteristic continually being improved in order to inverter senses that the line has been cover or a brief wind lull. To the extent for micro-inverters. Although Piccolo achieve greater efficiency that will lower de-energized, is under- or over-voltage, that the perturb and observe algorithm devices are less expensive and have a the cost per kW. While much attention is or has a significant disturbance for oscillates away from the MPP in each smaller footprint than other C2000™ deservedly paid to improving PV panels whatever reason. When this happens, cycle, it is inefficient. An alternative, MCUs members, Piccolo devices and wind turbines, intelligent invert- the inverter automatically disconnects the incremental inductance algorithm, retain the powerful the 32-bit TM- ers can also contribute to making the from the utility grid, thereby not becom- solves the derivative of the power curve S320C28x™ CPU, which makes com- technology more feasible. Variability in ing an electricity generating “island.” for 0, which is by definition a peak, then putationally intensive control algorithms regulatory and operational requirements settles at the resolved voltage level. more efficient. Peripherals such as makes it important to select the right Safety and programmability While this approach does not have the enhanced pulse width modulator controller for the inverter, a controller An unexpected but highly valued fea- the inefficiency caused by oscillation, (ePWM) support the industry’s highest that provides high performance, integra- ture of a 32-bit MCU intended for solar it risks other inefficiencies because it resolution with frequency and duty cycle tion and flexibility. The expanded use inverter applications is dual on-chip may settle at a local peak instead of the resolution down to 150 picoseconds. of micro-inverters for a range of appro- oscillators, which can be used for clock MPP. A combined approach maintains priate applications is one step toward failure detection to enhanced reliability. the level determined by the incremen- TMS320F2803x devices offer 60MHz moving solar power out of the shadows. The ability to run two system clocks tal inductance algorithm, but scans at performance plus a new Control Law New real-time microcontrollers will con- simultaneously can also be helpful in re- intervals over a wider range to avoid Accelerator (CLA), a 32-bit floating point tinue to help improve the efficiency and ducing problems when the solar panels selecting local peaks. This approach, s/w programmable math accelerator lower the cost of renewable energy. are being installed. while the most efficient, also requires that operates independent of the the greatest amount of performance on C28x™ CPU. The CLA is designed www.ti.com Because so much innovation is des- Figure3: MPP for different conditions. the part of the controller. to run complex, high-speed control

60 Power Systems Design December 2008 www.powersystemsdesign.com 61 C M Y CM MY CY CMY K

2009 International Exhibition & Conference for POWER ELECTRONICS INTELLIGENT MOTION POWER QUALITY 12 – 14 May 2009 Exhibition Centre Nuremberg

Power for Efficiency!

Mesago Veranstalter/Organizer: PCIM Mesago PCIM GmbH, Rotebühlstr. 83-85, D-70178 Stuttgart, Tel. +49 711 61946-56, E-mail: [email protected] Progress vs. Politics

Reported by Cliff Keys, Editor-in-Chief, PSDE

o-one except perhaps the oil up solution for key industries in New moguls wants dependency on York City including financial services, Nfossil fuels. Alternative energy hospitals and healthcare firms in the sources can be expensive and have event of a disaster. It will host a round- a poor conversion rate. Researchers table discussion to explore the newest at U.S. Department of Energy’s Na- trends in improving data center energy tional Renewable Energy Laboratory efficiency. The panelists will examine (NREL) have set a world record in solar how practitioners can take advantage of cell efficiency. They have been able to innovative design concepts as well as transform 40.8% of the light that goes regional resources and economic incen- through the cell into energy. This is tives to maximize return while minimiz- the highest recorded efficiency of any ing costs. photovoltaic device. The new solar cell, designed for space satellites and terres- With all the politics currently involved trial concentrated photovoltaic arrays, in the plight of US motor companies, uses gallium indium phosphide and it’s refreshing to see that Aptera Motors, gallium indium arsenide to split the solar founded in 2004 in California, to de- spectrum into three parts. The three ing it easier to achieve. The Government velop and build the safest, most energy spectrums are absorbed by the cell’s is also facing pressure from business efficient commuter vehicles on the road, three junctions more efficiently. groups for failing to move fast enough begins volume production of its first on climate change. vehicle, the all-electric 2e, in 2009. With The EU is discussing the new energy streamlined aerodynamic design, light- directive to produce 20% of power, US datacenters produce more weight composite structures and unique including fuel and electricity, from greenhouse gases than Argentina and drive systems, the two-seater offers renewables by 2020. The UK energy the Netherlands combined, according consumers fuel efficiency levels that are and climate change minister said that it to a McKinsey study. Recognizing the the equivalent of up to 127km per Liter was important that the EU come to an tremendous energy consumption of (300 miles per gallon). agreement to set an example to the rest these centers, architects, CTOs, power of world. But it is reported that environ- company executives, and regional Nice to finish on good news! ment groups are angry that the minister leaders are now partnering to create is arguing for a deal while behind the more energy efficient data facilities. www.powersystemsdesign.com/ greenpage.htm scenes the UK is pushing to remove Wall Street West is a federal and state aviation from the EU 2020 target, mak- funded initiative to develop a total back-

64 Power Systems Design December 2008