Transformative Power Semiconductor Technologies to Impact 21st Century Energy Economy, and Space and Defense Electronics Krishna Shenai, PhD Professor Electrical Engineering and Computer Science University of Toledo Birck Nanotechnology Center Purdue University West Lafayette, IN July 8, 2010 Our Research Material Technologies The Interface Advanced Systems Today’s AC Power Grid Step Up Voltage Transformer Step Down Voltage 3 Phase 155,000 to 765,000 Volts Transmission Loss AC Power Transformer (7,200 Volts) Electro Mechanical Switches 7,200 volts Power Generator Transmission Substation Generation Loss High Voltage Distribution Transmission Lines Substation Distribution Loss Transformer 120 volts AC 60 Hz Residential Industrial Consumer Consumer Commercial Consumer Reference: www.epri.com Electricity Technology Roadmap EnergyEnergy EfficiencyEfficiency End Use Utilization Incandescent Bulb 12% Efficient Light Generation Transmission & Distribution Electricity ~ 4 Units 35 % Efficient 93% Efficient ~ 32 Units Coal Electricity ~ 32 Units Compact Fluorescent Lamp 100 Units ~ 35 Units 22% Efficient Light Energy Loss From Generation through End-Use ~ 7 Units Reference: www.epri.com Energy Efficiency: A Renewed Imperative LightLight EmittingEmitting DiodeDiode (LED)(LED) New energy law approved by US Congress to ban incandescent bulbs by 2014. Replace existing incandescent with Compact Fluorescent Lamp (CFL) and LED beginning 2012. IncandescentIncandescent LightLight BulbBulb LED CFL Incandescent Life Span 50,000 hours 8,000 hours 1,200 hours Compact Fluorescent Lamp Power 6 - 8 watts 13-15 watts 60 watts Consumed Annual $42.16/year $84.32/year $361.35/year Operating Light Emitting Diode bulb Cost* * Usage of 30 bulbs 5 hours a day Reference - www.mrbeams.com/index.asp?PageAction=Custom&ID=2 www.worldnetdaily.com/news/article.asp?ARTICLE_ID=59298 What is the problem? Cost Efficiency Reliability Security Environmental Impact Utilization Generation The Opportunity • The greatest technical achievement of the 20th century is the electrification - Thomas Edison • Silicon will reconfigure today’s fragile electric power grid just the same way as it did the information infrastructure of the 20th century - Morgan Stanley • Information-quality power is the greatest business opportunity of our time – George Gilder • A perfect power system is the one that has plentiful of energy and never fails its customers - Bob Galvin Perfect Power System 20th Century Wireless Information Technology Perfect Power System - Plentiful green energy, secure and reliable 21st Century Green Energy & Power Technologies Utilization of Distributed Renewable Energy Generators (DREGs) • Chip-Scale Power – up to few hundred Watts • Medium Power – from few hundred Watts to few hundred kilo Watts • Utility-Scale Power – more than a few hundred kilo Watts Solar-Powered Data Center Why Solar-Powered Data Centers? Features of PV DC/DC Converter: • 1.5% of US electricity used • 98% efficient SiC Boost Converter • $4.5B annual electricity bill • Integrated smart PPT • > 2X increase in electricity need by 2011 • Smart load balancing • Efficient PV integration into DC system • Wireless smart control • 4% - 6% efficiency improvement • Dramatic cost reduction for DC system over existing AC • Significant improvement in reliability Sponsor - NSF Power Supply Tradeoffs – an Example • IBM eServer 900 • 30% volume taken by PS • 10% volume by cooling ROADBLOCK ! Lossy Components and Packaging! 10 kW Power Supply P. Singh, et.al., IBM J. Res. & Dev., Nov. 2002 50 kHz to 75 kHz = 50% reduction in size and 50% reduction in cooling 12 90 100 4 .) 8 85 10 2 a.u Cost (¢/W) Cost MTBF ( 4 80 (%) Efficiency 1 1 Si (a.u.) Cost Cooling 50 100 150 1 2 3 Frequency (kHz) Power Density (a.u.) Power Switching Fundamentals A A A A VSUP iL Load R L L Diode B Power D Switch C B B B Typical Loads Power Switching Circuit D RG G VGS S VGS 0 Ton T time Typical Power Switch and Control Power MOSFET Switching V SUP 2 PC = IDS RON ON-state Loss OFF-state Loss ILOAD = IDS LOAD POFF = ILKVSUP 2 PSW = CINV GSf Energy Recoverable Current Source PL = ILOADVSUP Energy IC I Supplied GS VOUT T = 1/f D VIN VGS CIN VGS Time Figure of Merit (FOM) = RONCIN; RONQGS K. Shenai, IEEE TED, vol. 37, no. 4, pp. 1141-1153, April 1990 HARD vs. SOFT Switching HARD SOFT 1000 100 1000 100 di/dt di/dt (+ ve) (+ ve) dv/dt dv/dt ZVS Turn-on (- ve) (- ve) Turn-on Voltage (V) Voltage (A) Current (V) Voltage (A) Current 5 10 15 5 10 15 Time (μsec) Time (μsec) 1000 100 1000 100 di/dt dv/dt dv/dt (+ ve) di/dt (- ve) (- ve) (+ ve) ZCS Turn-off Turn-off Voltage (V) Voltage (V) Voltage Current (A) Current (A) Current 5 10 15 5 10 15 Time (μsec) Time (μsec) Current High-End Computer Power Supply Simplify Bulky HV Driver New Power MOSFET New Power MOSFET New Power MOSFET High-End Computer Power Supply Current Industry Standard 90%, High Current 48V Bus 92%, $0.2-$0.5/W 82%, Multiple Output VRM 2kW 2.65kW 2.44kW 12V 2.95kW POL PFC BULK ISOLATED 110-220VAC 48V 12V 5V DC-DC DC-DC BUCK POL DC-DC 3.3V BUCK POL DC-DC 1.xV BUCK POL DC-DC Overall: 68% Efficient, 950W Power Loss, $1020 Cost and MTBF of ~ 200,000 Hours. Current Power System Cost, Energy Efficiency, and Reliability are Dictated by Power Semiconductor Switch Loss. More Integrated Solution New IC with Simple HV Driver New Power MOSFET New New Power SR IC MOSFET New Power MOSFET Replace with Efficient Power Switches and IC, Eliminate HV Driver Increase Overall Efficiency to 90%, Reduce Cost by 60% High-End Server Power Supply Quantum Leap in System Performance & Reliability 95%, Low Current 380V Bus 95%, Multiple Output VRM 2kW 2.2kW 2.1kW 12V POL PFC BULK 110-220VAC 12V 5V DC-DC BUCK POL DC-DC 3.3V BUCK POL DC-DC 1.xV BUCK POL DC-DC Goal: 90% Efficient, 200W Power Loss, $400 Cost and MTBF ~ 500,000 Hours. 60% Savings in System Cost 80% Savings in Power Loss Improved Field Reliability Field-Reliability Paradigm Need “End-of-Life” SOA that accounts for sustained dynamic application stresses K. Shenai, IEEE Spectrum, pp. 50-55, July 2000 Field-Failure of Power MOSFETs K. Shenai, 12th Ann. Automotive Reliability Workshop, Nashville, TN, 2007 (invited) Field MTBF Improvement – an Example Vendor K. Shenai et al., IECEC Conference, pp. 1480-1490, 2000 Monolithic Mobile Platform Digital (1–3.6 V) RF/Analog (2.5–12V) – Processor – Filters and mixers – Memory Power – VCO – RF baseband I I – LNA and opamp – Control N N – Sensors – PA T T E Digital E Physical R A/D Signal D/A R Input F Processing F Video A A Display C C E Communication E Power (1–12 V) Mixed-Signal (1.5–5 V) – Converter – DSP Electrical – Regulator – Multimedia Optical – On-chip power supply – Signal converters ● Present Solution: multiple, cascaded, independent DC-DC power converters. inefficient, narrow band PA with poor S/N performance. ● Need: Integrate DC-DC converters and broadband PA into a single power management chip; develop single-chip mobile platform. Battery and Power Management Evolution 3G’s next step B 3G E A N T E T R E G R D Y Y LI P H R M A SOC R U Power N NiMh Management V Integrated LDO Gas Smaller E LDO T Gauge Circuit S µLDO T I Dc/Dc Size M I LDO Converter High E Battery N Regulator Efficiency Lower Discrete G DC Converters Charger Noise Regulator 1990 1993 1996 2000 2002 2004 OEM Loads and SMPS Specifications 4 – 28V LDO, Hybrid DISPLAY 10 – 200mA 50% - 92% Low speed (ms) $0.3 - $3 Li-ion Cell Boost (2.7 - 4.2V) 0.4 – 3.4V LDO, Hybrid RFPA 10mA – 2A 30% - 92% Low speed (ms) $0.3 - $1.5 Boost 2.5 – 3.2V - Hybrid RADIO,FLASH 1 – 20mA 70% - 92% Medium speed $0.8 - $1.2 (ms - µs) Buck 0.8 – 2.5V Hybrid CPU,DSP 1 – 800mA 70% - 92% High speed $1 - $1.5 (µs- ns) Slow Buck Chip-Scale DC-DC Power Conversion Techniques Concept Power Range Efficiency Speed Profile Charge Pump ~ few 100 mA 70% - 90% Slow Single Chip/Hybrid Switch Capacitor ~ few 100 mA 70% - 90% Slow Single Chip/Hybrid LDO ~ several Amps 50% Slow Single Chip Note: All of the above techniques are RC time limited to a response time of several µsecs., and generally deliver very low power (few hundred mW). Switch Mode (SMPS) ~ several Amps 70% - 95% Slow Hybrid Note: To obtain high power conversion efficiency, switch-mode power conversion is performed mostly at < 3 MHz; it is slow and in hybrid circuitry form. High-Current Charge Pumps 5 • Wide input range Patents Pending - Down to 0.5 V 4 - As high as 3 V • Variable output 3 - Voltage doubling - Voltage tuning (± 5%) 2 • Performance - Over 90% efficiency OUTPUT CURRENT (A) CURRENT OUTPUT - Under 1% ripple 1 - Under 100-kHz clock • Uses standard CMOS 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 • Ideal for constant-load INPUT VOLTAGE (V) applications Cell Phone Application 2 1 PA 10 – 20% Driver 60 – 70% High Power External LDO, SMPS Hybrid SMPS Backlight Driver High Voltage Low Current 4 10 – 20% 3 Integrated LDO, SC, CP Hybrid SMPS Battery Baseband Charger (DSP, Arm, Audio Low Voltage amp, …) High Current High Speed Switch Mode (SMPS) Converter in Handheld Devices Maxim 8506-8508 in a Cell Phone Maxim 1582 in a Notebook PA Power Supply White LED Power Supply Large External Passives High-frequency (@ > 1 MHz) switch- mode power conversion facilitates on- chip integration of passive elements. Efficiency vs. Load Current – Maxim 8506-8508 used for Cell Phone RFPA power supply VIN = 2.5V 100 90 80 PWM Mode VOUT = 1.2V 70 Efficiency (%) Efficiency VOUT = 2.5V 50 1 10 100 1000 Load Current (mA) Circuit Size and Height RF PA SMPS Inductor Size: 6 x 6 X 2.0 mm Our Power Management Chip Hybrid inductor size is 10x our chip Size: 3 x 3 x .84 mm Chip Scale Power Inductor 60 nH 1.6 mm x 1.6 mm; W=40 µm, S=35 µm Q 40 500 µm air gap 35 Patents Pending |Eqn| 30 Q_sample3 300 µm air gap |Eqn| Q_sample4 25 0.1 0.2 0.3 0.4 0 Radiation Boundary on Top Surface with Air Fr equency ( GHz) Dielectric 50 μm Polyimide Tape f=_FREQ Extracted Model from HFSS Simulation.