DOCSLIB.ORG

Advances in Class-I C0G MLCC and SMD Film Capacitors

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Advances in Class-I C0G MLCC and SMD Film Capacitors Advances in Class-I C0G MLCC and SMD Film Capacitors Xilin Xu, Matti Niskala*, Abhijit Gurav, Mark Laps, Kimmo Saarinen*, Aziz Tajuddin, Davide Montanari**, Francesco Bergamaschi**, and Evangelista Boni** KEMET Electronics Corporation, 2835 KEMET Way, Simpsonville, SC 29681 Tel: +01-864-963-6307, Fax: +01-864-963-6492, e-mail: [email protected] * SMD products, Evox Rifa Group Oyj, a Kemet Company Lars Sonckin kaari 16, 02600 Espoo, Finland Tel: + 358 50 3873205, Fax: + 358 50 83873205, e-mail: [email protected] ** SMD Products, Arcotronics Group, a Kemet Company via San Lorenzo 19, 40037 Sasso Marconi (Bologna), Italy Tel: +39 51 939 220, Fax: +39 51 939 324, e-mail: [email protected] ABSTRACT For applications requiring low dielectric losses (or low DF), low acoustic noise (no piezoelectric effect) and good temperature stability of capacitance, the top two choices are Class-I C0G MLCC and SMD film capacitors. There have been recent advances in both C0G MLCCs and SMD film capacitors. The C0G MLCCs have benefited from base metal electrodes (BME) in combination with an improved ability to stack well over 400 layers in the MLCC, and have resulted in cost effective and volumetrically efficient ratings up to 1 μF. The SMD film capacitors have seen significant advances in capacitance and voltage extensions, as well as heat resistance under lead-free soldering conditions. This paper will discuss the technical basis for advances in each of these technologies and give some guidance on the optimum areas (capacitance, size, voltage) for the application of each technology. INTRODUCTION In applications where capacitance needs to be precisely controlled over a wide temperature range with low dielectric losses or low acoustic noise, thru-hole film capacitors have been the optimum choice. These applications include digital tuning and high fidelity audio devices. Furthermore, the new Microsoft operating system - Windows Vista has strict audio-performance requirements to enhance the desktop and laptop PC audio quality and fidelity. Thus, hardware manufactures have to meet these requirements in circuit design and component selections in order to license the Windows Vista logo [1]. More recently, higher capacitance ceramic capacitors with a C0G dielectric and surface mount (SMD) film capacitors have become available. This paper describes the technological advances that have produced those solutions and gives some guidance on which solution should be selected. The Electronic Industry Association (EIA) specification for C0G dielectric, also known as NP0 (“negative-positive- zero”), is that the capacitance variation from room temperature (25°C) should be within 0 ± 30 ppm/°C (or ΔCMax/C ≤ 0.3%) over the temperature range of -55°C to 125°C. The C0G dielectrics are usually non-ferroelectric materials, and exhibit linear response to voltage and temperature. Compared with Class-II dielectrics, typically X7R/X5R materials, C0G dielectrics have the advantages of high stability of capacitance over temperature and voltage, no aging, no microphonics, as well as a low dielectric loss. However, in the past, maximum capacitance values have been limited due to thick dielectric layers, and costs have been relatively high due to the use of precious metal electrodes (PME). This paper describes the advances that have allowed the use of thinner dielectric layers and the replacement of PME with base metal electrodes (BME) that allow the ceramic C0G dielectric capacitors to have competitive capacitances with film capacitors over a range of case sizes and voltages. ©2008 ECA (Electronics Components, Assemblies & Materials Association), Arlington, VA Proceedings CARTS USA 2008, 28th Symposium for Passive Electronics, March, Newport Beach, CA Typical plastic dielectrics for film capacitors include polypropylene (PP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulphide (PPS), and more rarely polytetrafluoroethylene (PTFE) and polyacrylic. Thermal stability requirements for surface mounting are more stringent than for thru-hole, and PP dielectric cannot meet the requirements. While PTFE meets the thermal stability requirements, it is expensive and not easily metallized, so it is only used in specialized applications. The typical plastic materials for SMD film capacitors are PET, PEN, and PPS. This paper describes the advances that have been made in order to make film capacitors based on these dielectrics resistant not only to surface mount reflow conditions, but to the very demanding reflow conditions required for Pb-free surface mounting. EXPERIMENTAL The capacitance was measured on a HP-4284A Precision LCR meter at 1 kHz and 1 Vrms. Insulation resistance (IR), temperature coefficient of capacitance (TCC), and voltage coefficient of capacitance (VCC) were measured in a Saunders & Associates 4220A temperature test chamber. The reliability of MLCCs was characterized by highly accelerated life test (HALT), in which the acceleration is accomplished by temperature and voltage stresses. The HALT test was performed at 175°C and 400 Volts for 46 hours. A sample size of 40 pieces was used for each sample. HALT time-to-failure (TTF) was recorded when IR at test temperature dropped below 3.78 MΩ. In order to evaluate the electrical noise generated from a capacitor, a test setup was required to generate a constant mechanical shock to the capacitor while monitoring the electrical noise generated from the shock. To generate the mechanical shock, the capacitor was mounted to an FR4 PCB measuring 1”x1”x0.03” and then mounted to a fixture to hold the board in place. A rod was fabricated and dropped on the PCB directly adjacent to the capacitor from a constant height. Dropping the rod on the PCB generated sufficient energy to the board to create electrical noise in the capacitor. To monitor the amount of shock delivered to the capacitor, an accelerometer was mounted on the board directly below the capacitor. The accelerometer readings were registered on a multi-channel oscilloscope. Alone, an electrically noisy capacitor will not generate enough noise to be detectable on an oscilloscope. When these capacitors are used in the input stage of an amplifier, their induced electrical noise can be amplified and delivered to the output of the amplifier. It is therefore necessary to replicate this scenario by connecting the capacitor samples to the input stage of an amplifier and monitoring its output on an oscilloscope. For this setup, two wires connected the FR4 PCB to the footprint where the capacitor would be mounted in the amplifier. When the test sample is given a mechanical shock, the electrical noise will run through the input stage and then will be amplified to the output. The signal is then put through a differential amplifier with a 20dB gain. The output from the differential amplifier is analyzed on the oscilloscope. A schematic of this measurement setup is shown in Fig. 1. Capacitor samples made from BME C0G, standard X7R, PET, PEN, and PPS material with the same capacitance of 0.22 μF were tested. Oscilloscope Differential Amplifier Signal Conditioner DUT Shock Point Amplifier Accelerometer Fig. 1. Setup for measuring electrical noise performance. ©2008 ECA (Electronics Components, Assemblies & Materials Association), Arlington, VA Proceedings CARTS USA 2008, 28th Symposium for Passive Electronics, March, Newport Beach, CA DISCUSSION (1) Advances in C0G MLCCs Traditional C0G dielectric materials are mainly based on the barium neodymium titanate (BNT) and compatible with PME, such as Pd or Ag/Pd. To provide a more cost effective solution, the MLCC manufacturers have mostly converted from PME to BME (mainly Ni). The BME C0G dielectrics are mainly CaZrO3-based materials. BNT has a dielectric constant (k) of around 70, while the k of CaZrO3-based materials is around 30. Intuitively, we would expect that less capacitance in a given case size would result from the switch from BNT to CaZrO3-based materials. However, we are able to use much thinner layers of CaZrO3-based materials compared to BNT, and remarkably still obtain higher insulation resistance (IR) and higher reliability at a given voltage. This breakthrough has led to higher capacitance, lower cost, and robust MLCCs with C0G dielectrics [2, 3]. A comparison of the maximum capacitance offering for BME C0G with PME C0G by case size is shown in Fig. 2. Three voltage ratings, 25V, 50V, and 100V are compared. It is clear to see that the BME C0G can offer at least an order of magnitude higher capacitance than PME C0G in the same case size and same voltage rating. For example, for 25Vdc rated 1206 case size, the maximum capacitance offering of BME C0G is 100 nF, while PME C0G can only offer 10 nF capacitance. This plot also indicates that at the same capacitance and same voltage rating, the BME C0G MLCC has a much smaller case size than PME C0G MLCC, or much higher volumetric efficiency. 1000 PME 25V C0G BME 25V C0G PME 50V C0G BME 50V C0G 100 PME 100V C0G BME 100V C0G 10 Max. CAP (nF) Max. CAP 1 0.1 0402 0603 0805 1206 1210 Case Size (EIA) Fig. 2. PME C0G vs. BME C0G: maximum capacitance offering. The reason why at the same case size and same voltage rating, BME C0G can offer much higher capacitance than PME is because of its thin, but high reliability dielectric layers. For example, the HALT reliability of two 1206 case size 103 (10nF) capacitance samples (one is PME C0G and the other is BME C0G) is shown in Fig. 3. These two samples both passed the required QA life test, which was performed at 125°C and twice rated voltage for 1000 hours. In order to make these parts fail, the HALT test was conducted at an extreme severe environment, which was at 175°C and 400V. Figure 3 shows that the BME1206-103 sample exhibits markedly longer time-to-failure (TTF) values compared to the PME1206-103. The median time-to-failure (MTTF) at HALT for PME1206-103 was 62.6 minutes, while for BME1206-103 was 869.6 minutes, more than an order of magnitude improvement in MTTF.
Load more

Recommended publications
  • Dielectric Permittivity Model for Polymer–Filler Composite Materials by the Example of Ni- and Graphite-Filled Composites for High-Frequency Absorbing Coatings
    coatings Article Dielectric Permittivity Model for Polymer–Filler Composite Materials by the Example of Ni- and Graphite-Filled Composites for High-Frequency Absorbing Coatings Artem Prokopchuk 1,*, Ivan Zozulia 1,*, Yurii Didenko 2 , Dmytro Tatarchuk 2 , Henning Heuer 1,3 and Yuriy Poplavko 2 1 Institute of Electronic Packaging Technology, Technische Universität Dresden, 01069 Dresden, Germany; [email protected] 2 Department of Microelectronics, National Technical University of Ukraine, 03056 Kiev, Ukraine; [email protected] (Y.D.); [email protected] (D.T.); [email protected] (Y.P.) 3 Department of Systems for Testing and Analysis, Fraunhofer Institute for Ceramic Technologies and Systems IKTS, 01109 Dresden, Germany * Correspondence: [email protected] (A.P.); [email protected] (I.Z.); Tel.: +49-3514-633-6426 (A.P. & I.Z.) Abstract: The suppression of unnecessary radio-electronic noise and the protection of electronic devices from electromagnetic interference by the use of pliable highly microwave radiation absorbing composite materials based on polymers or rubbers filled with conductive and magnetic fillers have been proposed. Since the working frequency bands of electronic devices and systems are rapidly expanding up to the millimeter wave range, the capabilities of absorbing and shielding composites should be evaluated for increasing operating frequency. The point is that the absorption capacity of conductive and magnetic fillers essentially decreases as the frequency increases. Therefore, this Citation: Prokopchuk, A.; Zozulia, I.; paper is devoted to the absorbing capabilities of composites filled with high-loss dielectric fillers, in Didenko, Y.; Tatarchuk, D.; Heuer, H.; which absorption significantly increases as frequency rises, and it is possible to achieve the maximum Poplavko, Y.
    [Show full text]
  • Modeling Dielectric Absorption in Capacitors
    The Designer’s Guide Community downloaded from www.designers-guide.org Modeling Dielectric Absorption in Capacitors Ken Kundert Designer’s Guide Consulting, Inc. Version 2e, August 2021 It is well known that dielectric absorption plays a critical role in determining the accu- racy of analog sampled-data systems that are based on charge storage, such as sample- and-holds and switched-capacitor ADCs. Less appreciated, but no less important, is the role it plays in determining the quality factor, or Q, of the capacitor. Dielectric absorp- tion has both storage and loss components that act, and are significant, over the entire usable frequency range of the capacitor. Along with background information on the origins of dielectric absorption, this paper presents two models for a capacitor that exhibits dielectric absorption. The first is the relatively well known model proposed by Dow. The second is a model with relatively little exposure that is based on the dielectric permittivity model of Cole and Cole. This model has fewer parameters than the Dow model and is predictive over a very broad range of frequencies. This manuscript was originally written in March 1982 and was revised in October 2001. It was last updated on August 18, 2021. You can find the most recent version at www.designers- guide.org. Contact the author via e-mail at [email protected]. Permission to make copies, either paper or electronic, of this work for personal or classroom use is granted without fee provided that the copies are not made or distributed for profit or commer- cial advantage and that the copies are complete and unmodified.
    [Show full text]
  • Review of Technologies and Materials Used in High-Voltage Film Capacitors
    polymers Review Review of Technologies and Materials Used in High-Voltage Film Capacitors Olatoundji Georges Gnonhoue 1,*, Amanda Velazquez-Salazar 1 , Éric David 1 and Ioana Preda 2 1 Department of Mechanical Engineering, École de technologie supérieure, Montreal, QC H3C 1K3, Canada; [email protected] (A.V.-S.); [email protected] (É.D.) 2 Energy Institute—HEIA Fribourg, University of Applied Sciences of Western Switzerland, 3960 Sierre, Switzerland; [email protected] * Correspondence: [email protected] Abstract: High-voltage capacitors are key components for circuit breakers and monitoring and protection devices, and are important elements used to improve the efficiency and reliability of the grid. Different technologies are used in high-voltage capacitor manufacturing process, and at all stages of this process polymeric films must be used, along with an encapsulating material, which can be either liquid, solid or gaseous. These materials play major roles in the lifespan and reliability of components. In this paper, we present a review of the different technologies used to manufacture high-voltage capacitors, as well as the different materials used in fabricating high-voltage film capacitors, with a view to establishing a bibliographic database that will allow a comparison of the different technologies Keywords: high-voltage capacitors; resin; dielectric film Citation: Gnonhoue, O.G.; Velazquez-Salazar, A.; David, É.; Preda, I. Review of Technologies and 1. Introduction Materials Used in High-Voltage Film High-voltage films capacitors are important components for networks and various Capacitors. Polymers 2021, 13, 766. electrical devices. They are used to transport and distribute high-voltage electrical energy https://doi.org/10.3390/ either for voltage distribution, coupling or capacitive voltage dividers; in electrical sub- polym13050766 stations, circuit breakers, monitoring and protection devices; as well as to improve grid efficiency and reliability.
    [Show full text]
  • Basic PCB Material Electrical and Thermal Properties for Design Introduction
    1 Basic PCB material electrical and thermal properties for design Introduction: In order to design PCBs intelligently it becomes important to understand, among other things, the electrical properties of the board material. This brief paper is an attempt to outline these key properties and offer some descriptions of these parameters. Parameters: The basic ( and almost indispensable) parameters for PCB materials are listed below and further described in the treatment that follows. dk, laminate dielectric constant df, dissipation factor Dielectric loss Conductor loss Thermal effects Frequency performance dk: Use the design dk value which is assumed to be more pertinent to design. Determines such things as impedances and the physical dimensions of microstrip circuits. A reasonable accurate practical formula for the effective dielectric constant derived from the dielectric constant of the material is: -1/2 εeff = [ ( εr +1)/2] + [ ( εr -1)/2][1+ (12.h/W)] Here h = thickness of PCB material W = width of the trace εeff = effective dielectric constant εr = dielectric constant of pcb material df: The dissipation factor (df) is a measure of loss-rate of energy of a mode of oscillation in a dissipative system. It is the reciprocal of quality factor Q, which represents the Signal Processing Group Inc., technical memorandum. Website: http://www.signalpro.biz. Signal Processing Gtroup Inc., designs, develops and manufactures analog and wireless ASICs and modules using state of the art semiconductor, PCB and packaging technologies. For a free no obligation quote on your product please send your requirements to us via email at [email protected] or through the Contact item on the website.
    [Show full text]
  • Agilent Basics of Measuring the Dielectric Properties of Materials
    Agilent Basics of Measuring the Dielectric Properties of Materials Application Note Contents Introduction ..............................................................................................3 Dielectric theory .....................................................................................4 Dielectric Constant............................................................................4 Permeability........................................................................................7 Electromagnetic propagation .................................................................8 Dielectric mechanisms ........................................................................10 Orientation (dipolar) polarization ................................................11 Electronic and atomic polarization ..............................................11 Relaxation time ................................................................................12 Debye Relation .................................................................................12 Cole-Cole diagram............................................................................13 Ionic conductivity ............................................................................13 Interfacial or space charge polarization..................................... 14 Measurement Systems .........................................................................15 Network analyzers ..........................................................................15 Impedance analyzers and LCR meters.........................................16
    [Show full text]
  • Microphonics & Lorentz Detuning: Determined by Cavity/Cryomodule Design and Background Environment
    Old Dominion University October 2012 2 2 2 f opt (b 1) fo IRQQ(/) where b oocos V Phase Amplitude Controller Controller Klystron 1.0 Limiter 0.9 0.8 Loop 0.7 Phase Amplitude 0.6 CEBAF 6 GeV Set Point 0.5 Amplitude CEBAF Upgrade Detector 0.4 Cavity 0.3 0.2 Energy Content (Normalized)Content Energy 0.1 Reference Phase 0.0 Phase -1,000 -800 -600 -400 -200 0 200 Set Point Detector Detuning (Hz) • RF Systems • What are you controlling? • Cavity Equations • Control Systems Cavity Models • Algorithms Generator Driven Resonator (GDR) Self Excited Loop (SEL) • Hardware Receiver ADC/Jitter Transmitter Digital Signal Processing • Cavity Tuning & Resonance Control Stepper Motor Piezo • RF Systems are broken RF Control Power down into two parts. Electronics Amplifier • The high power section consisting of the power amplifier and the high power transmission line Waveguide/ (waveguide or coax) Coax • The Low power (level) section (LLRF) consisting of the field and resonance control components Cavity • Think your grandfathers “Hi-Fi” stereo or your guitar amp. • Intensity modulation of DC beam by control grid • Efficiency ~ 50-70% (dependent on operation Triode Tetrode mode) • Gain 10-20 dB • Frequency dc – 500 MHz • Power to 1 MW • Velocity modulation with input Cavity • Drift space and several cavities to achieve bunching • It is highly efficient DC to RF Conversion (50%+) • High gain >50 dB • CW klystrons typically have a modulating anode for - Gain control - RF drive power in saturation • Power: CW 1 MW, Pulsed 5 MW • Frequencies 300 MHz to 10 GHz+ A. Nassiri CW SCRF workshop 2012 • Intensity modulation of DC beam by control grid • It is highly efficient DC to RF Conversion approaching 70% • Unfortunately low gain 22 dB (max) • Power: CW to 80 kW • Frequencies 300 MHz to 1.5 GHz As a tetrode As a klystron A.
    [Show full text]
  • Application Note: ESR Losses in Ceramic Capacitors by Richard Fiore, Director of RF Applications Engineering American Technical Ceramics
    Application Note: ESR Losses In Ceramic Capacitors by Richard Fiore, Director of RF Applications Engineering American Technical Ceramics AMERICAN TECHNICAL CERAMICS ATC North America ATC Europe ATC Asia [email protected] [email protected] [email protected] www.atceramics.com ATC 001-923 Rev. D; 4/07 ESR LOSSES IN CERAMIC CAPACITORS In the world of RF ceramic chip capacitors, Equivalent Series Resistance (ESR) is often considered to be the single most important parameter in selecting the product to fit the application. ESR, typically expressed in milliohms, is the summation of all losses resulting from dielectric (Rsd) and metal elements (Rsm) of the capacitor, (ESR = Rsd+Rsm). Assessing how these losses affect circuit performance is essential when utilizing ceramic capacitors in virtually all RF designs. Advantage of Low Loss RF Capacitors Ceramics capacitors utilized in MRI imaging coils must exhibit Selecting low loss (ultra low ESR) chip capacitors is an important ultra low loss. These capacitors are used in conjunction with an consideration for virtually all RF circuit designs. Some examples of MRI coil in a tuned circuit configuration. Since the signals being the advantages are listed below for several application types. detected by an MRI scanner are extremely small, the losses of the Extended battery life is possible when using low loss capacitors in coil circuit must be kept very low, usually in the order of a few applications such as source bypassing and drain coupling in the milliohms. Excessive ESR losses will degrade the resolution of the final power amplifier stage of a handheld portable transmitter image unless steps are taken to reduce these losses.
    [Show full text]
  • Dielectric Loss
    Dielectric Loss - εr is static dielectric constant (result of polarization under dc conditions). Under ac conditions, the dielectric constant is different from the above as energy losses have to be taken into account. - Thermal agitation tries to randomize the dipole orientations. Hence dipole moments cannot react instantaneously to changes in the applied field Æ losses. - The absorption of electrical energy by a dielectric material that is subjected to an alternating electric field is termed dielectric loss. - In general, the dielectric constant εr is a complex number given by where, εr’ is the real part and εr’’ is the imaginary part. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Consider parallel plate capacitor with lossy dielectric - Impedance of the circuit - Thus, admittance (Y=1/Z) given by Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - The admittance can be written in the form The admittance of the dielectric medium is equivalent to a parallel combination of - Note: compared to parallel an ideal lossless capacitor C’ with a resistance formula. relative permittivity εr’ and a resistance of 1/Gp or conductance Gp. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Input power: - Real part εr’ represents the relative permittivity (static dielectric contribution) in capacitance calculation; imaginary part εr’’ represents the energy loss in dielectric medium. - Loss tangent: defined as represents how lossy the material is for ac signals. Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss The dielectric loss per unit volume: Dept of ECE, National University of Singapore Chunxiang Zhu Dielectric Loss - Note that the power loss is a function of ω, E and tanδ.
    [Show full text]
  • A Hybrid PV-Battery/Supercapacitor System and a Basic Active Power Control Proposal in MATLAB/Simulink
    electronics Article A Hybrid PV-Battery/Supercapacitor System and a Basic Active Power Control Proposal in MATLAB/Simulink Mustafa Ergin ¸Sahin 1,* and Frede Blaabjerg 2 1 Department of Electrical and Electronics Engineering, Recep Tayyip Erdo˘ganUniversity, 53100 Rize, Turkey 2 Department of Energy Technology, Aalborg University, Pontoppidantstraede, 9220 Aalborg East, Denmark; [email protected] * Correspondence: [email protected] Received: 30 October 2019; Accepted: 3 January 2020; Published: 9 January 2020 Abstract: An increase in the integration of renewable energy generation worldwide brings along some challenges to energy systems. Energy systems need to be regulated following grid codes for the grid stability and efficiency of renewable energy utilization. The main problems that are on the active side can be caused by excessive power generation or unregulated energy generation, such as a partially cloudy day. The main problems on the load side can be caused by excessive or unregulated energy demand or nonlinear loads which deteriorate the power quality of the energy networks. This study focuses on the energy generation side as active power control. In this study, the benefits of supercapacitor use in a hybrid storage system are investigated and analyzed. A hybrid system in which photovoltaic powered and stored the energy in battery and supercapacitor are proposed in this study to solving the main problems in two sides. The supercapacitor model, photovoltaic model, and the proposed hybrid system are designed in MATLAB/Simulink for 6 kW rated power. Also, a new topology is proposed to increase the energy storage with supercapacitors for a passive storage system. The instantaneous peak currents energy is aimed to store in supercapacitors temporarily with this topology.
    [Show full text]
  • A Comprehensive Guide to Selecting the Right Capacitor for Your Specific Application
    CAPACITOR FUNDAMENTALS EBOOK A Comprehensive Guide to Selecting the Right Capacitor for Your Specific Application 2777 Hwy 20 (315) 655-8710 [email protected] Cazenovia, NY 13035 knowlescapacitors.com CAPACITOR FUNDAMENTALS EBOOK TABLE OF CONTENTS Introduction .................................. 2 The Key Principles of Capacitance and How a Basic Capacitor Works .............................. 3 How Capacitors are Most Frequently Used in Electronic Circuits ............................. 6 Factors Affecting Capacitance .................. 9 Defining Dielectric Polarization .................. 11 Dielectric Properties ........................... 15 Characteristics of Ferroelectric Ceramics ......................... 19 Characteristics of Linear Dielectrics .............. 22 Dielectric Classification ......................... 24 Test Parameters and Electrical Properties .......... 27 Industry Test Standards Overview. 32 High Reliability Testing .......................... 34 Visual Standards For Chip Capacitors ............. 37 Chip Attachment and Termination Guidelines ...... 42 Dissipation Factor and Capacitive Reactance ..... 49 Selecting the Right Capacitor for Your Specific Application Needs ............................ 51 1 CAPACITOR FUNDAMENTALS EBOOK INTRODUCTION At Knowles Precision Devices, our expertise in capacitor technology helps developers working on some of the world’s most demanding applications across the medical device, military and aerospace, telecommunications, and automotive industries. Thus, we brought together our top engineers
    [Show full text]
  • MT-101: Decoupling Techniques
    MT-101 TUTORIAL Decoupling Techniques WHAT IS PROPER DECOUPLING AND WHY IS IT NECESSARY? Most ICs suffer performance degradation of some type if there is ripple and/or noise on the power supply pins. A digital IC will incur a reduction in its noise margin and a possible increase in clock jitter. For high performance digital ICs, such as microprocessors and FPGAs, the specified tolerance on the supply (±5%, for example) includes the sum of the dc error, ripple, and noise. The digital device will meet specifications if this voltage remains within the tolerance. The traditional way to specify the sensitivity of an analog IC to power supply variations is the power supply rejection ratio (PSRR). For an amplifier, PSRR is the ratio of the change in output voltage to the change in power supply voltage, expressed as a ratio (PSRR) or in dB (PSR). PSRR can be referred to the output (RTO) or referred to the input (RTI). The RTI value is equal to the RTO value divided by the gain of the amplifier. Figure 1 shows how the PSR of a typical high performance amplifier (AD8099) degrades with frequency at approximately 6 dB/octave (20 dB/decade). Curves are shown for both the positive and negative supply. Although 90 dB at dc, the PSR drops rapidly at higher frequencies where more and more unwanted energy on the power line will couple to the output directly. Therefore, it is necessary to keep this high frequency energy from entering the chip in the first place. This is generally done with a combination of electrolytic capacitors (for low frequency decoupling), ceramic capacitors (for high frequency decoupling), and possibly ferrite beads.
    [Show full text]
  • New Polymer Dielectric for High Energy Density Film Capacitors
    New Polymer Dielectric For High Energy Density Film Capacitors Paul Winsor, IV and Edward Lobo CDE 167 John Vertente Blv. New Bedford, MA 02745 Tel.: 508-994-9661 Fax: 508-995-3000 [email protected] [email protected] M. Zafar A. Munshi and Ayad Ibrahim Lithium Power Technolgies, Inc. 20955 Morris Avenue Manvel, TX 77578-3819 Tel.: 281-489-4889 Fax: 281-489-6644 [email protected] Abstract A new dielectric film has been developed that greatly increases the energy density capability of plastic film capacitors. This film has been developed over the past four years by a consortium consisting of Lithium Power Technologies, CDE Corp., Dupont Teijin Films (DTF), Case Western Reserve University, and Ohio Aerospace Institute in an Advanced Technology Program funded by the Department of Commerce. We are now entering the commercialization stage of this project. Plastic film capacitors have been the capacitor of choice for many power electronics, power conditioning, and pulse power applications such as motors, lighting and portable defibrillators because of their low dissipation factor (DF), excellent high-frequency response, high insulation resistance (IR), self-healing ability, and high-voltage capabilities. Existing capacitor technologies now present a barrier to achieving significant packaging (size and weight) reductions and struggle to meet new market-driven performance requirements. These markets not only include hybrid electric vehicles, wind power and portable defibrillators, but also the military and aerospace markets where the power source must be incredibly lightweight. Ultra thin gauge biaxially oriented films produced by DTF in thicknesses of 1.4 to 4 microns and thicker were constructed into metallized capacitors ranging from 1 to 140 microFarads.
    [Show full text]