DOCSLIB.ORG

Printed Circuit Board Decoupling

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Printed Circuit Board Decoupling Printed Circuit Board Decoupling Todd H. Hubing Michelin Professor of Vehicular Electronics Clemson University The Concept of Power Bus Decoupling L P V inductance V V board V supply inductance L G Power Supply Printed Circuit Board T. Hubing October 2006 2 The Concept of Power Bus Decoupling L P V V board supply L G Power Supply Printed Circuit Board T. Hubing October 2006 3 The Concept of Power Bus Decoupling L L trace trace C Cd d C L L b d d L L trace trace T. Hubing October 2006 4 Why is this a problem? Signal Integrity is compromised! Power Bus Noise Radiated and Conducted EMI! T. Hubing October 2006 5 Why is this a problem? For some ICs, the high-frequency currents drawn from the power pins can be much greater than the high-frequency currents in the signals! T. Hubing October 2006 6 Has anybody studied this? B. Rubin and W. D. Becker, “The Modeling of Delta-I Noise in High Performance Computer Modules,” Conference Record of the 17th Asilomar Conference on Circuits, Systems, and Computers, IEEE Cat. # 83CH1939-8, Oct. 31-Nov. 2, 1983. H. W. Ott, Noise Reduction Techniques in Electronic Systems, 2nd Ed., John Wiley Interscience, New York, 1988. N. Raver et al., “Circuit Noise Study,” Proceedings of the technical program for NEPCON WEST 92, Anaheim Convention Center, Anaheim CA, pp. 77-86, Feb. 23-27, 1992. R. Downing, P. Gebler, G. Katopis, “Decoupling Capacitor Effects on Switching Noise,” Conference Record of the IEEE Topical Meeting on Electrical Performance of Electronic Packaging, IEEE Cat. # 92TH0452-5, Apr. 22-24, 1992. A. R. Djordjevic and T. K. Sarkar, “An Investigation of Delta-I Noise on Integrated Circuits,” IEEE Trans. on Electromagnetic Compat., vol. 35, no. 2, May 1993. J. Sisler, “Eliminating Capacitors From Multilayer PCBs,” Printed Circuit Design, July 1991. C. Dirks, “Wideband Supply Voltage Decoupling for Integrated Circuits,” EMC Test & Design, November/December, 1992. T. Wang, “Characteristics of Buried Capacitance,” EMC Test & Design, February 1993. A lot of people have been looking at the power bus S. Daijavad and H. Heeb, “On the Effectiveness of Decouplingnoise Capacitors problem in Reducing for a EM long Radiation time. from PCBs,” Proc. Of the IEEE EMC Symposium, Atlanta, GA, August 1995. T. H. Hubing, J. L. Drewniak, T. P. Van Doren, and D. Hockanson, “Power Bus Decoupling on Multilayer Printed Circuit Boards,” IEEE Transactions on Electromagnetic Compatibility, vol. EMC-37, no. 2, May 1995, pp. 155-166. H. Shi, F. Sha, J. L. Drewniak, T. H. Hubing, T. P. Van Doren, and F. Yuan, "Simulation and Measurement for Decoupling on Multilayer PCB DC Power Buses," Proceedings of the 1996 IEEE International Symposium on Electromagnetic Compatibility, Santa Clara, CA, August 1996, pp. 430-435. John R. Barnes’ Bibliography has 837 entries. T. Hubing October 2006 7 Conflicting Rules for PCB Decoupling Use small-valued capacitors for high-frequency decoupling. Locate capacitors near the Use 0.01 μF for local decoupling! power pins of active Use capacitors with a low ESR! devices. μ Avoid capacitors with a low Use 0.001 F for local decoupling! ESR! Locate capacitors near the Run traces from device to capacitor, ground pins of active then to power planes. devices. Location of decoupling Never put traces on capacitors is not relevant. decoupling capacitors. Use the largest valued Local decoupling capacitors should have a capacitors you can find range of values from 100 pF to 1 μF! in a given package size. T. Hubing October 2006 8 Main Questions How much capacitance do I need? Where should it be located? How should it be connected? T. Hubing October 2006 9 Conflicting Goals? Do we want a low-impedance power bus that can supply lots of current without a significant change in voltage? Do we want a high-impedance power bus that isolates each device from other devices? T. Hubing October 2006 10 How much capacitance do you need? ZSUPPLY + + V − −NOISE = VNOISE ZSUPPLY IDEVICE T. Hubing October 2006 11 How much capacitance do you need? L P V Zsupply board Vsupply LG Power Supply Printed Circuit Board V (f ) Z (f ) = NOISEMAX max I (f ) Lsource DEVICEMAX Z supply π + 2 f (LP LG ) 1 = Zmax 2πf0C Z 1 max C = min π 2 f0 Zmax = 1 2 (2πf0 ) L Z source f = max 0 π 2 Lsource T. Hubing October 2006 12 How much capacitance do you need? Impedance approach Ltrace Ltrace C V (f ) b Z (f ) = NOISEMAX max Ltrace Ltrace IDEVICEMAX(f ) 1 1 = Z π π 2πf C max 2 f1C 2 fLtrace 0 1 C = Zmax min π 2 f0 Zmax = 1 π 2 (2 f0 ) Lsource f0 f1 T. Hubing October 2006 13 How much capacitance do you need? Capacitance Ratio approach Recognizing that CMOS loads are capacitances, we are simply using decoupling capacitors to charge load capacitances. Total decoupling capacitance is set to a value that is equal to the total device capacitance times the power bus voltage divided by the maximum power bus noise. T. Hubing October 2006 14 How much capacitance do you need? Guidelines approach Let’s do it the way that worked for somebody at sometime in the past. “… include one 0.01 uF local decoupling capacitor for each VCC pin of every active component on the board plus 1 bulk decoupling capacitor with a value equal to 5 times the sum of the local decoupling capacitance.” . T. Hubing October 2006 15 Main Questions How much capacitance do I need? Where should it be located? How should it be connected? T. Hubing October 2006 16 Printed Circuit Board Decoupling Strategies T. Hubing October 2006 17 Boards without Power Planes C Cd d C b OK? T. Hubing October 2006 18 Boards without Power Planes C Cd d C b Got a ground plane? T. Hubing October 2006 19 Presentation to Johnson Controls October 2006 20 Presentation to Johnson Controls October 2006 21 Boards without Power Planes The effectiveness of a single capacitor as a filter is limited by mutual inductance. Input Output T. Hubing October 2006 22 Boards without Power Planes Filter Comparison 0 -10 A -20 -30 B dB -40 21 S -50 10 nF cap (1 via) 10 nF cap (3 vias) -60 2x 4.7nF caps, one via 2x 4.7nF caps, two vias -70 -80 5 6 7 8 9 10 10 10 10 10 Frequency (Hz) Two capacitors can be much more effective than one. T. Hubing October 2006 23 Power Bus Decoupling Strategy With no power plane ¾ layout low-inductance power distribution ¾ size bulk decoupling to meet board requirements ¾ size local decoupling to meet device requirements ¾ two caps can be much better than one ¾ avoid resonances by minimizing L References: T. Hubing, “Printed Circuit Board Power Bus Decoupling,” LG Journal of Production Engineering, vol. 3, no. 12, December 2000, pp. 17-20. (Korean language publication) . T. Zeeff, T. Hubing, T. Van Doren and D. Pommerenke, “Analysis of simple two-capacitor low-pass filters,” IEEE Transactions on Electromagnetic Compatibility, vol. 45, no. 4, Nov. 2003, pp. 595-601. T. Hubing October 2006 24 Boards with Closely Spaced Power Planes Cb C Cd d Power Distribution Model ~ (5 - 500 MHz) Board with power and ground planes T. Hubing October 2006 25 Boards with Closely Spaced Power Planes L BULK = 5 nH L D = 2nH CB = 3.4 nF CBULK = 1 μ F C D = 10nF Bare Board 100. 10. Board with decoupling 1. 0.1 0.1 MHz 1 MHz 10 MHz 100 MHz 1 GHz T. Hubing October 2006 26 For Boards with “Closely-Spaced” Planes The location of the decoupling capacitors is not critical. The value of the local decoupling capacitors is not critical, but it must be greater than the interplane capacitance. The inductance of the connection is the most important parameter of a local decoupling capacitor. None of the local decoupling capacitors are effective above a couple hundred megahertz. None of the local decoupling capacitors are supplying significant charge in the first few nanoseconds of a transition. T. Hubing October 2006 27 Presentation to Johnson Controls October 2006 28 Inductance of connections to planes On boards with closely spaced power and ground planes: Generally speaking, 100 decoupling capacitors connected through 1 nH of inductance will be as effective as 500 decoupling capacitors connected through 5 nH of inductance. 5 nH 0.5 nH T. Hubing October 2006 29 Power Bus Decoupling Strategy With closely spaced (<.25 mm) planes ¾ size bulk decoupling to meet board requirements ¾ size local decoupling to meet board requirements ¾ mount local decoupling in most convenient locations ¾ don’t put traces on capacitor pads ¾ too much capacitance is ok ¾ too much inductance is not ok References: T. H. Hubing, J. L. Drewniak, T. P. Van Doren, and D. Hockanson, “Power Bus Decoupling on Multilayer Printed Circuit Boards,” IEEE Transactions on Electromagnetic Compatibility, vol. EMC-37, no. 2, May 1995, pp. 155-166. T. Zeeff and T. Hubing, “Reducing power bus impedance at resonance with lossy components,” IEEE Transactions on Advanced Packaging, vol. 25, no. 2, May 2002, pp. 307-310. M. Xu, T. Hubing, J. Chen, T. Van Doren, J. Drewniak and R. DuBroff, “Power bus decoupling with embedded capacitance in printed circuit board design,” IEEE Transactions on Electromagnetic Compatibility, vol. 45, no. 1, Feb. 2003, pp. 22-30. T. Hubing October 2006 30 Boards with Power Planes Spaced >0.5 mm Cb C Cd d T. Hubing October 2006 31 4-Layer Board Measurements T. Hubing October 2006 32 4-Layer Board Measurements T. Hubing October 2006 33 Boards with Power Planes Spaced >0.5 mm M L L L L TRACE VIA VIA TRACE PORT 1 PORT 2 C BOARD DECOUPLING ACTIVE DEVICE CAPACITOR SIGNAL PLANE POWER PLANE LOOP A LOOP A and LOOP B GROUND PLANE SIGNAL PLANE On boards with a spacing between power and ground planes of ~30 mils (0.75 mm) or more, the inductance of the planes can no longer be neglected.
Load more

Recommended publications
  • Run Capacitor Info-98582
    Run Cap Quiz-98582_Layout 1 4/16/15 10:26 AM Page 1 ® Run Capacitor Info WHAT IS A CAPACITOR? Very simply, a capacitor is a device that stores and discharges electrons. While you may hear capacitors referred to by a variety of names (condenser, run, start, oil, etc.) all capacitors are comprised of two or more metallic plates separated by an insulating material called a dielectric. PLATE 1 PLATE 2 A very simple capacitor can be made with two plates separated by a dielectric, in this PLATE 1 PLATE 2 case air, and connected to a source of DC current, a battery. Electrons will flow away from plate 1 and collect on plate 2, leaving it with an abundance of electrons, or a “charge”. Since current from a battery only flows one way, the capacitor plate will stay BATTERY + – charged this way unless something causes current flow. If we were to short across the plates with a screwdriver, the resulting spark would indicate the electrons “jumping” from plate 2 to plate 1 in an attempt to equalize. As soon as the screwdriver is removed, plate 2 will again collect a PLATE 1 PLATE 2 charge. + BATTERY – Now let’s connect our simple capacitor to a source of AC current and in series with the windings of an electric motor. Since AC current alternates, first one PLATE 1 PLATE 2 MOTOR plate, then the other would be charged and discharged in turn. First plate 1 is charged, then as the current reverses, a rush of electrons flow from plate 1 to plate 2 through the motor windings.
    [Show full text]
  • Switched-Capacitor Circuits
    Switched-Capacitor Circuits David Johns and Ken Martin University of Toronto ([email protected]) ([email protected]) University of Toronto 1 of 60 © D. Johns, K. Martin, 1997 Basic Building Blocks Opamps • Ideal opamps usually assumed. • Important non-idealities — dc gain: sets the accuracy of charge transfer, hence, transfer-function accuracy. — unity-gain freq, phase margin & slew-rate: sets the max clocking frequency. A general rule is that unity-gain freq should be 5 times (or more) higher than the clock-freq. — dc offset: Can create dc offset at output. Circuit techniques to combat this which also reduce 1/f noise. University of Toronto 2 of 60 © D. Johns, K. Martin, 1997 Basic Building Blocks Double-Poly Capacitors metal C1 metal poly1 Cp1 thin oxide bottom plate C1 poly2 Cp2 thick oxide C p1 Cp2 (substrate - ac ground) cross-section view equivalent circuit • Substantial parasitics with large bottom plate capacitance (20 percent of C1) • Also, metal-metal capacitors are used but have even larger parasitic capacitances. University of Toronto 3 of 60 © D. Johns, K. Martin, 1997 Basic Building Blocks Switches I I Symbol n-channel v1 v2 v1 v2 I transmission I I gate v1 v p-channel v 2 1 v2 I • Mosfet switches are good switches. — off-resistance near G: range — on-resistance in 100: to 5k: range (depends on transistor sizing) • However, have non-linear parasitic capacitances. University of Toronto 4 of 60 © D. Johns, K. Martin, 1997 Basic Building Blocks Non-Overlapping Clocks I1 T Von I I1 Voff n – 2 n – 1 n n + 1 tTe delay 1 I fs { --- delay V 2 T on I Voff 2 n – 32e n – 12e n + 12e tTe • Non-overlapping clocks — both clocks are never on at same time • Needed to ensure charge is not inadvertently lost.
    [Show full text]
  • Development of Printed Circuit Board Technology Embedding Active and Passive Devices for E-Function Module
    Development of Printed Circuit Board Technology Embedding Active and Passive Devices for e-Function Module Noboru Fujimaki Kiyoshi Koike Kazuhiro Takami Sigeyuki Ogata Hiroshi Iinaga Background shortening of signal wirings between circuits, reduction of damping resistors and elimination of characteristic Higher functionality of today’s portable devices impedance controls. Embedded component module demands smaller, lighter and thinner electronic boards have been adopted for higher functionality of components. Looking at the evolution of package video cameras and miniaturizing wireless communication miniaturization from the flat structure (System in Package: devices. It is expected the use will spread to a wider SiP) -> silicon chip stack structure (Chip on Chip: CoC) -> range of areas including automotive, consumer products, package stack structure (Package on Package: PoP) -> Si industrial equipment and infrastructure equipment. To through chip contact structure, the technology has gone meet these needs, a technology to package and embed from two-dimensional to three-dimensional packaging the various components and LSI will be required. This achieving high density packages. The trends in printed article discusses the method of embedding components, circuit boards and their packaging are shown in Figure 1. soldering technology, production method, reliability and Among the printed circuit boards, the three-dimensional case examples of the embedded component module integrated printed circuit board (hereafter referred to as board. “embedded component module board”) is attracting great attention. Integrating components into embedded component module boards Component embedding enables passive components (1) Embedding active components to be positioned directly beneath the LSI mounted There are two methods of embedding active on the surface providing electrical benefits such as components.
    [Show full text]
  • Utilising Commercially Fabricated Printed Circuit Boards As an Electrochemical Biosensing Platform
    micromachines Article Utilising Commercially Fabricated Printed Circuit Boards as an Electrochemical Biosensing Platform Uroš Zupanˇciˇc,Joshua Rainbow , Pedro Estrela and Despina Moschou * Centre for Biosensors, Bioelectronics and Biodevices (C3Bio), Department of Electronic & Electrical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, UK; [email protected] (U.Z.); [email protected] (J.R.); [email protected] (P.E.) * Correspondence: [email protected]; Tel.: +44-(0)-1225-383245 Abstract: Printed circuit boards (PCBs) offer a promising platform for the development of electronics- assisted biomedical diagnostic sensors and microsystems. The long-standing industrial basis offers distinctive advantages for cost-effective, reproducible, and easily integrated sample-in-answer-out diagnostic microsystems. Nonetheless, the commercial techniques used in the fabrication of PCBs produce various contaminants potentially degrading severely their stability and repeatability in electrochemical sensing applications. Herein, we analyse for the first time such critical technological considerations, allowing the exploitation of commercial PCB platforms as reliable electrochemical sensing platforms. The presented electrochemical and physical characterisation data reveal clear evidence of both organic and inorganic sensing electrode surface contaminants, which can be removed using various pre-cleaning techniques. We demonstrate that, following such pre-treatment rules, PCB-based electrodes can be reliably fabricated for sensitive electrochemical
    [Show full text]
  • Best Practices for Board Layout of Motor Drivers
    Application Report SLVA959A–November 2018–Revised January 2019 Best Practices for Board Layout of Motor Drivers .................................................................................................................. Motor Drive Business Unit ABSTRACT PCB design of motor drive systems is not trivial and requires special considerations and techniques to achieve the best performance. Power efficiency, high-speed switching frequency, low-noise jitter, and compact board design are few primary factors that designers must consider when laying out a motor drive system. Texas Instruments' DRV devices are ideal for such type of systems because they are highly integrated and well-equipped with protection circuitry. The goal of this application report is to highlight the primary factors of a motor drive layout when using a DRV device and provide a best practice guideline for a high performance solution that reduces thermal stress, optimizes efficiency, and minimizes noise in a motor drive application. Contents 1 Grounding Optimization ..................................................................................................... 3 2 Thermal Overview ........................................................................................................... 7 3 Vias........................................................................................................................... 11 4 General Routing Techniques ............................................................................................. 14 5 Bulk and Bypass
    [Show full text]
  • Kirchhoff's Laws in Dynamic Circuits
    Kirchhoff’s Laws in Dynamic Circuits Dynamic circuits are circuits that contain capacitors and inductors. Later we will learn to analyze some dynamic circuits by writing and solving differential equations. In these notes, we consider some simpler examples that can be solved using only Kirchhoff’s laws and the element equations of the capacitor and the inductor. Example 1: Consider this circuit Additionally, we are given the following representations of the voltage source voltage and one of the resistor voltages: ⎧⎧10 V fortt<< 0 2 V for 0 vvs ==⎨⎨and 1 −5t ⎩⎩20 V forte>+ 0 8 4 V fort> 0 We wish to express the capacitor current, i 2 , as a function of time, t. Plan: First, apply Kirchhoff’s voltage law (KVL) to the loop consisting of the source, resistor R1 and the capacitor to determine the capacitor voltage, v 2 , as a function of time, t. Next, use the element equation of the capacitor to determine the capacitor current as a function of time, t. Solution: Apply Kirchhoff’s voltage law (KVL) to the loop consisting of the source, resistor R1 and the capacitor to write ⎧ 8 V fort < 0 vvv12+−=ss0 ⇒ v2 =−= vv 1⎨ −5t ⎩16− 8et V for> 0 Use the element equation of the capacitor to write ⎧ 0 A fort < 0 dv22 dv ⎪ ⎧ 0 A fort < 0 iC2 ==0.025 =⎨⎨d −5t =−5t dt dt ⎪0.025() 16−> 8et for 0 ⎩1et A for> 0 ⎩ dt 1 Example 2: Consider this circuit where the resistor currents are given by ⎧⎧0.8 A fortt<< 0 0 A for 0 ii13==⎨⎨−−22ttand ⎩⎩0.8et−> 0.8 A for 0 −0.8 e A fort> 0 Express the inductor voltage, v 2 , as a function of time, t.
    [Show full text]
  • Capacitive Voltage Transformers: Transient Overreach Concerns and Solutions for Distance Relaying
    Capacitive Voltage Transformers: Transient Overreach Concerns and Solutions for Distance Relaying Daqing Hou and Jeff Roberts Schweitzer Engineering Laboratories, Inc. Revised edition released October 2010 Previously presented at the 1996 Canadian Conference on Electrical and Computer Engineering, May 1996, 50th Annual Georgia Tech Protective Relaying Conference, May 1996, and 49th Annual Conference for Protective Relay Engineers, April 1996 Previous revised edition released July 2000 Originally presented at the 22nd Annual Western Protective Relay Conference, October 1995 CAPACITIVE VOLTAGE TRANSFORMERS: TRANSIENT OVERREACH CONCERNS AND SOLUTIONS FOR DISTANCE RELAYING Daqing Hou and Jeff Roberts Schweitzer Engineering Laboratories, Inc. Pullman, W A USA ABSTRACT Capacitive Voltage Transformers (CVTs) are common in high-voltage transmission line applications. These same applications require fast, yet secure protection. However, as the requirement for faster protective relays grows, so does the concern over the poor transient response of some CVTs for certain system conditions. Solid-state and microprocessor relays can respond to a CVT transient due to their high operating speed and iflCreased sensitivity .This paper discusses CVT models whose purpose is to identify which major CVT components contribute to the CVT transient. Some surprises include a recom- mendation for CVT burden and the type offerroresonant-suppression circuit that gives the least CVT transient. This paper also reviews how the System Impedance Ratio (SIR) affects the CVT transient response. The higher the SIR, the worse the CVT transient for a given CVT . Finally, this paper discusses improvements in relaying logic. The new method of detecting CVT transients is more precise than past detection methods and does not penalize distance protection speed for close-in faults.
    [Show full text]
  • MAT 253 Operating Manual - Rev
    MAT 253 OPERATING MANUAL Issue 04/2002 Ident. No. 114 9090 Thermo Finnigan MAT GmbH Postfach 1401 62 28088 Bremen Germany Reparatur-Begleitkarte*) Repair-Covering Letter Absender: Geräte-Type: Despachter: Instrument Type: __________________________________ _________________________________ __________________________________ Service-Nr.: Service No Sie erhalten zur Reparatur unter unserer Bestell-Nr.: You receive for repair under our order no.: Festgestellte Mängel oder deren Auswirkung: Established defect or its effect: Bitte detaillierte Angaben machen / Please specify in detail Ein Austauschteil haben wir erhalten unter Kommissions-Nr.: An exchange part already received with commission no.: Ja/Yes Nein/No Die Anlage ist außer Funktion The system is out of function Ja/Yes Nein/No Durch die nachfolgende Unterschrift By signing this document I am/ we are certifying bestätige(n) ich /wir, daß die o.g. Teile frei von that the a. m. parts are free from hazardous gesundheitsschädlichen Stoffen sind, bzw. vor materials. In case the parts have been used for ihrer Einsendung an Thermo Finnigan MAT the analysis of hazardous substances I/we dekontaminiert wurden, falls die Teile mit attest that the parts have been decontaminated giftigen Stoffen in Verbindung gekommen sind. before sending them to Thermo Finnigan MAT. __________________________________ _________________________________ Datum / date Unterschrift / signature *) Bitte vollständig ausfüllen / Please fill in completely MAT 253 O P E R A T I N G M A N U A L TABLE OF CONTENTS 1 GETTING
    [Show full text]
  • Aluminum Electrolytic Vs. Polymer – Two Technologies – Various Opportunities
    Aluminum Electrolytic vs. Polymer – Two Technologies – Various Opportunities By Pierre Lohrber BU Manager Capacitors Wurth Electronics @APEC 2017 2017 WE eiCap @ APEC PSMA 1 Agenda Electrical Parameter Technology Comparison Application 2017 WE eiCap @ APEC PSMA 2 ESR – How to Calculate? ESR – Equivalent Series Resistance ESR causes heat generation within the capacitor when AC ripple is applied to the capacitor Maximum ESR is normally specified @ 120Hz or 100kHz, @20°C ESR can be calculated like below: ͕ͨ͢ 1 1 ͍̿͌ Ɣ Ɣ ͕ͨ͢ ∗ ͒ ͒ Ɣ Ɣ 2 ∗ ∗ ͚ ∗ ̽ 2 ∗ ∗ ͚ ∗ ̽ ! ∗ ̽ 2017 WE eiCap @ APEC PSMA 3 ESR – Temperature Characteristics Electrolytic Polymer Ta Polymer Al Ceramics 2017 WE eiCap @ APEC PSMA 4 Electrolytic Conductivity Aluminum Electrolytic – Caused by the liquid electrolyte the conductance response is deeply affected – Rated up to 0.04 S/cm Aluminum Polymer – Solid Polymer pushes the conductance response to much higher limits – Rated up to 4 S/cm 2017 WE eiCap @ APEC PSMA 5 Electrical Values – Who’s Best in Class? Aluminum Electrolytic ESR approx. 85m Ω Tantalum Polymer Ripple Current rating approx. ESR approx. 200m Ω 630mA Ripple Current rating approx. 1,900mA Aluminum Polymer ESR approx. 11m Ω Ripple Current rating approx. 5,500mA 2017 WE eiCap @ APEC PSMA 6 Ripple Current >> Temperature Rise Ripple current is the AC component of an applied source (SMPS) Ripple current causes heat inside the capacitor due to the dielectric losses Caused by the changing field strength and the current flow through the capacitor 2017 WE eiCap @ APEC PSMA 7 Impedance Z ͦ 1 ͔ Ɣ ͍̿͌ ͦ + (͒ −͒ )ͦ Ɣ ͍̿͌ ͦ + 2 ∗ ∗ ͚ ∗ ͍̿͆ − 2 ∗ ∗ ͚ ∗ ̽ 2017 WE eiCap @ APEC PSMA 8 Impedance Z Impedance over frequency added with ESR ratio 2017 WE eiCap @ APEC PSMA 9 Impedance @ High Frequencies Aluminum Polymer Capacitors have excellent high frequency characteristics ESR value is ultra low compared to Electrolytic’s and Tantalum’s within 100KHz~1MHz E.g.
    [Show full text]
  • Measurement Error Estimation for Capacitive Voltage Transformer by Insulation Parameters
    Article Measurement Error Estimation for Capacitive Voltage Transformer by Insulation Parameters Bin Chen 1, Lin Du 1,*, Kun Liu 2, Xianshun Chen 2, Fuzhou Zhang 2 and Feng Yang 1 1 State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China; [email protected] (B.C.); [email protected] (F.Y.) 2 Sichuan Electric Power Corporation Metering Center of State Grid, Chengdu 610045, China; [email protected] (K.L.); [email protected] (X.C.); [email protected] (F.Z.) * Correspondence: [email protected]; Tel.: +86-138-9606-1868 Academic Editor: K.T. Chau Received: 01 February 2017; Accepted: 08 March 2017; Published: 13 March 2017 Abstract: Measurement errors of a capacitive voltage transformer (CVT) are relevant to its equivalent parameters for which its capacitive divider contributes the most. In daily operation, dielectric aging, moisture, dielectric breakdown, etc., it will exert mixing effects on a capacitive divider’s insulation characteristics, leading to fluctuation in equivalent parameters which result in the measurement error. This paper proposes an equivalent circuit model to represent a CVT which incorporates insulation characteristics of a capacitive divider. After software simulation and laboratory experiments, the relationship between measurement errors and insulation parameters is obtained. It indicates that variation of insulation parameters in a CVT will cause a reasonable measurement error. From field tests and calculation, equivalent capacitance mainly affects magnitude error, while dielectric loss mainly affects phase error. As capacitance changes 0.2%, magnitude error can reach −0.2%. As dielectric loss factor changes 0.2%, phase error can reach 5′.
    [Show full text]
  • Series Catalog
    Conductive Polymer Aluminum Electrolytic Capacitors Surface Mount Type CY,SY series ［Guaranteed at 85 ℃］ Features ● Endurance 85 ℃ 2000 h ● Product height (3.0 mm max.) ● High ripple current (5100 mA rms to 6300 mA rms max.) ● RoHS compliance, Halogen free Specifications Series CY / SY Category temp. range –55 ℃ to +85 ℃ Rated voltage range 4.0 V, 6.3V Nominal cap. range 330 μF to 470 μF Capacitance tolerance ±20 % (120 Hz / +20 ℃) DC leakage current I ≦ 0.1 CV (μA) 2 minutes Dissipation factor (tan δ) ≦ 0.06 (120 Hz / + 20 ℃) Surge voltage (V) Rated voltage × 1.25 (15 ℃ to 35 ℃) +85 ℃ 2000 h, rated voltage applied Capacitance change Within ±20 % of the initial value Endurance Dissipation factor (tan δ) ≦ 2 times of the initial limit DC leakage current ≦ 3 times of the initial limit +60 ℃, 90 % RH, 500 h, No-applied voltage Capacitance change of 4.0 V 6.3 V Damp heat initial measurd value +60 %, –20 % +50 %, –20 % (Steady state) Dissipation factor (tan δ) ≦ 2 times of the initial limit DC leakage current Within the initial limit Marking Dimensions (not to scale) Capacitance (μF） Polarity bar (Positive) ⊖ ⊕ H P P L W1 W2 Lot No. W2 R. voltage code R. voltage code Unit：V 単位：ｍｍ g 4.0 Series L±0.2 W1±0.2 W2±0.1 H±0.2 P±0.3 j 6.3 CY / SY 7.3 4.3 2.4 2.8 1.3 ✽ Externals of figure are the reference. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use.
    [Show full text]
  • Surface Mount Ceramic Capacitor Products
    Surface Mount Ceramic Capacitor Products 082621-1 IMPORTANT INFORMATION/DISCLAIMER All product specifications, statements, information and data (collectively, the “Information”) in this datasheet or made available on the website are subject to change. The customer is responsible for checking and verifying the extent to which the Information contained in this publication is applicable to an order at the time the order is placed. All Information given herein is believed to be accurate and reliable, but it is presented without guarantee, warranty, or responsibility of any kind, expressed or implied. Statements of suitability for certain applications are based on AVX’s knowledge of typical operating conditions for such applications, but are not intended to constitute and AVX specifically disclaims any warranty concerning suitability for a specific customer application or use. ANY USE OF PRODUCT OUTSIDE OF SPECIFICATIONS OR ANY STORAGE OR INSTALLATION INCONSISTENT WITH PRODUCT GUIDANCE VOIDS ANY WARRANTY. The Information is intended for use only by customers who have the requisite experience and capability to determine the correct products for their application. Any technical advice inferred from this Information or otherwise provided by AVX with reference to the use of AVX’s products is given without regard, and AVX assumes no obligation or liability for the advice given or results obtained. Although AVX designs and manufactures its products to the most stringent quality and safety standards, given the current state of the art, isolated component failures may still occur. Accordingly, customer applications which require a high degree of reliability or safety should employ suitable designs or other safeguards (such as installation of protective circuitry or redundancies) in order to ensure that the failure of an electrical component does not result in a risk of personal injury or property damage.
    [Show full text]