272 Pages 148 B/W Illustrations
    by CRC Press

    272 Pages 148 B/W Illustrations
    by CRC Press

    With today’s electrical and electronics systems requiring increased levels of performance and reliability, the design of robust EMI filters plays a critical role in EMC compliance. Using a mix of practical methods and theoretical analysis, EMI Filter Design, Third Edition presents both a hands-on and academic approach to the design of EMI filters and the selection of components values. The design approaches covered include matrix methods using table data and the use of Fourier analysis, Laplace transforms, and transfer function realization of LC structures. This edition has been fully revised and updated with additional topics and more streamlined content.

    New to the Third Edition

    • Analysis techniques necessary for passive filter realization
    • Matrix method and transfer function analysis approaches for LC filter structure design
    • A more hands-on look at EMI filters and the overall design process

    Through this bestselling book’s proven design methodology and practical application of formal techniques, readers learn how to develop simple filter solutions. The authors examine the causes of common- and differential-mode noise and methods of elimination, the source and load impedances for various types of input power interfaces, and the load impedance aspect of EMI filter design. After covering EMI filter structures, topologies, and components, they provide insight into the sizing of components and protection from voltage transients, discuss issues that compromise filter performance, and present a goal for a filter design objective. The text also includes a matrix method for filter design, explains the transfer function method of LC structures and their equivalent polynomials, and gives a circuit design example and analysis techniques. The final chapter presents packaging solutions of EMI filters.

    EMI Filters
    Technical Challenges
    Types of EMI Filters
    No Such Thing as Black Magic
    It Is All in the Mathematics

    Why Call EMI Filters Black Magic?
    What Is EMI?
    Regular Filters versus EMI Filters
    Specifications: Real or Imagined
    The Inductive Input for the 220-A Test Method
    The 400-Hz Filter Compared with the 50- or 60-Hz Filter

    Common Mode and Differential Mode: Definition, Cause, and Elimination
    Definition of Common and Differential Modes
    The Origin of Common-Mode Noise
    Generation of Common-Mode Noise—Load
    Elimination of Common-Mode Noise—Line and Load
    Generation of Differential-Mode Noise?
    Three-Phase Virtual Ground

    EMI Filter Source Impedance of Various Power Lines
    Skin Effect
    Applying Transmission Line Concepts and Impedances
    Applying Transmission Line Impedances to Differential and Common Mode
    Differences among Power Line Measurements
    Simple Methods of Measuring AC and DC Power Lines
    Other Source Impedances

    The Various AC Load Impedances
    The Resistive Load
    Off-Line Regulator with Capacitive Load
    Off-Line Regulator with an Inductor ahead of the Storage Capacitor
    The Power Factor Correction Circuit
    Transformer Load
    The UPS Load

    DC Circuit—Load and Source
    Various Source Impedance
    Switcher Load
    DC Circuit for EMI Solutions or Recommendations
    Some Ideas for the Initial Power Supply
    Other Parts of the System
    Lossy Components
    Radiated Emissions

    Typical EMI Filters—Pros and Cons
    The π Filter
    The T Filter
    The L Filter
    The Typical Commercial Filter
    The Cauer Filter
    The RC Shunt
    The Conventional Filters

    Filter Components—the Capacitor
    Capacitor Specifications
    Capacitor Construction and Self-Resonant Frequency
    Veeing the Capacitor
    Margins, Creepage, and Corona—Split Foil for High Voltage
    Capacitor Design—Wrap-and-Fill Type

    Filter Components—the Inductor
    Inductor Styles and Specifications
    Core Types
    High-Current Inductors
    Inductor Design
    Converting from Unbalanced to Balanced

    Common-Mode Components
    The Capacitor to Ground
    Virtual Ground
    Z for Zorro
    Common-Mode Inductor
    Common-Mode Calculation
    Differential Inductance from a Common-Mode Inductor
    Common-Mode Currents—Do They All Balance?

    The Transformer’s Addition to the EMI Filter
    Transformer Advantages
    Leakage Current
    Common Mode
    Voltage Translation—Step Up or Down
    The Transformer as a Key Component of the EMI Package
    Skin Effect

    Electromagnetic Pulse and Voltage Transients
    Unidirectional versus Bidirectional
    The Three Theories
    Initial High-Voltage Inductor
    The Arrester Location
    How to Calculate the Arrester
    The Gas Tube

    What Will Compromise the Filter?
    Power Supplies—Either as Source or Load
    9- and 15-Phase Autotransformers
    Neutral Wire Not Part of the Common-Mode Inductor
    Two or More Filters in Cascade—the Unknown Capacitor
    Poor Filter Grounding
    The "Floating" Filter
    The Unknown Capacitor in the Following Equipment
    Filter Input and Output Too Close Together

    Waves as Noise Sources
    The Spike
    The Pulse
    The Power Spectrum—dB μA/MHz
    MIL-STD-461 Curve

    Initial Filter Design Requirements
    Differential-Mode Design Goals
    The Differential-Mode Filter Input Impedance
    The Differential-Mode Filter Output Impedance
    The Input and Output Impedance for a DC Filter
    Common-Mode Design Goals
    Estimation of the Common-Mode Source Impedance
    Methods of Reducing the Inductor Value due to High Current

    Matrices, Transfer Functions, and Insertion Loss
    Synthesis, Modeling, and Analysis
    Review of the A Matrix
    Transfer Functions
    Review of Matrix Topologies
    The π Filter
    The L Matrix
    The T Filter
    The Cauer or Elliptic Matrix
    The RC Shunt
    Filter Applications and Thoughts
    Single-Phase AC Filter
    Three-Phase Filters
    Low-Current Wye
    High-Current Wye
    The Single Insert
    The Low-Current Delta
    High-Current Delta
    Telephone and Data Filters
    Pulse Requirements—How to Pass the Pulse
    The DC-DC Filter
    Low-Current Filters

    Matrix Applications: A Continuation of Chapter 16
    The Impedance of the Source and Load
    dB Loss Calculations of a Single π Filter
    Example of the Calculations for a Single π Filter
    Double π Filter: Equations and dB Loss
    Triple π Filter: Equations and dB Loss

    Network Analysis of Passive LC Structures
    Lossless Networks
    Network Impedances Using Z Parameters
    Network Admittances Using Y Parameters
    Transfer Function Analysis—H(jω)
    Transfer Function Analysis—H(s)
    Coefficient-Matching Technique
    EMI Filter Stability

    Filter Design Techniques and Design Examples
    Filter Design Requirements
    Design Techniques
    Filter Design Summary
    EMI Filter Design Example
    Four-Pole LC Structure

    Packaging Information
    The Layout
    Estimated Volume
    Volume-to-Weight Ratio
    Potting Compounds

    Appendix A: K Values of Different Topologies
    Appendix B: LC Passive Filter Design
    Appendix C: Conversion Factors



    Richard Lee Ozenbaugh is a consultant of EMI filter design and magnetics engineering for such companies as Hughes Aircraft Corporation, Parker Hannifin Aerospace, Franklin Electric, McDonnell Douglas, and Cirrus Logic. Involved in the electrical and electronics industries since the early 1950s, he has worked as a radar specialist for the U.S. Navy as well as an engineer for Hopkins Engineering and RFI Corporation.

    Timothy M. Pullen is a principal electrical engineer at Rockwell Collins. He has over 25 years of experience in the research, design, and development of electronic systems for commercial and military applications, including power electronics, motor control, and full authority digital engine control technology. His areas of expertise include model-based design and control, analog circuit design, and filter design.

    "This 3rd edition book is an excellent resource for solving EMI problems. It provides a systematic procedure for identifying noise sources and provides the design tools needed to solve problems. It will be an invaluable reference book for working electrical engineers as well as students who want to learn about EMI filtering and EMI noise problems. ... The book is filled with design equations that can be immediately put to use by the reader. This book can be a guidebook for diagnosing troublesome EMI issues in existing designs, and it can also be used to prevent EMI issues from occurring in the first place because of the information in this book. ... This is a book that should be used by every electrical engineer involved with EMI issues. It is filled with design equations, but more importantly it will provide you with an understanding of EMI issues, thus, making you a better design engineer."
    —John J. Shea, IEEE Electrical Insulation Magazine, March/April, Vol. 29, No.2, 2013