Design for Electromagnetic Compatibility--In a Nutshell: Theory and Practice

Preface
Acknowledgments
Contents
Acronyms
Symbols and Units
1 Introduction
1.1 What Is EMC?
1.2 EMC vs. EMI
1.3 Why Is EMC Important?
1.4 EMC Terms and Definitions
1.4.1 Emission
1.4.2 Immunity
1.5 Design for EMC
1.6 Summary
References
2 Regulations and Standards
2.1 Big Picture
2.2 EMC Compliance
2.3 EMC Regulations
2.4 EMC Standards
2.4.1 What Are EMC Standards?
2.4.2 Why Do We Need EMC Standards?
2.4.3 Who Writes EMC Standards?
2.4.4 EMC Emission Standards
2.4.5 EMC Immunity Standards
2.4.6 Types of EMC Standards
2.4.6.1 Basic EMC Publications
2.4.6.2 EMC Product Standards
2.4.6.3 EMC Product Family Standards
2.4.6.4 Generic EMC Standards
2.4.7 EMC Standards in Different Industries
2.4.8 Which EMC Standards to Apply?
2.5 Compliance Marks
2.6 Global Market Access
2.7 Summary
References
3 Decibel
3.1 Gain and Loss [dB]
3.2 Absolute Levels [dBm, dBμV, dBμA]
3.3 Summary
References
4 Frequency and Wavelength
4.1 EMC and Frequencies
4.2 Wavelength vs. Frequency
4.2.1 Wavelength in Any Media
4.2.2 Wavelength in Insulating Media
4.2.3 Wavelength in Vacuum
4.2.4 Wavelength in Good Conducting Media
4.3 Wavelength of Signals Along Wires, Cables, and PCB Traces
4.3.1 Wavelength of Signals Along Blank Wires
4.3.2 Wavelength of Signals Along Cables and PCBTraces
4.3.3 Summary
References
5 Time-Domain and Frequency-Domain
5.1 Fourier Analysis
5.2 Frequency Spectra of Digital Signals
5.3 Bandwidth of Digital Signals
5.4 Ringing and Frequency Spectrum
5.5 Summary
References
6 RF Parameters
Reflection Coefficient Γ
6.2 Voltage Standing Wave Ratio (VSWR)
6.3 Return Loss (RL)
6.4 Insertion Loss (IL)
6.5 Scattering Parameters
6.6 Signal-to-Noise Ratio
6.7 Noise Factor and Noise Figure
6.8 1 dB Compression Point
6.9 Spectrum Analyzer Terms
6.9.1 Frequency Range
6.9.2 Resolution Bandwidth
6.9.3 Video Bandwidth
6.9.4 Sweep Time
6.9.5 Detectors
6.10 Summary
References
7 Transmission Lines
7.1 What Is a Transmission Line
7.2 When to Consider Transmission Lines
7.2.1 Rule of Thumb for lcritical in the Frequency Domain
7.2.2 Rule of Thumb for lcritical in the Time Domain
7.2.3 Critical Length lcritical
7.3 Characteristic Impedance Z0
7.3.1 Characteristic Impedance Z0 of Any Transmission Line
7.3.2 Characteristic Impedance Z0 of Lossless Transmission Lines
7.3.3 Characteristic Impedance Z0 of Parallel Wires
7.3.4 Characteristic Impedance Z0 of Twisted Pairs
7.3.5 Characteristic Impedance Z0 of Coaxial Cables
7.3.6 Characteristic Impedance Z0 of Microstrip Lines
7.3.7 Characteristic Impedance Z0 of Coplanar Waveguide with Reference Plane
7.3.8 Characteristic Impedance Z0 of Centered Striplines
7.4 Per-Unit-Length Inductance L' and Capacitance C'
7.4.1 L' and C' of Two-Wire Lines
7.4.2 L' and C' of Wires Above Ground Plane
7.4.3 L' and C' of Coaxial Cables
7.4.4 L' and C' of PCB Traces
7.5 Propagation Constant γ
7.6 Input Impedance of Transmission Lines
7.6.1 Input Impedance of Any Transmission Line
7.6.2 Input Impedance of a Lossless Transmission Line
7.6.3 Input Impedance of a Transmission Line At l=λ/2
7.6.4 Impedance of a Transmission Line At l=λ/4
7.6.5 Impedance of a Matched Transmission Line
7.6.6 Impedance of a Shorted Transmission Line
7.6.7 Impedance of an Open Transmission Line
7.7 High-Frequency Losses
Loss Tangent tan(δ)
7.9 Balanced vs. Unbalanced Transmission Lines
7.10 Single-Ended vs. Differential Interfaces
7.11 Summary
References
8 Electromagnetic Fields
8.1 The Electromagnetic Field
8.2 Electromagnetic Field Characteristics
8.3 Near-Field vs. Far-Field
8.3.1 Near-Field
8.3.1.1 Reactive Near-Field
8.3.1.2 Radiating Near-Field
8.3.2 Far-Field
8.4 Intrinsic Impedance η
8.4.1 Intrinsic Impedance of Any Media
8.4.2 Intrinsic Impedance of Magnetic Lossless Media
8.4.3 Intrinsic Impedance of Lossless Insulators
8.4.4 Intrinsic Impedance of Free-Space
8.4.5 Intrinsic Impedance of Good Conductors
8.5 Wave Impedance Zw
8.5.1 Wave Impedance of Any Wave
8.5.2 Wave Impedance vs. Distance
8.5.3 Wave Impedance in the Near-Field of E-FieldAntennas
8.5.4 Wave Impedance in the Near-Field of H-Field Antennas
8.5.5 Wave Impedance of Plane Waves
8.6 Summary
References
9 Antennas
9.1 Antennas and EMC Testing
9.2 Isotropic Radiator
9.3 Antenna Directivity D
9.4 Antenna Gain G
9.5 Effective Aperture Ae
9.6 Antenna Factor AF
9.7 Ground Plane Reflection and Multipath Effect
9.8 Intended Antennas
9.8.1 E-Field Antennas and Emission Testing
9.8.2 E-Field Antennas and Immunity Testing
9.8.3 H-Field Antennas and Emission Testing
9.8.4 H-Field Antennas and Immunity Testing
9.9 Unintended Antennas
9.9.1 E-Field from Differential-Mode Currents in Small Loops
9.9.2 E-Field from Common-Mode Currents in ShortCables
9.9.3 Maximum E-Field from Common-Mode Signals
9.9.3.1 Generic Calculation of Maximum E-Field
9.9.3.2 Maximum E-Field for a Given Common-Mode Current
9.9.3.3 Maximum E-Field for a Given Common-Mode Voltage
9.9.4 Maximum E-Field from PCB with Attached Cable
9.10 Free-Space Path Loss
9.11 Link Budget
9.12 Summary
References
10 Skin Effect
10.1 Skin Depth
10.2 DC vs. AC Resistance
10.3 Surface Resistance
10.4 Summary
References
11 Components
11.1 Conductors
11.1.1 Definition of a Conductor
11.1.2 Conductor Equivalent Circuits
11.1.3 Resistance of a Conductor
11.1.4 Internal Inductance of a Conductor
11.1.5 Internal Impedance of a Conductor
11.1.6 External Inductance of a Single Conductor
11.1.7 Conductor with Return Current Path
11.1.7.1 Conductor Length < (λ/10)
11.1.7.2 Conductor Length > (λ/10)
11.2 Resistors
11.3 Capacitors
11.4 Inductors
11.5 Ferrites Beads
11.5.1 Cable Mount Ferrite Beads
11.5.2 PCB Mount Ferrite Beads
11.6 Common-Mode Chokes
11.7 Baluns
11.8 Clamping Devices
11.8.1 Varistors
11.8.2 TVS Diodes
11.9 Crowbar Devices
11.10 Summary
References
12 Noise Coupling
12.1 Coupling Paths
12.1.1 Conductive Coupling
12.1.2 Capacitive Coupling
12.1.3 Inductive Coupling
12.1.4 Electromagnetic Coupling
12.2 Differential-Mode vs. Common-Mode
12.2.1 Differential-Mode vs. Common-Mode Voltage
12.2.2 Differential-Mode vs. Common-Mode Current
12.3 Differential-Mode Noise Sources
12.3.1 Conductive Coupling to Differential-Mode Noise
12.3.2 Capacitive Coupling to Differential-Mode Noise
12.3.3 Inductive Coupling to Differential-Mode Noise
12.3.4 Common-to-Differential-Mode Conversion
12.4 Common-Mode Noise Sources
12.4.1 Capacitive Coupling to Common-Mode Noise
12.4.2 Electromagnetic Coupling to Common-Mode Noise
12.4.3 Reference Point Noise to Common-Mode Noise
12.4.4 Differential-to-Common-Mode Conversion
12.5 Summary
References
13 Shielding
13.1 Shielding Theory
13.2 Shielding Effectiveness
13.3 Far-Field Shielding
13.3.1 Reflection Loss R for Far-Field Shielding
13.3.2 Absorption Loss A for Far-Field Shielding
13.3.3 Multiple-Reflection Loss Correction M for Far-Field Shielding
13.4 Near-Field Shielding
13.4.1 Near-Field Shielding of Electric Sources
13.4.2 Near-Field Shielding of Magnetic Sources
13.4.3 Low-Frequency Magnetic Field Shielding
13.5 Slots and Apertures
13.5.1 Single Aperture
13.5.2 Multiple Apertures
13.5.3 Waveguide Below Cutoff
13.6 Grounding of Shields
13.7 Cable Shields
13.7.1 Transfer Impedance Zt
13.7.2 Cable Shielding Against Capacitive Coupling
13.7.3 Cable Shielding Against Inductive Coupling
13.7.4 Grounding of Cable Shields
13.8 Summary
References
14 Grounding
14.1 Types of Ground
14.2 Ground Symbols
14.3 EMC Grounding Philosophy
14.4 Return Current Path on PCB Ground Planes
14.5 Grounding of Systems
14.5.1 Single-Point Ground Systems
14.5.2 Multipoint Ground Systems
14.5.3 Hybrid Ground Systems
14.6 Ground Loops
14.7 Summary
References
15 Filtering
15.1 Filter Characterization
15.1.1 Time-Domain: Step Response
15.1.2 Frequency-Domain: Frequency Response
15.2 Low-Pass Filters
15.3 High-Pass Filters
15.4 Band-Pass Filters
15.5 Band-Stop Filters
15.6 Active and Passive Filters
15.7 Differential- and Common-Mode Filters
15.7.1 Differential-Mode Filters
15.7.2 Common-Mode Filters
15.8 Mains Supply Filters
15.9 Transient Suppression Filters
15.10 Digital Filters
15.11 Summary
References
16 EMC Design Guidelines
16.1 Most Common EMC Issues in Practice
16.2 Guideline # 1: Never Route Signals Over Split ReferencePlanes
16.3 Guideline # 2: Always Consider the Return Current
16.4 Guideline # 3: Decoupling—Use Low-Inductance Capacitors AND Planes
16.5 Guideline # 4: Use Ground Planes on PCB for Shielding
16.6 Guideline # 5: Route High-Frequency Signals Adjacent to a Plane
16.7 Guideline # 6: Control Rise- and Fall-Time
16.8 Guideline # 7: Keep Clock lines As Short As Possible
16.9 Guideline # 8: Fill Top and Bottom Layers with Circuit GND
16.10 Guideline # 9: Add Stitching Vias Around High-Speed Signal Vias
16.11 Guideline # 10: Add a Capacitor Close to Every Pin of a Connector
16.12 Guideline # 11: Connect Circuit GND to Chassis at IO Area
16.13 Guideline # 12: Lay Cables Along Chassis (GND/Earth)
16.14 Guideline # 13: Don't Use Cable Shield as Signal Conductor for Low-Frequency Signals
16.15 Guideline # 14: Cable Shield Grounding on Only One End for Low-Frequency Signals
16.16 Guideline # 15: Cable Shield Grounding on Both Ends for High-Frequency Signals
16.17 Guideline # 16: Minimize Loop Area of Signals in Cables
16.18 Guideline # 17: Avoid Electrical Balance Changes
References
A Constants
B Complex Numbers
B.1 Definition and Notation
B.2 Cartesian Complex Plane
B.3 Polar Complex Plane
B.4 Complex Conjugate
B.5 Mathematical Operations with Complex Numbers
B.6 Impedances in the Complex Plane
C Vectors
C.1 Vector Definition
C.2 Sum of Vectors
C.3 Vector Multiplication with Scalars
C.4 Vector Dot Product
C.5 Vector Cross Product
References
D Electromagnetism
D.1 Voltage
D.2 Current
D.3 Impedance
D.4 Power
D.5 Complex Permittivity
D.6 Complex Permeability
D.7 Electric Field
D.8 Electric Flux
D.9 Electric Flux Density
D.10 Displacement Current Density
D.11 Polarization Density
D.12 Electric Current Density
D.13 Magnetic Field
D.14 Magnetic Flux
D.15 Magnetic Flux Density
D.16 Electromagnetic Field
References
E Maxwell's Equations and Lorentz's Force Law
E.1 Gauss' Law for Electricity
E.2 Gauss' Law for Magnetism
E.3 Faraday's Law
E.4 Ampére's Law
E.5 Lorentz's Force Law
Reference
F Integral Transforms
F.1 Fourier Series
F.2 Fourier Transform
F.3 Discrete Fourier Transform (DFT)
F.4 Discrete-Time Fourier Transform (DTFT)
F.5 Laplace Transform
F.6 Z-Transform
References
G Material Properties
G.1 Conductor Properties
G.2 Insulator Properties
G.3 PCB Materials
References
H Galvanic Series
H.1 Corrosion
H.2 Corrosion Prevention
H.3 Standard Electrode Potential Series
H.4 Seawater Galvanic Series
References
I Triboelectric Effect
I.1 How Electrostatic Charges Are Produced
I.2 Triboelectric Series
References
J Country-Specific EMC Regulations
J.1 Australia and New Zealand
J.2 Brazil
J.3 Canada
J.4 China
J.5 Eurasian Economic Union
J.6 European Union
J.7 India
J.8 Japan
J.9 Republic of Korea
J.10 Switzerland
J.11 Taiwan
J.12 Turkey
J.13 United Kingdom
J.14 United States of America
References
K EMC Test Setups and Equipment
K.1 Pre-compliance vs. Compliance Testing
K.2 RF Emission: CISPR 11
K.2.1 CISPR 11: Applicability
K.2.2 CISPR 11: Group 1, 2
K.2.3 CISPR 11: Class A, B
K.2.4 CISPR 11: Test Setup
K.2.5 CISPR 11: Test Limits
K.2.5.1 CISPR 11: Test Limits at Test Site
K.2.5.2 CISPR 11: Test Limits In Situ
K.3 RF Emission: CISPR 32
K.3.1 CISPR 32: Applicability
K.3.2 CISPR 32: Class A, B
K.3.3 CISPR 32: Limits
K.4 Harmonic Currents: IEC 61000-3-2
K.4.1 IEC 61000-3-2: Applicability
K.4.2 IEC 61000-3-2: Class A, B, C, D
K.4.3 IEC 61000-3-2: Test Setup
K.4.4 IEC 61000-3-2: Limits
K.5 Flicker: IEC 61000-3-3
K.5.1 IEC 61000-3-3: Applicability
K.5.2 IEC 61000-3-3: Test Setup
K.5.3 IEC 61000-3-3: Limits
K.6 ESD: IEC 61000-4-2
K.6.1 IEC 61000-4-2: Test Setup
K.6.2 IEC 61000-4-2: Test Levels
K.7 RF Radiated Immunity: IEC 61000-4-3
K.7.1 IEC 61000-4-3: Test Setup
K.7.2 IEC 61000-4-3: Test Levels
K.8 EFT: IEC 61000-4-4
K.8.1 IEC 61000-4-4: Test Setup
K.8.2 IEC 61000-4-4: Test Levels
K.9 Surge: IEC 61000-4-5
K.9.1 IEC 61000-4-5: Test Setup
K.9.2 IEC 61000-4-5: Test Levels
K.10 RF Conducted Immunity: IEC 61000-4-6
K.10.1 IEC 61000-4-6: Test Setup
K.10.2 IEC 61000-4-6: Test Levels
K.11 Magnetic Field Immunity: IEC 61000-4-8
K.11.1 IEC 61000-4-8: Applicability
K.11.2 IEC 61000-4-8: Test Setup
K.11.3 IEC 61000-4-8: Test Levels
K.12 AC Dips: IEC 61000-4-11
K.12.1 IEC 61000-4-11: Applicability
K.12.2 IEC 61000-4-11: Test Setup
K.12.3 IEC 61000-4-11: Test Levels
K.13 Generic Immunity Levels for Residential Environments: IEC 61000-6-1
K.14 Generic Immunity Levels for Industrial Environment: IEC 61000-6-2
K.15 Generic Emission Limits for Residential Environments: IEC 61000-6-3
K.16 Generic Emission Limits for Industrial Environment: IEC 61000-6-4
K.17 Generic Emission Limits for Light-Industrial Environment: IEC 61000-6-8
References
L American Wire Gauge (AWG)
M Rules of Thumb
M.1 Air Breakdown Voltage
M.2 Amplitude of Square Wave Harmonics
M.3 Antenna Input Power for Desired E-Field Strength
M.4 Bandwidth of Digital Signals
M.5 Critical Length of Transmission Lines
M.6 Characteristic Impedance of Wires
M.7 Capacitance Per-Unit-Length
M.8 Inductance Per-Unit-Length
M.9 CMOS Input Impedance
M.10 E-Field from Differential-Mode Currents in Small Loops
M.11 E-Field from Common-Mode Currents in Short Cables
M.12 E-Field from Common-Mode Current with Cable atResonance
M.13 E-Field from Common-Mode Voltage with Cable atResonance
M.14 E-Field Strength for Given Antenna Power
M.15 Galvanic Corrosion
M.16 Return Current on PCB Planes
M.17 Via Capacitance and Inductance
References
Index