Preface xiii
About the Companion Website xv
1 Frequency Spectra of Digital Signals 1
1.1 EMC Units 1
1.1.1 Logarithm and Decibel Definition 1
1.1.2 Power and Voltage (Current) Gain in dB 1
1.1.3 EMC dB Units 3
1.2 Fourier Series Representation of Periodic Signals 6
1.3 Spectrum of a Clock Signal 7
1.4 Effect of the Rise Time, Signal Amplitude, Fundamental Frequency, and Duty Cycle on the Signal Spectrum 15
1.4.1 Effect of the Rise Time 15
1.4.2 Effect of the Signal Amplitude 15
1.4.3 Effect of the Fundamental Frequency 18
1.4.4 Effect of the Duty Cycle 20
1.5 Laboratory Exercises 22
1.5.1 Spectrum of a Digital Clock Signal 22
1.5.2 Laboratory Equipment and Supplies 22
1.5.3 Measured Spectrum vs. Calculated Spectrum 23
1.5.4 Effect of the Rise Time 27
1.5.5 Effect of the Signal Amplitude 31
1.5.6 Effect of the Fundamental Frequency 33
1.5.7 Effect of the Duty Cycle 37
References 43
2 EM Coupling Mechanisms 45
2.1 Wavelength and Electrical Dimensions 45
2.1.1 Concept of a Wave 45
2.1.2 Uniform Plane EM Wave in Time Domain 46
2.1.3 Uniform Plane EM Wave in Frequency Domain 47
2.2 EMC Interference Problem 50
2.3 Capacitive Coupling 53
2.3.1 Shielding to Reduce Capacitive Coupling 56
2.4 Inductive Coupling 59
2.4.1 Shielding to Reduce Inductive Coupling 61
2.5 Crosstalk Between PCB Traces 66
2.6 Common-Impedance Coupling 70
2.7 Laboratory Exercises 72
2.7.1 Crosstalk Between PCB Traces 72
References 76
3 Non-Ideal Behavior of Passive Components 77
3.1 Resonance in RLC Circuits 77
3.1.1 "Pure" Series Resonance - Non-Ideal Capacitor Model 77
3.1.2 "Pure" Parallel Resonance - Ferrite Bead Model 81
3.1.3 "Hybrid" Series Resonance - Non-Ideal Resistor Model 83
3.1.4 "Hybrid" Parallel Resonance - Non-Ideal Inductor Model 85
3.2 Non-Ideal Behavior of Resistors 87
3.2.1 Circuit Model and Impedance 87
3.2.2 Parasitic Capacitance Estimation - Discrete Components 89
3.2.3 Parasitic Capacitance Estimation - PCB Components 94
3.3 Non-Ideal Behavior of Capacitors 97
3.3.1 Circuit Model and Impedance 97
3.3.2 Parasitic Inductance Estimation - Discrete Components 99
3.3.3 Parasitic Inductance Estimation - PCB Components 101
3.4 Non-Ideal Behavior of Inductors 104
3.4.1 Circuit Model and Impedance 104
3.4.2 Parasitic Capacitance Estimation - Discrete Components 106
3.4.3 Parasitic Capacitance Estimation - PCB Components 108
3.5 Non-Ideal Behavior of a PCB Trace 111
3.5.1 Circuit Model and Impedance 111
3.6 Impact of the PCB Trace Length on Impedance of the Passive Components 114
3.6.1 Impedance of a Resistor - Impact of the PCB Trace 114
3.6.2 Impedance of a Capacitor - Impact of the PCB Trace 114
3.6.3 Impedance of an Inductor - Impact of the PCB Trace 114
3.6.4 Impedance of an Inductor vs. Impedance of the PCB Trace 118
3.7 Laboratory Exercises 118
3.7.1 Non-Ideal Behavior of Capacitors and Inductors, and Impact of the PCB Trace Length on Impedance 118
3.7.2 Laboratory Equipment and Supplies 119
3.7.3 Laboratory Procedure - Non-Ideal Behavior of Capacitors and Inductors 121
3.7.4 Laboratory Procedure - Impact of the PCB Trace Length on Impedance 122
References 122
4 Power Distribution Network 125
4.1 CMOS Inverter Switching 125
4.2 Decoupling Capacitors 125
4.2.1 Decoupling Capacitor Impact - Measurements 130
4.2.2 Decoupling Capacitor Configurations 137
4.3 Decoupling Capacitors and Embedded Capacitance 147
4.3.1 Decoupling Capacitors and Closely vs. Not Closely Spaced Power and Ground Planes 147
4.3.2 Impact of the Number and Values of the Decoupling Capacitors 156
4.4 Laboratory Exercises 168
4.4.1 Decoupling Capacitors 168
4.4.2 Embedded Capacitance and Decoupling Capacitors 172
References 176
5 EMC Filters 177
5.1 Insertion Loss Definition 177
5.2 Basic Filter Configurations 177
5.3 Source and Load Impedance Impact 177
5.4 What Do We Mean by Low or High Impedance? 179
5.5 LC and CL Filters 181
5.5.1 LC Filter 181
5.5.2 CL Filter 186
5.5.3 LC Filter vs. CL Filter 189
5.6 Pi and T Filters 195
5.6.1 Pi Filter 195
5.6.2 T Filter 196
5.6.3 Pi Filter vs. T Filter 197
5.7 LCLC and CLCL Filters 202
5.7.1 LCLC Filter 202
5.7.2 CLCL Filter 205
5.7.3 LCLC Filter vs. CLCL Filter 206
5.8 Laboratory Exercises 212
5.8.1 Input Impedance and Insertion Loss of EMC Filters 212
5.8.2 Laboratory Equipment and Supplies 212
5.8.3 Laboratory Procedure 214
References 217
6 Transmission Lines - Time Domain 219
6.1 Introduction 219
6.1.1 Transmission Line Effects 219
6.1.2 When a Line Is not a Transmission Line 219
6.1.3 Transmission Line Equations 226
6.2 Transient Analysis 229
6.2.1 Reflections at a Resistive Load 229
6.2.2 Reflections at a Resistive Discontinuity 236
6.2.3 Reflections at a Shunt Resistive Discontinuity 239
6.2.4 Reflections with Transmission Lines in Parallel 241
6.2.5 Reflections at a Reactive Load 245
6.2.6 Reflections at a Shunt Reactive Discontinuity 258
6.3 Eye Diagram 266
6.3.1 Fundamental Concepts 266
6.3.2 Impact of Driver, HDMI Cable, and Receiver 271
6.4 Laboratory Exercises 275
6.4.1 Transmission Line Reflections 275
6.4.2 Laboratory Equipment and Supplies 275
6.4.3 Reflections at a Resistive Load 278
6.4.4 Bounce Diagram 281
6.4.5 Reflections at a Resistive Discontinuity 282
References 285
7 Transmission Lines - Frequency Domain 287
7.1 Frequency-Domain Solution 287
7.1.1 The Complete Circuit Model - Voltage, Current, and Input Impedance along the Transmission Line 290
7.1.2 Frequency-Domain Solution - Example 307
7.2 Smith Chart and Input Impedance to the Transmission Line 316
7.2.1 Smith Chart Fundamentals 316
7.2.2 Input Impedance to the Transmission Line 326
7.3 Standing Waves and VSWR 332
7.4 Laboratory Exercises 336
7.4.1 Input Impedance to Transmission Line - Smith Chart 336
7.4.2 Laboratory Procedure - Smith Chart 336
References 337
8 Antennas and Radiation 339
8.1 Bridge Between the Transmission Line Theory and Antennas 339
8.2 Electric (Hertzian) Dipole Antenna 340
8.2.1 Wave Impedance and Far-Field Criterion 343
8.2.2 Wave Impedance in the Near Field 344
8.3 Magnetic Dipole Antenna 345
8.3.1 Wave Impedance and Far-Field Criterion 346
8.3.2 Wave Impedance in the Near Field 347
8.4 Half-Wave Dipole and Quarter-Wave Monopole Antennas 348
8.4.1 Half-Wave Dipole Antenna 348
8.4.2 Quarter-Wave Monopole Antenna 351
8.5 Balanced-Unbalanced Antenna Structures and Baluns 351
8.5.1 Balanced and Unbalanced Half-Wave Dipole Antenna 352
8.5.2 Sleeve (Bazooka) Balun 355
8.5.3 Input Impedance to the Transmission Line 357
8.5.4 Quarter-Wavelength Sleeve Balun 358
8.6 Sleeve Dipole Antenna Design and Build 360
8.6.1 Symmetrically Driven Half-Wave Dipole Antenna 360
8.6.2 Asymmetrically Driven Dipole Antenna and a Sleeve Dipole 361
8.6.3 Sleeve Dipole Antenna Design 362
8.6.4 Sleeve Dipole Antenna Design Through Simulation 362
8.6.5 Construction and Tuning of a Sleeve Dipole 364
8.7 Antennas Arrays 368
8.8 Log-Periodic Antenna 368
8.9 Biconical Antenna 372
8.10 Antenna Impedance and VSWR 373
8.11 Laboratory Exercises 375
8.11.1 Log-Periodic and Bicon Antenna Impedance and VSWR Measurements 376
8.11.2 Loop Antenna Construction 377
References 381
9 Differential- and Common-Mode Currents and Radiation 383
9.1 Differential- and Common-Mode Currents 383
9.1.1 Common-Mode Current Creation 385
9.2 Common-Mode Choke 387
9.3 Differential-Mode and Common-Mode Radiation 391
9.3.1 Differential-Mode Radiation 395
9.3.2 Common-Mode Radiation 397
9.4 Laboratory Exercises 399
9.4.1 Differential-Mode and Common-Mode Current Measurement 399
9.4.2 Laboratory Equipment and Supplies 399
9.4.3 Laboratory Procedure - Differential-Mode and Common-Mode Current Measurements 399
References 406
10 Return-Current Path, Flow, and Distribution 407
10.1 Return-Current Path 407
10.2 Return-Current Flow 412
10.3 Return-Current Distribution 415
10.3.1 Microstrip Line PCB 415
10.3.2 Stripline PCB 422
10.4 Laboratory Exercises 430
10.4.1 Path of the Return Current 430
References 438
11 Shielding to Prevent Radiation 439
11.1 Uniform Plane Wave 439
11.1.1 Skin Depth 442
11.1.2 Current Density in Conductors 443
11.1.3 Reflection and Transmission at a Normal Boundary 444
11.2 Far-Field Shielding 447
11.2.1 Shielding Effectiveness - Exact Solution 450
11.2.2 Shielding Effectiveness - Approximate Solution - Version 1 454
11.2.3 Shielding Effectiveness - Approximate Solution - Version 2 456
11.2.4 Shielding Effectiveness - Simulations 458
11.3 Near-Field Shielding 463
11.3.1 Electric Field Sources 463
11.3.2 Magnetic Field Sources 465
11.3.3 Shielding Effectiveness - Simulations 466
11.3.4 Shielding Effectiveness - Measurements 470
11.4 Laboratory Exercises 477
11.4.1 Shielding Effectiveness - Simulations 477
11.4.2 Shielding Effectiveness - Measurements 477
References 481
12 SMPS Design for EMC 483
12.1 Basics of SMPS Operation 483
12.1.1 Basic SMPS Topology 483
12.1.2 Basic SMPS Design 486
12.2 DC/DC Converter Design with EMC Considerations 491
12.2.1 Switching Frequency 491
12.2.2 Output Inductor 493
12.2.3 Output Capacitor 494
12.2.4 Catch Diode 495
12.2.5 Input Capacitor 495
12.2.6 Bootstrap Capacitor 496
12.2.7 Undervoltage Lockout 496
12.2.8 Feedback Pin 496
12.2.9 Compensation Network 497
12.2.10 Complete Regulator Circuitry 498
12.2.11 EMC Considerations 498
12.3 Laboratory Exercises 500
12.3.1 SMPS Design and Build 500
12.3.2 Laboratory Equipment and Supplies 500
12.3.3 Laboratory Procedure 501
References 502
A Evaluation of EMC Emissions and Ground Techniques on 1- and 2-Layer PCBs with Power Converters 503
A. 1 Top-Level Description of the Design Problem 503
A.. 1 Functional Block Details 503
A.1. 2 One-Layer Board Topologies 506
A.1. 3 Two-Layer Board Topologies 507
A. 2 DC/DC Converter - Baseline EMC Emissions Evaluation 509
A.2. 1 CISPR 25 Radiated Emissions Test Results 510
A.. 2 CISPR 25 Conducted Emissions (Voltage Method) Test Results 512
A.2. 3 CISPR 25 Conducted Emissions (Current Method) Test Results 515
A. 3 DC/DC Converter - EMC Countermeasures - Radiated Emissions Results 515
A.3. 1 EMC-A and EMC-E Input and Output Capacitor Impact 515
A.3. 2 EMC-A Input Inductor Impact 518
A.. 3 EMC-C Switching Inductor Impact 519
A.3. 4 EMC-B and EMC-D Snubber Impact 521
A.3. 5 EMC-A, EMC-E - Conducted Emissions Countermeasures Impact 523
A.3. 6 Impact of the Shield Frame 524
A. 4 DC/DC Converter - EMC Countermeasures - Conducted Emissions Results - Voltage Method 528
A.4. 1 EMC-A and EMC-E Input and Output Capacitor Impact 528
A.4. 2 EMC-A Input Inductor Impact 529
A.4. 3 EMC-A Additional Input Capacitors Impact 530
A.. 4 EMC-A Input Inductor Impact 531
A.4. 5 EMC-C Switching Inductor Impact 532
A.4. 6 EMC-B and EMC-D Snubber Impact 533
A. 5 DC/DC Converter - EMC Countermeasures - Conducted Emissions Results - Current Method 535
A.5. 1 EMC-A, EMC-C, and EMC-E Input and Output Capacitor and Inductor Impact 535
A.5. 2 EMC-B and EMC-D Snubber Impact 536
A. 6 PCB Layout Considerations 537
A.6. 1 Introduction 537
A.6. 2 Visualizing Complete Forward and Return Paths 538
A.6. 3 Return-Plane Split in AC-DC Converter 543
A. 7 AC/DC Converter Design with EMC Considerations 544
A.7. 1 AC/DC Converter Schematics and Design Requirements 544
A.7. 2 EMC Considerations 546
A. 8 AC/DC Converter - Baseline EMC Emissions Evaluation 548
A.8. 1 Radiated Emissions Test Results 548
A.8. 2 Conducted Emissions Test Results 551
A. 9 AC/DC Converter - EMC Countermeasures - Conducted and Radiated Emissions Results 552
A.9. 1 Conducted Emissions Test Results 553
A.9. 2 Radiated Emissions Test Results 555
A. 10 Complete System - Conducted and Radiated Emissions Results 557
A.0. 1 Complete System and Board Topologies 557
A.10. 2 Conducted Emissions Results 558
A.10. 3 Radiated Emissions Results 562
A.10. 4 Conclusions 564
References 565
Index 567
