EMC for Product Designers (eBook)

EMC for Product Designers 2
Copyright page 3
Contents 4
Preface 12
Part 1: Legislation and standards 16
Chapter 1: Introduction 16
What is EMC? 16
Portable electronic devices in aircraft 17
Interference to medical devices 18
Thermostats 21
The quacking duck 21
Compatibility between and within systems 22
Intra-system EMC 22
Inter-system EMC 22
When intra-system meets inter-system 23
The scope of EMC 23
Malfunction of control systems 23
Immunity of data and programme processing 24
Interference with radio reception 25
Disturbances of the mains supply 28
Power line telecoms 29
Other EMC issues 33
The compatibility gap 34
Electromagnetic fields and human health 35
ICNIRP basic restrictions 35
Athermal effects 37
Chapter 2: The EMC Directive 38
History 38
The New Approach Directives 38
Background to the legislation 39
The first EMC Directive 39
The second EMC Directive 41
What changes? 42
Scope, requirements and exceptions 42
The CE mark and the paperwork 46
Manufacturing quality assessment 50
Fixed installations 51
Systems 56
Implementation, enforcement and sanctions 56
Compliance of apparatus with the Directive 58
Self certification and internal production control 59
The notified body 61
Testing 63
Using standards 63
Action for compliance for a product manufacturer 67
Chapter 3: The R& TTE Directive
The implementation of the R& TTE Directive
Scope 70
Requirements 71
The process of conformity assessment 72
Procedures 73
Classes of radio transmitter 75
Notification 77
Information requirements 78
Marking of equipment and documentation 79
Chapter 4: Commercial standards 80
The standards making bodies 80
The International Electrotechnical Commission 80
CENELEC and ETSI 85
Generic standards – emissions 89
EN 61000-6-3: 2001 + A11: 2004 89
EN 61000-6-4: 2001 90
Main product standards: emissions 90
EN 55011: 1998 + A1: 1999 + A2: 2002 90
EN 55014-1: 2000 + A1: 2001 + A2: 2002 91
EN 55022: 1998 + A1: 2000 + A2: 2003 92
Generic standards – immunity 93
EN 61000-6-1: 2001 93
EN 61000-6-2: 2005 94
Basic standards – EN 61000-3-X and -4-X 94
EN 61000-3-X 95
EN 61000-4-X 96
Product standards 100
Broadcast receivers and associated equipment 101
Household appliances, electric tools and similar apparatus 102
Lighting equipment 103
Information technology equipment 104
Professional AV and entertainment lighting equipment 104
Equipment for measurement, control and laboratory use 105
Fire, intruder and social alarm systems 106
Telecommunication network equipment 106
Radio equipment 107
Marine navigation equipment 108
Medical electrical equipment 108
Future multi-media 109
Other product standards 110
Other standards not related to the EMC Directive 111
FCC Rules 111
Measurement standards 113
RF emissions limits 113
Chapter 5: Other standards and legislation 115
Automotive 115
The Automotive EMC Directive 115
ISO, CISPR and SAE standards 117
Vehicle manufacturers 119
Specialist requirements 120
Military 121
DEF STAN 59-41 122
MIL STD 461 124
Aerospace 126
DO-160/ED-14 126
Rail 128
Railway Group Standards 128
London Underground standards 130
EN 50121 130
Part 2: Testing 133
Chapter 6: RF emissions measurements 133
Emissions measuring instruments 133
Measuring receiver 133
Spectrum analyser 134
Receiver specifications 136
Transducers 141
Antennas for radiated field 142
LISNs and probes for cable measurements 146
Near field probes 154
The GTEM for emissions tests 155
Sites and facilities 156
Radiated emissions 156
Test methods 163
Test set-up 163
Test procedure 165
Tests above 1GHz 167
Military emissions tests 168
Measurement uncertainty 170
Applying measurement uncertainty 170
Sources of uncertainty 171
Chapter 7: Immunity tests 179
RF immunity 179
Equipment 179
Facilities 187
Test methods 190
Conducted RF immunity 194
Measurement uncertainty for RF immunity 198
ESD and transient immunity 199
ESD 199
Electrical fast transient (EFT) bursts 202
Surge 204
Other transient immunity tests 206
Sources of variability 208
Measurement uncertainty for transient tests 209
Military susceptibility tests 209
Continuous LF and RF susceptibility 209
Transient susceptibility 210
Chapter 8: Low frequency tests 211
Mains harmonic and flicker emission 211
Equipment 212
Test conditions 214
Equipment classification and limits 214
Flicker 216
Magnetic field and power quality immunity 220
Magnetic field 220
Voltage dips and interrupts 221
Chapter 9: Test planning 224
The need for a test plan 224
The requirements of accreditation 224
The requirements of standards 224
The requirements of the customer 226
Contents of the test plan 226
Description of the equipment under test (EUT) 226
Statement of test objectives 227
The tests to be performed 228
EUT exercising software and ancillary equipment or simulators 229
Requirements of the test facility 231
Details of the test set-up 232
How to evaluate test results 233
Immunity performance criteria 234
The generic criteria 235
Interpreting the generic criteria 235
Part 3: Design 237
Chapter 10: Interference coupling mechanisms 237
Source and victim 237
Common impedance coupling 238
Distributed near field coupling 241
Mains coupling 243
Radiated coupling 244
Coupling modes 247
Emissions 249
Radiated emissions 250
Conducted emissions 253
Immunity 256
Radiated field 256
Transients 260
Electrostatic discharge 264
LF magnetic fields 266
Supply voltage phenomena 268
Mains harmonics 269
The supplier’s problem 269
Non-linear loads 270
Chapter 11: Layout and grounding 273
Equipment layout and grounding 274
System partitioning 274
Grounding 276
Ground systems 279
PCB layout 283
Ground layout without a ground plane 283
Using a ground plane 286
Configuring I/O and circuit grounds 297
Rules for PCB layout 301
Chapter 12: Digital and analogue circuit design 303
Design for emissions control 303
The Fourier spectrum 303
Radiation from logic circuits 307
Digital circuit decoupling 315
Analogue circuits: emissions 321
The switching power supply 322
Other power switching circuits 329
Design for immunity 329
Digital circuits: interference paths 330
Logic noise immunity 336
Signal integrity and ground bounce 339
The microprocessor watchdog 341
Defensive programming 344
Transient and RF immunity – analogue circuits 348
Chapter 13: Interfaces and filtering 355
Cables and connectors 355
The mode of propagation 355
Cable return currents 356
Crosstalk 357
Cable screens at low frequencies 359
Cable screens at RF 361
Types of cable screen 362
Screened cable connections 364
Unscreened cables 367
Structured cabling: UTP versus STP 371
Filtering and suppression 372
Filter configuration 372
Components 376
Mains filters 382
I/O filtering 388
Transient suppression 390
Contact suppression 393
Chapter 14: Shielding 396
Shielding theory 396
Shielding theory for an infinite barrier 397
LF magnetic fields 399
The effect of apertures 400
The shield as ground reference 404
The image plane 405
Shielding practice 407
Shielding hardware 407
Conductive coatings 410
Windows and ventilation slots 412
Shields on the PCB 415
Standardization of enclosure SE 416
Chapter 15: Systems EMC 418
System versus product EMC 418
Compliance requirements 418
Functional requirements 419
Earthing and bonding 419
The purpose of the earth 419
Installation techniques for multi-purpose earthing 421
Earth conductors 423
Bonding techniques 423
Cabinets, cubicles and chambers 425
Transfer impedance of the earth reference 426
Layout and placement within the enclosure 427
Conductive hardware 430
Installation and maintenance of screened enclosures 431
Cabling 432
Cable classification, segregation and routing 432
Parallel Earth Conductor (PEC) techniques 435
Lightning protection 436
How lightning phenomena can affect electronic apparatus 436
Overview of design of a lightning protection system (LPS) 438
Chapter 16: EMC management 441
Managing the EMC process 441
Putting EMC in context 441
The EMC co-ordinator 442
The design process 443
The product specification 443
Design rules 443
Design reviews 444
Identifying EMC-critical aspects 444
Test management 445
When to do the tests 445
In-house or external? 447
The various types of report 448
Compliance during production and beyond 449
Degrees of quality assurance 450
Production QA testing 450
Engineering change control 452
The control plan and documentation for Directives 452
The purpose of the control plan 452
The EMC Assessment 453
Contents 454
Appendix A: Design checklist 456
Appendix B: CAD for EMC 459
Overview 459
Modelling packages 460
Circuit CAD 461
Appendix C: Case studies 463
Cockpit display 463
Liquid tank sensor 464
The problem with wall-warts 465
The dipole problem: a box in two halves 469
Appendix D: Useful tables and formulae 472
The deciBel 472
Antennas 473
Fields 474
Shielding 477
Capacitance, inductance and PCB layout 478
Filters 481
Fourier series 482
Appendix E: The EU and EEA countries 485
Glossary 486
A 486
B 486
C 486
D 486
E 486
F 487
G 487
H 487
I 487
L 487
M 487
N 487
O 487
P 487
Q 488
R 488
S 488
T 488
U 488
V 488
Z 488
Bibliography 489
Index 504
A 504
B 504
C 504
D 505
E 506
F 507
G 507
H 508
I 508
J 508
K 508
L 508
M 509
N 509
O 509
P 510
Q 510
R 510
S 511
T 512
U 513
V 513
W 513
Z 513