Audio Power Amplifier Design Handbook (eBook)

Douglas Self (Autor)

eBook Download: PDF

2002 | 3. Auflage
427 Seiten
Elsevier Science (Verlag)
978-0-08-049961-1 (ISBN)

Infos

Douglas Self has called upon his years of experience at the cutting edge of audio design to compile this handbook for professionals and students. The book provides a clear and practical guide to the state of the art, and includes detailed design and construction information.

This new edition is more comprehensive than ever, with a new chapter on Class G amplifiers and further new material on output coils, thermal distortion, relay distortion, ground loops, triple EF output stages and convection cooling.

Douglas Self has dedicated himself to demystifying amplifier design and establishing empirical design techniques based on electronic design principles and experimental data. His rigorous and thoroughly practical approach has established him as a leading authority on amplifier design, especially through the pages of Electronics World where he is a regular contributor.

* Discover the secrets of cutting-edge audio design
* The definitive professional handbook for amplifier designers
* Includes a new chapter on Class G amplifiers

Inhalt

Contents 5
Synopsis 7
Preface 15
1 Introduction and general survey 17
The economic importance of power amplifiers 17
The study of amplifier design 19
Misinformation in audio 21
The performance requirements for amplifiers 38
Acronyms 43
2 History, architecture and negative feedback 46
A brief history of amplifiers 46
Amplifier architectures 47
Power amplifier classes 49
AC and DC coupled amplifiers 57
Negative feedback in power amplifiers 60
3 The general principles of power amplifiers 76
How a generic amplifier works 76
The advantages of convention 78
The eight distortions 79
The performance of a standard amplifier 83
Open-loop linearity and how to determine it 83
Direct o/l gain measurement 84
Using model amplifiers 86
The concept of the Blameless amplifier 87
4 The small signal stages 89
The role of the input stage 89
Distortion from the input stage 90
BJTs vs FETs for the input stage 91
Singleton input stage versus differential pair 92
The input stage distortion in isolation 92
Input stage balance 95
The joy of current-mirrors 96
Improving input-stage linearity 98
Radical methods of improving input linearity 99
Input stage cascode configurations 101
Input noise and how to reduce it 101
Offset and match: the DC precision issue 105
The input stage and the slew-rate 106
The voltage-amplifier stage 107
Measuring VAS distortion in isolation 108
VAS operation 109
VAS distortion 111
Linearising the VAS: active load techniques 111
VAS enhancements 113
The importance of voltage drive 115
The balanced VAS 116
The VAS and manipulating open-loop bandwidth 117
Manipulating open-loop bandwidth 120
5 The output stage I 122
Classes and devices 122
The distortions of the output 125
The emitter-follower output 128
The CFP output 130
Quasi-complementary outputs 135
Triple-based output configurations 137
Triple EF output stages 137
Distortion and its mechanisms 138
Large-signal distortion (Distortion 3a) 139
Crossover distortion (Distortion 3b) 155
Switching distortion (Distortion 3c) 169
Thermal distortion 169
Thermal distortion in a power amp IC 172
Selecting an output stage 173
Closing the loop: distortion in complete amplifiers 174
6 The output stage II 179
Distortion number 4: VAS loading distortion 179
Distortion number 5: rail decoupling distortion 181
Distortion number 6: induction distortion 184
Distortion number 7: NFB takeoff point distortion 186
Distortion number 8: capacitor distortion 188
Design example: a 50 W Class-B amplifier 191
7 Compensation, slew-rate, and stability 199
Frequency compensation in general 199
Dominant-pole compensation 200
Lag compensation 201
Including the output stage: inclusive Miller compensation 202
Nested feedback loops 203
Two-pole compensation 204
Output networks 206
Crosstalk in amplifier output inductors 219
Reactive loads and speaker simulation 225
Loudspeaker loads and output stages 230
Enhanced loudspeaker currents 236
Amplifier instability 238
Speed and slew-rate in audio amplifiers 240
8 Power supplies and PSRR 251
Power supply technologies 251
Design considerations for power supplies 254
9 Class-A power amplifiers 271
An introduction to class-A 271
Class-A configurations and efficiency 272
Output stages in Class-A 275
Quiescent current control systems 279
A novel quiescent current controller 281
A Class-A design 283
The trimodal amplifier 285
Load impedance and operating mode 287
Efficiency 288
On Trimodal biasing 293
Class-A/AB mode 294
Class-B mode 297
The mode-switching system 297
Thermal design 298
A complete Trimodal amplifier circuit 299
The power supply 302
The performance 302
10 Class-G power amplifiers 306
The principles of Class-G 306
Introducing series class-G 307
Efficiency of Class-G 309
Practicalities 312
The biasing requirements 312
The linearity issues of series Class-G 314
The static linearity 315
Practical Class-G design 318
Controlling small-signal distortion 318
The performance 322
Deriving a new kind of amplifier: Class-A + C 325
Adding two-pole compensation 327
Further variations on Class-G 329
11 FET output stages 330
The characteristics of power FETS 330
FET vs BJT output stages 331
IGBTs 332
Power FET output stages 334
Power FETs and bipolars: the linearity comparison 337
FETs in Class-A stages 337
12 Thermal compensation and thermal dynamics 341
Why quiescent conditions are critical 341
Accuracy required of thermal compensation 342
Basic thermal compensation 347
Assessing the bias errors 348
Thermal simulation 348
Modelling the EF output stage 350
Modelling the CFP output stage 358
The integrated absolute error criterion 360
Improved thermal compensation: the emitter-follower stage 361
Improved compensation for the CFP output stage 364
A better sensor position 365
A junction-temperature estimator 366
A junction estimator with dynamics 368
Variable-tempco bias generators 373
Thermal dynamics in reality 380
13 Amplifier and loudspeaker protection 386
Categories of amplifier protection 386
Overload protection 388
Catching diodes 399
DC-offset protection 400
Thermal protection 408
Powering auxiliary circuitry 410
14 Grounding and practical matters 412
Audio amplifier PCB design 412
Amplifier grounding 420
Ground loops: how they work and how to deal with them 421
Class I and Class II 428
Mechanical layout and design considerations 430
15 Testing and safety 434
Testing and fault-finding 434
Safety 436
Index 439

Produkt-Details

• Erscheint lt. Verlag: 16.5.2002
• Sprache: englisch
• Themenwelt: Kunst / Musik / Theater ► Musik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• ISBN-10: 0-08-049961-9 / 0080499619
• ISBN-13: 978-0-08-049961-1 / 9780080499611