A complete crossover displacement power amplifier circuit
The measured performance
The effect of loading changes
The efficiency of crossover displacement
Other methods of push–pull displacement control
Summary
Advantages
Disadvantages
Chapter 12 Class-G power amplifiers
The principles of Class-G
Introducing series Class-G
Efficiency of Class-G
Practicalities
The biasing requirements
The linearity issues of series Class-G
The static linearity
Practical Class-G design
Controlling small-signal distortion
The performance
Deriving a new kind of amplifier: Class-A + C
Adding two-pole compensation
Further variations on Class-G
Chapter 13 Class-D amplifiers
History
Basic principles
Technology
Protection
Output filters
Efficiency
Chapter 14 FET output stages
The characteristics of power FETs
FET versus BJT output stages
Advantages of FETs
Disadvantages of FETs
IGBTs
Power FET output stages
Power FETs and bipolars: the linearity competition
FETs in Class-A stages
Chapter 15 Thermal compensation and thermal dynamics
Why quiescent conditions are critical
Accuracy required of thermal compensation
Basic thermal compensation
Assessing the bias errors
Thermal simulation
Modeling the EF output stage
Modeling the CFP output stage
The Integrated Absolute Error Criterion
Improved thermal compensation for the EF stage
Improved compensation for the CFP output stage
A better sensor position
A junction-temperature estimator
A junction estimator with dynamics
Conclusions about the simulations
Power transistors with integral temperature sensors
Variable-tempco bias generators
Creating a higher tempco
Ambient temperature changes
Creating a lower tempco
Current compensation
Early effect in output stages
Thermal dynamics by experiment
Crossover distortion against time – some results
More measurements – conventional and ThermalTrak
Chapter 16 The design of DC servos
DC offset trimming
DC offset control by servo-loop
The advantages of DC servos
Basic servo configurations
Noise, component values, and the roll-off
Non-inverting integrators
The 2C integrator
The 1C integrator
Choice of integrator type
Choice of op-amps
Servo authority
Design of LF roll-off point
Servo overload
Servo testing
Performance issues
Multi-pole servos
Chapter 17 Amplifier and loudspeaker protection
Categories of amplifier protection
Semiconductor failure modes
Overload protection
Overload protection by fuses
Electronic overload protection
Plotting the protection locus
Simple current limiting
Single-slope VI limiting
Dual-slope VI limiting
VI limiting and temperature effects
Simulating overload protection systems
Testing the overload protection
Speaker short-circuit detection
Catching diodes
DC offset protection
DC protection by fuses
Relay protection and muting control
Filtering for DC protection
The single RC filter
The dual RC filter
The second-order active filter
Bidirectional DC detection
The conventional two-transistor circuit
The one-transistor version
The differential detector
The Self detector
Distortion in output relays
Output crowbar DC protection
Protection by power-supply shutdown
Thermal protection
Mains-fail detection
Powering auxiliary circuitry
Chapter 18 Grounding, cooling, and layout
Audio amplifier PCB design
Crosstalk
Rail induction distortion
Mounting output devices on the main PCB
Advantages
Disadvantages
Single- and double-sided PCBs
Power-supply PCB layout
Power amplifier PCB layout details
The audio PCB layout sequence
Miscellaneous points
Amplifier grounding
Ground loops: how they work and how to deal with them
Hum injection by mains grounding currents
Hum injection by transformer stray magnetic fields
Hum injection by transformer stray capacitance
Ground currents inside equipment
Balanced mains power
Class-I and Class-II
Warning
Cooling
Convection cooling
Heat-sink materials
Heat-sink compounds
Thermal washers
Fan cooling
Fan control systems
Fan failure safety measures
Heat pipes
Mechanical layout and design considerations
Wiring layout
Semiconductor installation
Chapter 19 Testing and safety
Testing and fault-finding
Powering up for the first time
Safety when working on equipment
Warning
Safety regulations
Electrical safety
Shocks from the mains plug
Touch current
Case openings
Equipment temperature and safety
Touching hot parts
Instruction manuals
Chapter 20 Power amplifier input systems
External signal levels
Internal signal levels
The choice of op-amps
Unbalanced inputs
Balanced interconnections
Advantages
Disadvantages
Common-mode rejection ratio
Balanced connectors
Balanced signal levels
Balanced inputs: electronic versus transformer
The basic balanced input
Common-mode rejection in the basic balanced input
The practical balanced input
Combined unbalanced and balanced inputs
Superbal input
Switched-gain balanced inputs
Variable-gain balanced inputs
High-impedance balanced inputs
The inverting two-op-amp input
The instrumentation amplifier
Transformer balanced inputs
Input overvoltage protection
Noise and the input system
Low-noise balanced inputs
…And quieter yet
Noise reduction in real life
Unbalanced and balanced outputs
Unbalanced outputs
Ground-canceling outputs
Balanced outputs
Quasi-floating outputs
Transformer balanced outputs
Using a balanced power amplifier interface
Chapter 21 Input processing and auxiliary subsystems
Ground-lift switches
Phase reversal facility
Gain control
Subsonic filtering: high-pass
Ultrasonic filtering: low-pass
Combined filters
Electronic crossovers
Digital signal processing
Signal-present indication
Output level indication
Signal activation
Twelve-Volt trigger activation
Infrared remote control
Other amplifier facilities
Index
A
B
C
D
E
F
G
H
I
J
L
M
N
O
P
Q
R
S
T
U
V
W
X
Z
Nội dung
[...]... Importance of Power Amplifiers Audiopower amplifiers are of considerable economic importance They are built in their hundreds of thousands every year, and have a history extending back to the 1920s It is therefore surprising there have been so few books dealing in any depth with solid-state power amplifier design The first aim of this text is to fill that need, by providing a detailed guide to the many design. .. must be taken when a power amplifier is designed The second aim is to disseminate the results of the original work done on amplifier design in the last few years The unexpected result of these investigations was to show that power amplifiers of extraordinarily low distortion could be designed as a matter of routine, without any unwelcome side-effects, so long as a relatively simple design methodology was... discrete power amplifier design is rather unenterprising, given the enormous outpouring of ingenuity in the design of analog integrated circuits Advances in op-amp design would appear to be particularly relevant I have therefore spent some considerable time studying this massive body of material and I have had to regretfully conclude that it is actually a very sparse source of inspiration for new audio power. .. Survey 5 Power amplifier design has often been treated as something of a black art, with the implication that the design process is extremely complex and its outcome not very predictable I hope to show that this need no longer be the case, and that power amplifiers are now designable – in other words it is possible to predict reasonably accurately the practical performance of a purely theoretical design. .. 266 Power- supply technologies 266 Simple unregulated power supplies 266 Advantages 266 Disadvantages 266 Linear regulated power supplies 267 Advantages 267 Disadvantages 267 Switch-mode power supplies 268 Advantages 268 Disadvantages 269 A devious alternative to regulated power. .. output relays 466 Output crowbar DC protection 469 Protection by power- supply shutdown 470 Thermal protection 471 Mains-fail detection 475 Powering auxiliary circuitry 477 Chapter 18 Grounding, cooling, and layout 479 Audio amplifier PCB design 479 Crosstalk 479 Rail induction distortion ... specified load capacitance across the high-impedance output This does not appear to be a promising approach to making audiopower amplifiers ● Much of the op-amp material is concerned with the common-mode performance of the input stage This is pretty much irrelevant to power amplifier design ● Many circuit techniques rely heavily on the matching of device characteristics possible in IC fabrication, and... therefore not pursued the FET route very far Similarly, most of my practical design experience has been on amplifiers of less than 300 W power output, and so heavyduty designs for large-scale public address (PA) work are also under-represented I think this is preferable to setting down untested speculation The Study of Amplifier Design Although solid-state amplifiers have been around for some 40 years, it... amplifiers of extremely low distortion (sub-0.001% at 1 kHz) to be designed and built as a matter of routine, using only modest amounts of global negative feedback Misinformation in Audio Few fields of technical endeavor are more plagued with errors, misstatements and confusion than audio In the last 20 years, the rise of controversial and non-rational audio hypotheses, gathered under the title Subjectivism has... operation of almost any design Such problems arise because audio electronics is a more technically complex subject than it at first appears It is easy to cobble together some sort of power amplifier that works, and this can give people an altogether exaggerated view of how deeply they understand what they have created In contrast, no one is likely to take a ‘subjective’ approach to the design of an aeroplane . x0 y0 w0 h1" alt="" Audio Power Amplifi er Design Handbook This book is dedicated to Julie, without whom it would not have happened. Audio Power Amplifi er Design Handbook Fifth Edition Douglas. Cataloguing-in-Publication Data Self, Douglas. Audio power amplifi er design handbook. – 5th ed. 1. Audio amplifi ers Design. 2. Power amplifi ers Design. I. Title 621.3’81535—dc22 Library. gurations 264 Chapter 9 Power supplies and PSRR 266 Power- supply technologies 266 Simple unregulated power supplies 266 Advantages 266 Disadvantages 266 Linear regulated power supplies 267