Power Sources and Supplies: World Class Designs (eBook)

Front Cover 1
Power Sources and Supplies: World Class Designs 4
Copyright Page 5
Contents 6
Preface 10
About the Editor 12
About the Contributors 14
Chapter 1: An Introduction to the Linear Regulator 16
1.1 Basic Linear Regulator Operation 17
1.2 General Linear Regulator Considerations 18
1.3 Linear Power Supply Design Examples 21
Chapter 2: Basic Switching Circuits 28
2.1 Energy Storage Basics 29
2.2 Buck Converter 30
2.3 Boost Converter 32
2.4 Inverting Boost Converter 34
2.5 Buck-Boost Converter 34
2.6 Transformer Isolated Converters 35
2.7 Synchronous Rectification 38
2.8 Charge Pumps 40
Chapter 3: DC-DC Converter Design and Magnetics 44
3.1 DC Transfer Functions 46
3.2 The DC Level and the "Swing" of the Inductor Current Waveform 47
3.3 Defining the AC, DC, and Peak Currents 50
3.4 Understanding the AC, DC and Peak Currents 52
3.5 Defining the "Worst-case" Input Voltage 54
3.6 The Current Ripple Ratio r 57
3.7 Relating r to the Inductance 58
3.8 The Optimum Value of r 59
3.9 Do We Mean Inductor? or Inductance? 60
3.10 How Inductance and Inductor Size Depend on Frequency 61
3.11 How Inductance and Inductor Size Depend on Load Current 62
3.12 How Vendors Specify the Current Rating of an Off-the-shelf Inductor and How to Select it 62
3.13 What is the Inductor Current Rating We Need to Consider for a Given Application? 64
3.14 The Spread and Tolerance of the Current Limit 67
3.15 Worked Example (1) 70
3.16 Worked Examples (2, 3, and 4) 82
3.17 Worked Example (5)—When Not to Increase the Number of Turns 87
3.18 Worked Example (6)—Characterizing an Off-the-shelf Inductor in a Specific Application 92
3.19 Calculating the "Other" Worst-case Stresses 99
Chapter 4: Control Circuits 108
4.1 Basic Control Circuits 109
4.2 The Error Amplifier 112
4.3 Error Amplifier Compensation 113
4.4 A Representative Voltage Mode PWM Controller 117
4.5 Current Mode Control 122
4.6 A Representative Current Mode PWM Controller 124
4.7 Charge Pump Circuits 128
4.8 Multiple Phase PWM Controllers 131
4.9 Resonant Mode Controllers 131
Chapter 5: Non-isolated Circuits 132
5.1 General Design Method 133
5.2 Buck Converter Designs 133
5.3 Boost Converter Designs 142
5.4 Inverting Designs 148
5.5 Step Up/Step Down (Buck/Boost) Designs 152
5.6 Charge Pump Designs 156
5.7 Layout Considerations 160
Chapter 6: Transformer-isolated Circuits 164
6.1 Feedback Mechanisms 165
6.2 Flyback Circuits 172
6.3 Practical Flyback Circuit Design 178
6.4 Off-Line Flyback Example 178
6.5 Non-isolated Flyback Example 185
6.6 Forward Converter Circuits 189
6.7 Practical Forward Converter Design 190
6.8 Off-Line Forward Converter Example 191
6.9 Non-isolated Forward Converter Example 195
6.10 Push-Pull Circuits 199
6.11 Practical Push-Pull Circuit Design 200
6.12 Half Bridge Circuits 204
6.13 Practical Half Bridge Circuit Design 206
6.14 Full Bridge Circuits 209
Chapter 7: Power Semiconductors 212
7.1 Introduction 212
7.2 Power Diodes and Thyristors 213
7.3 Gate Turn-Off Thyristors 230
7.4 Bipolar Power Transistors 232
7.5 Power MOSFETs 241
7.6 Insulated Gate Bipolar Transistor (IGBT) 252
7.7 MOS Controlled Thyristor (MCT) 254
References 256
Bibliography 258
Chapter 8: Conduction and Switching Losses 262
8.1 Switching a Resistive Load 263
8.2 Switching an Inductive Load 268
8.3 Switching Losses and Conduction Loss 271
8.4 A Simplified Model of the MOSFET for Studying Inductive Switching Losses 272
8.5 The Parasitic Capacitances Expressed in an Alternate System 274
8.6 Gate Threshold Voltage 276
8.7 The Turn-on Transition 276
8.8 The Turn-off Transition 279
8.9 Gate Charge Factors 281
8.10 Worked Example 284
8.11 Applying the Switching Loss Analysis to Switching Topologies 288
8.12 Worst-case Input Voltage for Switching Losses 289
8.13 How Switching Losses Vary with the Parasitic Capacitances 290
8.14 Optimizing Driver Capability vis-à-vis MOSFET Characteristics 292
Chapter 9: Power Factor Correction 294
9.1 How Power Factor and Harmonics are Specified 299
9.2 A Universal Input, 180W, Active Power Factor Correction Circuit 301
Chapter 10: Off-line Converter Design and Magnetics 310
10.1 Flyback Converter Magnetics 311
10.2 Forward Converter Magnetics 334
Chapter 11: A "True Sine Wave" Inverter Design Example 360
11.1 Design Requirements 361
11.2 Design Description 361
11.3 Preregulator Detailed Design 367
11.4 Output Converter Detailed Design 371
11.5 H Bridge Detailed Design 373
11.6 Bridge Drive Detailed Design 376
Chapter 12: Thermal Analysis and Design 380
12.1 Developing the Thermal Model 381
12.2 Power Packages on a Heatsink (to-3, to-220, to-218, etc.) 383
12.3 Power Packages Not on a Heatsink (Free Standing) 384
12.4 Radial-leaded Diodes 385
12.5 Surface Mount Parts 386
12.6 Examples of Some Thermal Applications 387
Index 392
A 392
B 392
C 392
D 392
E 393
F 393
G 393
H 393
I 393
J 393
L 393
M 394
N 394
O 394
P 394
R 395
S 395
T 395
V 396
W 396
Z 396