Contents
CHAPTER 1
Characteristics and Construction of Printed Wiring Boards 1
1.1 Introduction 1
1.2 Unit System 1
1.3 PWB Construction 2
1.3.1 Resins 3
1.3.2 Alternate Resin Systems 3
1.3.3 Reinforcements 5
1.3.4 Variability in Building Stackups 6
1.3.5 Mixing Laminate Types 7
1.4 PWB Traces 7
1.4.1 Copper Cladding 8
1.4.2 Copper Weights and Thickness 9
1.4.3 Plating the Surface Traces 9
1.4.4 Trace Etch Shape Effects 9
1.5 Vias 10
1.5.1 Via Aspect Ratio 13
1.6 Surface Finishes and Solder Mask 14
1.7 Summary 14
References 15
CHAPTER 2
Resistance of Etched Conductors 17
2.1 Introduction 17
2.2 Resistance at Low Frequencies 17
2.3 Loop Resistance and the Proximity Effect 20
2.3.1 Resistance Matrix 21
2.3.2 Proximity Effect 22
2.4 Resistance Increase with Frequency: Skin Effect 24
2.5 Hand Calculations of Frequency-Dependent Resistance 27
2.5.1 Return Path Resistance 28
2.5.2 Conductor Resistance 28
2.5.3 Total Loop Resistance 29
2.6 Resistance Increase Due to Surface Roughness 29
2.7 Summary 30
Capacitance of Etched Conductors 31
3.1 Introduction 31
3.2 Capacitance and Charge 31
3.2.1 Dielectric Constant 32
3.3 Parallel Plate Capacitor 33
3.4 Self and Mutual Capacitance 35
3.5 Capacitance Matrix 37
3.6 Dielectric Losses 39
3.6.1 Reactance and Displacement Current 40
3.6.2 Loss Tangent 40
3.6.3 Calculating Loss Tangent and Conductance G 41
3.7 Environmental Effects on Laminate εr and Loss Tangent 43
3.7.1 Temperature Effects 44
3.7.2 Moisture Effects 44
3.8 Summary 45
References 45
CHAPTER 4
Inductance of Etched Conductors 47
4.1 Introduction 47
4.2 Field Theory 47
4.2.1 Permeability 48
4.2.2 Inductance 48
4.2.3 Internal and External Inductance 49
4.2.4 Partial Inductance 49
4.2.5 Reciprocity Principal and Transverse Electromagnetic Mode 50
4.3 Circuit Behavior of Inductance 51
4.3.1 Inductive Voltage Drop 53
4.3.2 Inductive Reactance 54
4.4 Inductance Matrix 55
4.4.1 Using the Reciprocity Principle to Obtain the
Inductance Matrix from a Capacitance Matrix 55
4.5 Mutual Inductance 55
4.5.1 Coupling Coefficient 56
4.5.2 Beneficial Effects of Mutual Inductance 57
4.5.3 Deleterious Effects of Mutual Inductance 59
4.6 Hand Calculations for Inductance 60
4.6.1 Inductance of a Wire Above a Return Plane 60
4.6.2 Inductance of Side-by-Side Wires 61
4.6.3 Inductance of Parallel Plates 61
4.6.4 Inductance of Microstrip 63
4.6.5 Inductance of Stripline 63
4.7 Summary 64
References 65
Transmission Lines 67
5.1 Introduction 67
5.2 General Circuit Model of a Lossy Transmission Line 67
5.2.1 Relationship Between ωL andR 70
5.2.2 Relationship Between ωC and G 70
5.3 Impedance 71
5.3.1 Calculating Impedance 72
5.4 Traveling Waves 73
5.4.1 Propagation Constant 74
5.4.2 Phase Shift, Delay, and Wavelength 75
5.4.3 Phase Constant at High Frequencies When R and G Are Small 78
5.4.4 Attenuation 79
5.4.5 Neper and Decibel Conversion 80
5.5 Summary and Worked Examples 82
References 86
CHAPTER 6
Return Paths and Power Supply Decoupling 87
6.1 Introduction 87
6.2 Proper Return Paths 87
6.2.1 Return Paths of Ground-Referenced Signals 89
6.2.2 Stripline 90
6.3 Stripline Routed Between Power and Ground Planes 90
6.3.1 When Power Plane Voltage Is the Same as Signal Voltage 90
6.3.2 When Power Plane Voltage Differs from Signal Voltage 93
6.3.3 Power System Inductance 94
6.4 Split Planes, Motes, and Layer Changes 95
6.4.1 Motes 95
6.4.2 Layer Changes 98
6.5 Connectors and Dense Pin Fields 98
6.5.1 Plane Perforation 99
6.5.2 Antipads 99
6.5.3 Nonfunctional Pads 102
6.5.4 Guidelines for Routing Through Dense Pin Fields 103
6.6 Power Supply Bypass/Decoupling Capacitance 105
6.6.1 Power Supply Integrity 106
6.6.2 Distributed Power Supply Interconnect Model 110
6.7 Connecting to Decoupling Capacitors 112
6.7.1 Via Inductance 112
6.8 Summary 114
References 115
CHAPTER 7
Serial Communication, Loss, and Equalization 117
7.1 Introduction 117
7.2 Harmonic Contents of a Data Stream 117
7.2.1 Line Spectra 119
7.2.2 Combining Harmonics to Create a Pulse 120
7.2.3 The Fourier Integral 122
7.2.4 Rectangular Pulses with Nonzero Rise Times 123
7.3 Line Codes 125
7.4 Bit Rate and Data Rate 126
7.5 Block Codes Used in Serial Transmission 128
7.6 ISI 130
7.6.1 Dispersion 130
7.6.2 Lone 1-Bit Pattern 131
7.7 Eye Diagrams 132
7.8 Equalization and Preemphasis 134
7.8.1 Preemphasis 134
7.8.2 Passive Equalizers 137
7.8.3 Passive RC Equalizer 139
7.9 DC-Blocking Capacitors 140
7.9.1 Calculating the Coupling Capacitor Value 142
7.10 Summary 145
References 146
CHAPTER 8
Single-Ended and Differential Signaling and Crosstalk 149
8.1 Introduction 149
8.2 Odd and Even Modes 149
8.2.1 Circuit Description of Odd and Even Modes 150
8.2.2 Coupling Coefficient 153
8.2.3 Stripline and Microstrip Odd- and Even-Mode Timing 155
8.2.4 Effects of Spacing on Impedance 157
8.3 Multiconductor Transmission Lines 158
8.3.1 Bus Segmentation for Simulation Purposes 159
8.3.2 Switching Behavior of a Wide Bus 160
8.3.3 Simulation Results for Loosely Coupled Lines 161
8.3.4 Simulation Results for Tightly Coupled Lines 162
8.3.5 Data-Dependent Timing Jitter in Multiconductor
Transmission Lines 164
8.4 Differential Signaling, Termination, and Layout Rules 165
8.4.1 Differential Signals and Noise Rejection 165
8.4.2 Differential Impedance and Termination 166
8.4.3 Reflection Coefficient and Return Loss 170
8.4.4 PWB Layout Rules When Routing Differential Pairs 172
8.5 Crosstalk 173
8.5.1 Coupled-Line Circuit Model 175
8.5.2 NEXT and FEXT Coupling Factors 177
8.5.3 Using Kb to Predict NEXT 178
8.5.4 Using Kf to Predict FEXT 179
8.5.5 Guard Traces 179
8.5.6 Crosstalk Worked Example 180
8.5.7 Crosstalk Summary 182
8.6 Summary 182
References 183
CHAPTER 9
Characteristics of Printed Wiring Stripline and Microstrips 185
9.1 Introduction 185
9.2 Stripline 185
9.2.1 Time of Flight 186
9.2.2 Impedance Relationship Between Trace Width,
Thickness, and Plate Spacing 187
9.2.3 Mask Biasing to Obtain a Specific Impedance 189
9.2.4 Hand Calculation of Zo 189
9.2.5 Stripline Fabrication 191
9.3 Microstrip 193
9.3.1 Exposed Microstrip 194
9.3.2 Solder Mask and Embedded Microstrip 196
9.4 Losses in Stripline and Microstrip 197
9.4.1 Dielectric Loss 199
9.4.2 Conductor Loss 199
9.5 Microstrip and Stripline Differential Pairs 201
9.5.1 Broadside Coupled Stripline 201
9.5.2 Edge-Coupled Stripline 204
9.5.3 Edge-Coupled Microstrip 205
9.6 Summary 206
References 207
CHAPTER 10
Surface Mount Capacitors 209
10.1 Introduction 209
10.2 Ceramic Surface Mount Capacitors 209
10.2.1 Dielectric Temperature Characteristics Classification 209
10.2.2 Body Size Coding 211
10.2.3 Frequency Response 212
10.2.4 Inductive Effects: ESL 214
10.2.5 Dielectric and Conductor Losses: ESR 215
10.2.6 Leakage Currents: Insulation Resistance 218
10.2.7 Electrical Model 219
10.2.8 MLCC Capacitor Aging 220
10.2.9 Capacitance Change with DC Bias and Frequency 221
10.2.10 MLCC Usage Guidelines 222
10.3 SMT Tantalum Capacitors 223
10.3.1 Body Size Coding 223
10.3.2 Frequency Response 224
10.3.3 Electrical Model 225
10.3.4 Aging 225
10.3.5 Effects of DC Bias, Temperature, and Relative Humidity 225
10.3.6 Failure of Tantalum Capacitors 226
10.3.7 ESR and Self Heating: Voltage and Temperature Derating 227
10.3.8 Usage Guidelines 227
10.4 Replacing Tantalum with High-Valued Ceramic Capacitors 228
References 230
Appendix: Conversion Factors 231
About the Author 233
Index 235
简介:
格式:pdf
大小:2657K
[此贴子已经被作者于2006-2-28 9:00:40编辑过] |