Fundamentals of Power Integrity for Computer Platforms and Systems

Foreword by James L. Knighten xi

Preface xiii

Acknowledgments xv

Acronyms xvii

1 Introduction to Power Integrity 1

1.1 Definition for Power Integrity, 2

1.2 Historical Perspective on Power Integrity Drivers, 3

1.3 First Principles Analysis, 6

1.3.1 Steps to Solve Power Distribution Problems, 7

1.3.2 Limitations in the Analytical and Numerical Process, 9

1.4 Scope of the Text, 13

References, 15

2 Introduction to Platform Power Conversion 16

2.1 Power Distribution System, 17

2.1.1 Centralized and Distributed Distribution Systems, 17

2.1.2 Static Losses in the System Power Path, 18

2.2 Platform DC-to-DC Power Conversion, 21

2.2.1 Popular Converter Types, 22

2.2.2 The Linear Regulator, 22

2.2.3 The Buck Regulator, 26

2.2.4 LC Filter Operation, 32

2.2.5 Power Switch Basics, 34

2.2.6 The Controller, 39

2.2.7 Inductors, 41

2.2.8 Coupled Inductors, 44

2.2.9 Multi-phase Buck Converters, 45

2.2.10 The Tapped-Inductor Buck Converter, 47

2.3 Layout and Noise Considerations, 48

2.4 Summary, 50

References, 51

Problems, 51

3 Review of Electromagnetic Field and Circuit Representations 53

3.1 Vectors and Scalars, 54

3.1.1 Coordinate Systems, 55

3.1.2 Vector Operations and Vector Calculus, 58

3.2 Static Fields, 60

3.2.1 Electrostatics, 60

3.2.2 Magneto-Statics, 68

3.2.3 Conduction and Resistance, 72

3.3 Maxwell's Equations, 74

3.3.1 The Wave Equation, 75

3.3.2 Lossless and Lossy Media, 77

3.4 Useful and Simple Circuit Extractions, 79

3.4.1 "Power Plane" Inductance, 79

3.4.2 Inductance of Two Circular Wires in Space, 80

3.4.3 Resistance between Two Vias in a Power Plane, 83

3.4.4 Notes on Applicability of Formulas, 84

3.5 Summary, 84

References, 85

Problems, 86

4 Power Distribution Network 88

4.1 The Power Distribution Network, 89

4.2 PDN Elements, 94

4.2.1 PCB Network, 95

4.2.2 Socket Distribution, 102

4.2.3 Contact Resistance, 104

4.2.4 Package Distribution, 108

4.2.5 Decoupling Basics and Capacitors, 112

4.3 Impedance Distribution Analysis, 117

4.3.1 Analysis of a PDN Structure through First Principals, 117

4.3.2 Analysis of a Full PDN Structure, 122

4.4 Summary, 127

References, 128

Problems, 129

5 Power Integrity Time-Domain and Boundary Analysis 131

5.1 Source and Load Modeling, 131

5.1.1 Source Representations, 132

5.1.2 Load Representations, 145

5.2 Time-Dependent Systems, 152

5.2.1 Voltage Bus Droop Boundary Conditions, 153

5.2.2 Voltage Bus Droop Boundary Analysis, 154

5.3 Impedance/Load Boundary Analysis, 158

5.4 Summary, 165

References, 166

Problems, 167

6 System Considerations for Power Integrity 168

6.1 Power Loadline Fundamentals, 169

6.1.1 Loadline, 170

6.1.2 Tolerance Band and Voltage Guardband, 172

6.2 Noise Generation Considerations in Power Integrity, 181

6.2.1 Self-generated Power Bus Noise, 181

6.2.2 Coupled Power Bus Noise, 186

6.2.3 Simultaneous Switching Noise, 194

6.3 Power Noise Reduction Techniques, 196

6.4 EMI Considerations for Power Integrity, 199

6.5 Power Integrity PDN in System Measurements, 205

6.6 Summary, 207

References, 208

Problems, 210

7 Silicon Power Distribution and Analysis 211

7.1 Silicon and Package Power Integrity, 212

7.1.1 Silicon Interconnection for Power Distribution, 215

7.1.2 Resistance and Current Density Considerations, 219

7.1.3 PDN Considerations for On-package VR Systems, 226

7.2 Silicon and Package Power Delivery, 232

7.2.1 On-package Power Delivery, 233

7.2.2 Package and On-Silicon Power Delivery Trade-offs, 234

7.3 On-die Decoupling, 237

7.4 Advanced Topics in Power on Silicon, 242

7.5 Summary, 244

References, 245

Problems, 246

Appendix A Table of Inductances for Commonly Used Geometries 247

Appendix B Spherical Coordinate System 250

Appendix C Vector Identities and Formulae 252

Index 255