CMOS Integrated Circuit Design for Wireless Power Transfer (eBook)

Preface 6
Contents 8
Chapter 1: Introduction of Wireless Power Transfer 11
1.1 Motivations 11
1.2 Operation Principles, Regulations, and Standards 12
1.2.1 Near-Field and Far-Field Operation 13
1.2.2 Ultrasound Wireless Power Transfer 15
1.2.3 Inductive and Resonant WPT 16
1.2.4 Wireless Charging Standards 16
1.3 Design Perspectives 17
1.3.1 Comparison of Wired and Wireless Power 17
1.3.2 System Overview 18
1.4 Organization of the Book 18
References 20
Chapter 2: Wireless Power Transfer Systems 22
2.1 Introduction 22
2.2 Output Voltage Regulation Schemes 24
2.2.1 Primary Side Non-linear Power Control 25
2.2.2 Reconfigurable Rectifier for Adaptive Output 28
2.2.3 Resonant Regulating Rectifier 30
2.2.4 Reconfigurable Resonant Regulating Rectifiers 32
2.2.5 Pre-rectifier Regulation 34
2.2.6 Multi-Level Single-Inductor Multiple Output Operation 36
2.3 Summary and Discussion 38
References 39
Chapter 3: Analysis of Coupled-Coils 42
3.1 Introduction 42
3.2 Coupled-Coils and Modeling 43
3.2.1 Ideal Transformer 43
3.2.2 Ideal Coupled-Coils 43
3.2.3 T-Model of Coupled-Coils 44
3.2.4 Transformer Model of Coupled-Coils 45
3.2.5 Reflected Impedance Model of Coupled-Coils 46
3.2.6 Link Voltage Gain and Link Efficiency 47
3.2.7 Computing A and eta of the Ideal Coupled-Coils 48
3.2.8 Design-Oriented Analysis of Coupled-Coils with Parasitics 50
3.3 Resonant Coupled-Coils 53
3.3.1 Series-Series Resonant Coupled-Coils 53
3.3.2 Series-Parallel Resonant Coupled-Coils 56
3.4 Summary 59
References 60
Chapter 4: Circuit Design of CMOS Rectifiers 61
4.1 Introduction 61
4.2 Diodes and Diode-Connected Transistors 63
4.3 Comparator-Based Active Rectifiers 67
4.3.1 Delay Compensation Schemes 69
4.3.2 Delay Time Analysis of Active Diodes 75
4.3.3 Biasing Circuits of Active Rectifiers 78
4.3.4 Full-Wave Rectifier Design Examples 80
4.3.4.1 Power Transistor Sizing 82
4.3.4.2 Start-Up Process 83
4.3.4.3 Measurement Results 84
4.3.5 Reconfigurable Rectifier Design Example 91
4.4 DLL-Based Rectifiers 94
4.5 Rectifiers for RF Energy Harvesting 97
4.6 Summary and Discussion 100
References 102
Chapter 5: Linear Regulators for WPT 105
5.1 Introduction 105
5.2 PMOS and NMOS LDO Regulators 107
5.3 Control Loop Design 109
5.3.1 Dominant Pole Considerations 109
5.3.2 Replica Regulator 111
5.3.3 Flipped Voltage Follower 111
5.3.4 Impedance Attenuation Buffer 113
5.3.5 Digitally Controlled LDO Regulator 113
5.4 Design Case Study 114
5.4.1 Design of Tri-Loop LDO Regulator 114
5.4.1.1 Tri-Loop Design 115
5.4.1.2 Buffer Design 116
5.4.1.3 Stability Design 118
5.4.1.4 Load Regulation 122
5.4.1.5 Power Supply Ripple Rejection 122
5.4.1.6 Measurement Results 125
5.4.1.7 Conclusions for the Tri-Loop Design 127
5.4.2 LDO Regulator with Enhanced Super Source Follower 128
5.5 Summary and Discussion 131
References 133
Chapter 6: DC-DC Converters for WPT 135
6.1 Introduction 135
6.2 DC-DC Converter Comparisons 136
6.3 Control Loop Design 138
6.3.1 Loop Design for Inductor-Based Converters 138
6.3.2 Loop Design for SC DC-DC Converters 140
6.4 Architectures of DC-DC Conversion 144
6.4.1 Multiple-Output Converters 144
6.4.2 Layout Strategy for Efficient Power Delivery 144
6.4.3 Cascade Voltage Regulators 146
6.5 Summary 147
References 148
Chapter 7: Power Amplifiers for WPT 150
7.1 Introduction 150
7.1.1 Integration Processes 151
7.1.2 Losses in Switching PAs 151
7.1.2.1 Conduction Loss 152
7.1.2.2 Turn-On Switching Loss 152
7.1.2.3 Turn-Off Switching Loss 153
7.1.2.4 Gate-Drive Loss 153
7.1.3 Zero Voltage (Current) Switching 154
7.2 Class-D PA 154
7.2.1 Operation Conditions 156
7.2.2 ZVS Class-D PA 159
7.3 Class-E PA 160
7.4 Summary and Discussion 162
References 163
Chapter 8: Conclusions and Future Works 165
8.1 Concluding Remarks of the Book 165
8.2 Suggested Future Works 166
References 167