Analog Circuit Design Techniques at 0.5V (eBook)

Preface 7
Contents 8
1 Introduction 11
1.1 Low-voltage analog cir cuit design challenges 14
1.2 Opportunities at low voltages 19
1.3 Organization of the book 24
2 Fully Differential Operational Transconductance Amplifiers (O T As) 26
2.1 Body-input O T A 28
2.2 Gate-input O T A 32
2.3 On-chip biasing circuits for the gate-input O T A 38
2.4 Characterization results for the body-input and gate-input O T A s 44
2.5 Discussion on the two O T A design techniques 48
2.6 Design methodology for low V 50
2.7 Summary 54
3 Weak Inversion MOS Varactors for Tunable Integrators 57
3.1 Brief theoretical overview 58
3.2 Device measur ements and modeling 58
3.3 Circuit applications 64
3.4 Summary 68
4 A 0.5 V 5th-Order Low-Pass Elliptic Filter 69
4.1 Filter topology 69
4.2 On-chip PLL-based automatic frequency tuning loop 70
4.3 Lay out and prototype chip 73
4.4 Characterization Results 74
4.5 Summary 79
5 A 0.5 V Track-and-Hold (T/H) Circuit 84
5.1 Introduction 84
5.2 T/H operation at ultra-low voltages 84
5.3 Fully-differ ential 0.5 V T/H cir cuit 86
5.4 Design details and measurement results 93
5.5 Conclusion 99
6 A 0.5 V Continuous-Time Modulator 103
6.1 Introduction 103
6.2 Return-to-Open DAC 104
6.3 Split RTO DAC Modulator Architecture 109
6.4 Building Block Circuits for 0.5 V Supply 114
6.5 Experimental Results 118
6.6 Conclusions 126
7 0.5 V Receiver Front-End Circuits 127
7.1 Introduction 127
7.2 RF Receiver System-Level Considerations 127
7.3 Low-Noise Amplifiers 128
7.4 Downcon version Mixers 130
7.5 900 MHz Receiver Front-End in 0.18 µ m C M O S 133
A Analysis of a Distributed Model for a MOS Capacitor 146
References 152
Index 160