Impedance Meters & Analyzers

0 Preface

1 Impedance Measurement

Impedance 2

ZM Functions 4

Bridge-Type DUT Circuits 6

Divider-Type DUT Circuits 7

Impedance-Meter Range 9

Z_x Equivalent Circuits 12

Mode Drive and Divider Inversion 14

DUT-Circuit Voltage Divider 14

Divider Dynamics 17

2 Non-Aligned DUT Circuits

Classic DUT Circuit 20

Classic DUT-Circuit Dynamics 23

A_ix Transresistance Amplifier 24

SMU-H DUT Circuit 31

SMU-H DUT-Circuit Dynamics 32

3 Phase-Aligned DUT Circuits

Switched-Divider DUT Circuits 35

Switched-Divider DUT-Circuit Dynamics 38

   Reactive-Z_x A_ix Equations 38

   Complex DUT A_ix Equations 42

Op-Amp Current-Source Stability 46

Root-Locus Analysis 48

Feedback SMU-H DUT Circuit 51

Feedback SMU-H Dynamics 53

   Series RL, Shunt RC Divider Responses 53

   Series RC, Shunt RL Divider Responses 55

   Feedback SMU-H Loop Stabilization 57

Feedback SMU-H Output 61

Feedback-SMU-H Divider Amplifier 64

Divider Amplifier Output Impedance 67

Divider Amplifier Output Current 69

Gain-Switched Amplifiers 72

4 Analog Oscillators

Oscillation Criterion 75

Wien-Bridge Oscillator 77

Oscillator Amplitude Control 78

   Oscillator Amplitude Control Loop Dynamics 83

Oscillator Forward-Path Transfer Function 86

Amplitude Detector and Error Amplifier 89

B&K 875A Oscillator 94

Transconductance Multiplier 96

Synthesized-Resistance Amplitude Control 97

Synthesized-Resistance ACL Dynamics 102

Synchronous Sampling Amplitude Detector 104

Quadrature Oscillator 108

5 Digital Sine-Wave Generation

Incremental Sine-Cosine Generation 111

Digital Integration Approximations 113

Incremental Function Simulation 116

DI Amplitude Stability 123

DI Frequency Response 125

Digital Integrators as Logic Circuits 130

Tabular Sine-Wave Generation 134

6 Phase Detection

Phase Comparison 140

Analog-Switch Multipliers 142

Analog-Switch Phase Detectors 145

Quadrature Phase Generation 151

Amplifier Amplitude and Phase Error 154

Phase Detection for Non-Aligned DUT-Circuits 156

Parallel to Series R_x Conversion 159

7 DUT Interface

Series and Shunt Parasitic Elements 162

Drive-Sense Magnetic Coupling 165

Input Capacitance Compensation 167

8 DVM and ZM Integration

Dual-Slope ADCs 169

   Modified Dual-Slope DVMs 170

   Bipolar Modified Dual-Slope ADC 174

Σ-Δ ADCs 176

   S-D RC Constraint for n-Bit Accuracy 179

   S-D Algorithm 180

   Unmatched R_U and R_L 181

Autocalibration 181

Z Meter Monolithic Integration 182

9 Impedance Analyzers

Narrowband and Wideband ZAs 185

ZAW Block Diagram 187

Operating Range 188

Sine Generator 190

DUT Circuit 192

Acquisition Amplifier 192

Amplitude Detector 196

Phase Detector 196

10 ZM Instrument Cores 198

ZM Subsystem Design Alternatives 199

ZM201 Maximum-μC ZM 200

ZM202 Feedback SMU-H DUT ZM 204

   ZM202 SMU-H Loop Stability 208

   ZM202 Phase Detector 212

   ZM202 ±5 V Switching Supply 214

ZM203 Digital Sine, Switched-Divider ZM 216

ZM204 Feedback SMU-H ZM 218

   ZM204 DUT-Circuit Dynamics 221

      DUT Driver 221

      DUT Divider, T_x 222

      DUT-Circuit Amplifiers: A_ix and A_vx 223

      Loop Compensation Design 224

ZM204 Phase Detector 225

ZM205 and ZM206 227

   ZM205 227

   ZM206 232

Closure 235

 242 total pages