Dobkin / Williams Analog Circuit Design

A Tutorial Guide to Applications and Solutions
1. Auflage 2011
ISBN: 978-0-12-385186-4
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 960 Seiten

Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions will aid systems designers with elegant and practical design techniques that focus on common circuit design challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. - Covers the fundamentals of linear/analog circuit and system design to guide engineers with their design challenges - Based on the Application Notes of Linear Technology, the foremost designer of high performance analog products, readers will gain practical insights into design techniques and practice - Broad range of topics, including power management tutorials, switching regulator design, linear regulator design, data conversion, signal conditioning, and high frequency/RF design - Contributors include the leading lights in analog design, Robert Dobkin, Jim Williams and Carl Nelson, among others

Autoren/Hrsg.

Dobkin, Bob

Williams, Jim

Inhaltsverzeichnis

1;Cover;1
2;Analog Circuit Design;4
3;Copyright;5
4;Dedication;6
5;Contents;10
6;Acknowledgments;14
7;Introduction;15
8;Publisher’s Note;12
9;Foreword;17
10;Part
1 -Power Management;18
10.1;Section 1 -Power Management Tutorials ;20
10.1.1;1 -Ceramic input capacitors cancause overvoltage transients;21
10.1.1.1;Plug in the wall adapter at your own risk;21
10.1.1.2;Building the Test Circuit;21
10.1.1.3;Turning on the switch;22
10.1.1.4;Testing a portable application;22
10.1.1.5;Input voltage transients with different input elements;22
10.1.1.6;Optimizing Input Capacitors;23
10.1.1.7;Conclusion;23
10.1.2;2 -Minimizing switching regulator residue in linear regulator outputs;24
10.1.2.1;Introduction;24
10.1.2.1.1;Switching regulator AC output content;24
10.1.2.1.2;Ripple and spike rejection;25
10.1.2.1.3;Ripple/spike simulator;28
10.1.2.1.4;Linear regulator high frequency rejection evaluation/optimization;29
10.1.2.2;References;31
10.1.3;3 -Power Conditioning for notebook and palmtop systems;35
10.1.3.1;Introduction;35
10.1.3.1.1;LT1432 driver for high efficiency 5V and 3.3V buck regulato
r;35
10.1.3.1.2;Circuit description;36
10.1.3.1.3;BICMOS switching regulator family provides highest step-down efficiencies;37
10.1.3.1.4;Surface mount capacitors for switching regulator applications;39
10.1.3.1.5;High efficiency linear supplies;39
10.1.3.1.6;Power switching with dual high side micropower N-channel MOSFET drivers;40
10.1.3.1.7;LT1121 micropower 150mA regulator with shutdown;41
10.1.3.1.8;Cold cathode fluorescent display driver;41
10.1.3.2;Battery charging;42
10.1.3.2.1;Lead acid battery charger;42
10.1.3.2.2;NiCAD charging;43
10.1.3.2.3;LCD display contrast power supply;44
10.1.3.2.4;A 4-cell NiCad regulator/charger;44
10.1.3.3;Power supplies for palmtop computers;47
10.1.3.3.1;2-Cell input palmtop power supply.circuits;48
10.1.3.3.2;LCD bias from 2 AA cells;48
10.1.3.3.3;4-Cell input palmtop power supply.circuits;48
10.1.3.3.4;A CCFL backlight driver for palmtop.machines;51
10.1.4;4 -2-Wire virtual remote sensing for voltage regulators;52
10.1.4.1;Introduction;52
10.1.4.2;"Virtual" remote sensing;52
10.1.4.3;Applications;53
10.1.4.4;VRS linear regulators;53
10.1.4.5;VRS equipped switching regulators;55
10.1.4.6;VRS based isolated switching supplies;55
10.1.4.7;VRS halogen lamp drive circuit;62
10.1.4.8;References;62
10.1.4.9;Appendix A
A primer on LT4180 VRS operation;66
10.2;Section 2 -Switching Regulator Design;74
10.2.1;5 -LT1070 design manual;76
10.2.1.1;Introduction;76
10.2.1.2;Preface;77
10.2.1.2.1;Smaller versions of the LT1070;77
10.2.1.2.2;Inductance calculations;77
10.2.1.2.3;Protecting the magnetics;78
10.2.1.2.4;New switch current specification;78
10.2.1.2.5;High supply voltages;78
10.2.1.2.6;Discontinuous “oscillations” (ringing);79
10.2.1.3;LT1070 operation;79
10.2.1.4;Pin functions;80
10.2.1.4.1;Input supply (VIN);80
10.2.1.4.2;Ground pin;80
10.2.1.4.3;Feedback pin;80
10.2.1.4.4;Compensation pin (Vc);82
10.2.1.4.5;Output pin;83
10.2.1.5;Basic switching regulator topologies;84
10.2.1.5.1;Buck converter;84
10.2.1.5.2;Boost regulators;85
10.2.1.5.3;Combined buck-boost regulator;86
10.2.1.5.4;'Cuk converter;86
10.2.1.5.5;Flyback regulator;86
10.2.1.5.6;Forward converter;87
10.2.1.5.7;Current-boosted boost converter;87
10.2.1.5.8;Current-boosted buck converter;87
10.2.1.6;Application circuits;88
10.2.1.6.1;Boost mode (output voltage higher than input);88
10.2.1.6.2;Inductor;89
10.2.1.6.3;Output capacitor;90
10.2.1.6.4;Frequency compensation;90
10.2.1.6.5;Current steering diode;90
10.2.1.6.6;Short-circuit conditions;90
10.2.1.7;Negative buck converter;91
10.2.1.7.1;Output divider;91
10.2.1.7.2;Duty cycle;91
10.2.1.7.3;Inductor;91
10.2.1.7.4;Output capacitor;92
10.2.1.7.5;Output filter;92
10.2.1.7.6;Input filter;93
10.2.1.7.7;Frequency compensation;93
10.2.1.7.8;Catch diode;93
10.2.1.8;Negative-to-positive buck-boost converter;93
10.2.1.8.1;Setting output voltage;94
10.2.1.8.2;Inductor;94
10.2.1.8.3;Output capacitor;95
10.2.1.8.4;Current steering diode;95
10.2.1.9;Positive buck converter;95
10.2.1.9.1;Duty cycle limitations;96
10.2.1.9.2;Inductor;97
10.2.1.9.3;Output voltage ripple;97
10.2.1.9.4;Output capacitor;97
10.2.1.9.5;Output filter;97
10.2.1.10;Flyback converter;98
10.2.1.10.1;Output divider;99
10.2.1.10.2;Frequency compensation;99
10.2.1.10.3;Snubber design;99
10.2.1.10.4;Output diode (D1);100
10.2.1.10.5;Output capacitor (C1);101
10.2.1.11;Totally isolated converter;102
10.2.1.11.1;Output capacitors;104
10.2.1.11.2;Load and line regulation;104
10.2.1.11.3;Frequency compensation;105
10.2.1.12;Positive current-boosted buck converter;105
10.2.1.13;Negative current-boosted buck converter;106
10.2.1.14;Negative input/negative output flyback converter;107
10.2.1.15;Positive-to-negative flyback converter;107
10.2.1.16;Voltage-boosted boost converter;108
10.2.1.17;Negative boost converter;109
10.2.1.18;Positive-to-negative buck boost converter;109
10.2.1.19;Current-boosted boost converter;109
10.2.1.20;Forward converter;110
10.2.1.21;Frequency compensation;112
10.2.1.21.1;Check margins;114
10.2.1.21.2;Eliminating start-up overshoot;114
10.2.1.22;External current limiting;114
10.2.1.23;Driving external transistors;116
10.2.1.24;Output rectifying diode;117
10.2.1.25;Input filters;119
10.2.1.26;Efficiency calculations;120
10.2.1.26.1;LT1070 operating current;120
10.2.1.26.2;LT1070 switch losses;121
10.2.1.26.3;Output diode losses;121
10.2.1.26.4;Inductor and transformer losses;121
10.2.1.26.5;Snubber losses;121
10.2.1.26.6;Total losses;121
10.2.1.27;Output filters;121
10.2.1.28;Input and output capacitors;123
10.2.1.29;Inductor and transformer basics;123
10.2.1.29.1;Cores with gaps;124
10.2.1.29.2;Inductor selection process;125
10.2.1.29.3;Transformer design example;127
10.2.1.30;Heat sinking information;130
10.2.1.31;Troubleshooting hints;130
10.2.1.32;Warning;130
10.2.1.33;Subharmonic oscillations;131
10.2.1.34;Inductor/transformer manufacturers;139
10.2.1.35;Core manufacturers;139
10.2.1.36;Bibliography;139
10.2.2;6 -Switching regulators for poets;141
10.2.2.1;Basic flyback regulator;142
10.2.2.2;-48V to 5V telecom flyback regulator;143
10.2.2.3;Fully-isolated telecom flyback regulator;144
10.2.2.4;100W off-line switching regulator;146
10.2.2.5;Switch-controlled motor speed controller;149
10.2.2.6;Switch-controlled peltier reference;149
10.2.2.7;Acknowledgments;150
10.2.3;7 -Step-down switching regulators;159
10.2.3.1;Basic step down circuit;159
10.2.3.2;Practical step-down switching regulator;159
10.2.3.3;Dual output step-down regulator;161
10.2.3.4;Negative output regulators;161
10.2.3.5;Current-boosted step-down regulator;162
10.2.3.6;Post regulation-fixed case;163
10.2.3.7;Post regulation-variable case;163
10.2.3.8;Low quiescent current regulators;163
10.2.3.9;Wide range, high power, high voltage regulator;167
10.2.3.10;Regulated sinewave output DC/AC converter;170
10.2.3.11;References;173
10.2.3.12;Appendix A
Physiology of the LT1074;173
10.2.3.13;Appendix BGeneral considerations for switchingregulator design;175
10.2.3.13.1;Inductor selection;176
10.2.4;8 -A monolithic switching regulator with output noise;186
10.2.4.1;Introduction;186
10.2.4.1.1;Switching regulator "noise";186
10.2.4.1.2;A noiseless switching regulator approach;187
10.2.4.1.3;A practical, low noise monolithic regulator;187
10.2.4.1.4;Measuring output noise;188
10.2.4.1.5;System-based noise "measurement";191
10.2.4.1.6;Transition rate effects on noise and efficiency;191
10.2.4.1.7;Negative output regulator;192
10.2.4.1.8;Floating output regulator;192
10.2.4.1.9;Floating bipolar output converter;192
10.2.4.1.10;Battery-powered circuits;194
10.2.4.1.11;Performance augmentation;194
10.2.4.1.12;Low quiescent current regulator;194
10.2.4.1.13;High voltage input regulator;196
10.2.4.1.14;24V-to-5V low noise regulator;198
10.2.4.1.15;10W, 5V to 12V low noise regulator;199
10.2.4.1.16;7500V isolated low noise supply;200
10.2.4.2;References;202
10.2.4.3;Appendix AA history of low noise DC/DC;202
10.2.4.3.1;History;202
10.2.4.3.2;Measuring noise;206
10.2.4.3.3;Low frequency noise;206
10.2.4.3.4;Preamplifier and oscilloscope selection;206
10.2.4.3.5;Ground loops;209
10.2.4.3.6;Pickup;209
10.2.4.3.7;Poor probing technique;209
10.2.4.3.8;Violating coaxial signal transmission—felony case;210
10.2.4.3.9;Violating coaxial signal transmission— misdemeanor case;211
10.2.4.3.10;Proper coaxial connection path;211
10.2.4.3.11;Direct connection path;212
10.2.4.3.12;Test lead connections;212
10.2.4.3.13;Isolated trigger probe;213
10.2.4.3.14;Trigger probe amplifier;213
10.2.4.3.15;Breadboarding and Layout Considerations;217
10.2.4.3.16;5V to 12V Breadboard;218
10.2.4.3.17;5V to ± 15V breadboard;218
10.2.4.3.18;Demonstration board;218
10.2.4.3.19;Testing ripple rejection;220
10.2.4.3.20;Transformers;222
10.2.4.3.21;Inductors;222
10.2.4.3.22;Hints for lowest noise performance;223
10.2.4.3.23;Noise tweaking;223
10.2.4.3.24;Capacitors;224
10.2.4.3.25;Damper network;224
10.2.4.3.26;Measurement technique;224
10.2.4.3.27;Noise test data;224
10.2.4.3.28;Pot core;225
10.2.4.3.29;ER core;225
10.2.4.3.30;Toroid;227
10.2.4.3.31;E core;227
10.2.4.3.32;Summary;227
10.2.4.3.33;Conclusion;227
10.2.4.3.34;Rectifier reverse recovery;233
10.2.4.3.35;Ringing in clamp Zeners;238
10.2.4.3.36;Paralleled rectifiers;238
10.2.4.3.37;Paralleled snubber or damper caps;238
10.2.4.3.38;Ringing in transformer shield leads;238
10.2.4.3.39;Leakage inductance fields;239
10.2.4.3.40;External air gap fields;239
10.2.4.3.41;Poorly bypassed high speed logic;239
10.2.4.3.42;Probe use with a "LISN"
;239
10.2.4.3.43;Conclusion;240
10.2.4.3.44;Summary;240
10.2.5;9 -Powering complex FPGA-based systems using highly integrated DC/DC Module regulator systems;242
10.2.5.1;Innovation in DC/DC design;242
10.2.5.2;DC/DC Module Regulators: Complete Systems in an LGA Package;242
10.2.5.3;48A from four parallel DC/DC Module regulators;244
10.2.5.4;Start-up, soft-start and current sharing;245
10.2.5.5;Conclusion;245
10.2.6;10 -Powering complex FPGA-based systems•using highly integrated DC/DCµ Module regulator systems;246
10.2.6.1;60W by paralleling four DC/DC µModule regulators;246
10.2.6.2;Thermal performance;246
10.2.6.3;Simple copy and paste layout;247
10.2.6.4;Conclusion;248
10.2.7;11 -Diode Turn-On Time Induced Failures in Switching Regulators;249
10.2.7.1;Introduction;249
10.2.7.2;Diode turn-on time perspectives;249
10.2.7.3;Detailed measurement scheme;249
10.2.7.4;Diode Testing and Interpreting Results;253
10.2.7.5;References;254
10.3;Section 3 -Linear Regulator Design;266
10.3.1;12 -Performance verification of low noise, low dropout regulators;267
10.3.1.1;Introduction;267
10.3.1.2;Noise and noise testing;267
10.3.1.3;Noise testing considerations;267
10.3.1.4;Instrumentation performance verification;267
10.3.1.5;Regulator noise measurement;269
10.3.1.6;Bypass capacitor (CBYP) influence;269
10.3.1.7;Interpreting comparative results;269
10.3.1.8;References;269
10.3.1.9;References;269
10.3.1.9.1;Appendix A
Architecture of a low noise LDO;276
10.3.1.9.1.1;Noise minimization;276
10.3.1.9.1.2;Pass element considerations;276
10.3.1.9.1.3;Dynamic characteristics;277
10.3.1.9.1.4;Bypass capacitance and low noise performance;278
10.3.1.9.1.5;Output capacitance and transient response;278
10.3.1.9.1.6;Ceramic capacitors;278
10.3.1.9.1.7;AC voltmeter types;279
10.3.1.9.1.8;Rectify and average;279
10.3.1.9.1.9;Analog computation;279
10.3.1.9.1.10;Thermal;280
10.3.1.9.1.11;Performance comparison of noise driven AC voltmeters;280
10.3.1.9.1.12;Thermal voltmeter circuit;281
10.4;Section 4 -High Voltage and High Current Applications;284
10.4.1;13 -Parasitic capacitance effects in step-up transformer design;285
10.4.1.1;Brian Huffman;285
10.4.1.1.1;Appendix A;288
10.4.2;14 -High efficiency, high density, PolyPhase converters for high current applications;289
10.4.2.1;Introduction;289
10.4.2.2;How do PolyPhase techniques affect circuit performance?;289
10.4.2.2.1;Current-sharing;290
10.4.2.2.2;Output ripple current cancellation and reduced output ripple voltage;290
10.4.2.2.3;Improved load transient response;292
10.4.2.2.4;Input ripple current cancellation;293
10.4.2.2.5;Input ripple current cancellation;293
10.4.2.3;Design considerations;295
10.4.2.3.1;Selection of phase number;296
10.4.2.3.2;PolyPhase converters using the LTC1629;296
10.4.2.3.3;Layout considerations;296
10.4.2.4;Design example: 100A PolyPhase power supply;298
10.4.2.4.1;Design details;298
10.4.2.4.1.1;MOSFETs;298
10.4.2.4.1.2;Inductors;298
10.4.2.4.1.3;Capacitors;299
10.4.2.4.2;Test results;299
10.4.2.5;Summary;301
10.5;Section 5 -Powering Lasers and Illumination Devices;304
10.5.1;15 -Ultracompact LCD backlight inverters;305
10.5.1.1;Introduction;305
10.5.1.1.1;Limitations and problems of magnetic CCFL transformers;305
10.5.1.1.2;Piezoelectric transformers;305
10.5.1.1.3;Developing a PZT transformer control scheme;306
10.5.1.1.4;Additional considerations and benefits;310
10.5.1.1.5;Display parasitic capacitance and its effects;310
10.5.1.2;References;311
10.5.1.3;Appendix A Piezoelectric transformers;312
10.5.1.3.1;"Good Vibrations";312
10.5.1.3.2;Piezowhat?;312
10.5.1.3.3;Alchemy and black magic;312
10.5.1.3.4;The fun part;313
10.5.1.3.5;A resonant personality;313
10.5.1.3.6;Piezoelectricity;314
10.5.1.3.7;Piezoelectric effect;314
10.5.1.3.8;Axis nomenclature;315
10.5.1.3.9;Electrical-mechanical analogies;315
10.5.1.3.10;Coupling;315
10.5.1.3.11;Electrical, mechanical property changes with load;315
10.5.1.3.12;Elasticity;316
10.5.1.3.13;Piezoelectric equation;316
10.5.1.3.14;Basic piezoelectric modes;316
10.5.1.3.15;Poling;316
10.5.1.3.16;Post Poling;317
10.5.1.3.16.1;Applied voltage;317
10.5.1.3.16.2;Applied force;317
10.5.1.3.16.3;Shear;317
10.5.1.3.17;Piezoelectric benders;317
10.5.1.3.18;Loss;318
10.5.1.3.19;Simplified Piezoelectric Element Equivalent Circuit;318
10.5.1.3.20;Simple stack piezoelectric transformer;318
10.5.1.3.21;Conclusion;322
10.5.2;16 -A thermoelectric cooler temperature•controller for fiber optic lasers;325
10.5.2.1;Introduction;325
10.5.2.2;Temperature Controller Requirements;325
10.5.2.3;Temperature Controller Details;326
10.5.2.4;Thermal Loop Considerations;326
10.5.2.5;Temperature Control Loop Optimization;327
10.5.2.6;Temperature Stability Verification;329
10.5.2.7;Reflected Noise Performance;332
10.5.2.8;References;334
10.5.3;17 -Current sources for fiber optic lasers;336
10.5.3.1;Introduction;336
10.5.3.1.1;Design criteria for fiber optic laser current sources;336
10.5.3.1.2;Detailed discussion of performance issues;336
10.5.3.1.2.1;Required power supply;336
10.5.3.1.2.2;Output current capability;336
10.5.3.1.2.3;Output voltage compliance;336
10.5.3.1.2.4;Efficiency;337
10.5.3.1.2.5;Laser connection;337
10.5.3.1.2.6;Output current programming;337
10.5.3.1.2.7;Stability;337
10.5.3.1.2.8;Noise;337
10.5.3.1.2.9;Transient response;337
10.5.3.1.3;Detailed discussion of laser protection issues;337
10.5.3.1.3.1;Overshoot;337
10.5.3.1.3.2;Enable;337
10.5.3.1.3.3;Output current cl337
10.5.3.1.3.4;Open laser protection;337
10.5.3.1.4;Basic current source;337
10.5.3.1.5;High efficiency basic current source;338
10.5.3.1.6;Grounded cathode current source;339
10.5.3.1.7;Single supply, grounded cathode current source;339
10.5.3.1.8;Fully protected, self-enabled, grounded cathode current source;340
10.5.3.1.9;2.5A, grounded cathode current source;342
10.5.3.1.10;0.001% noise, 2A, grounded cathode current source;344
10.5.3.1.11;0.0025% noise, 250mA, grounded anode current source;346
10.5.3.1.12;Low noise, fully floating output current source;346
10.5.3.1.13;Anode-at-supply current source;347
10.5.3.2;References;349
10.5.3.3;Appendix A
Simulating the laser load;349
10.5.4;18 -Bias voltage and current sense circuits for avalanche photodiodes;355
10.5.4.1;Introduction;355
10.5.4.1.1;Simple current monitor circuits (with problems);356
10.5.4.1.2;Carrier based current monitor;356
10.5.4.1.3;DC coupled current monitor;357
10.5.4.1.4;APD bias supply;358
10.5.4.1.5;APD bias supply and current monitor;359
10.5.4.1.6;Transformer based APD bias supply and current monitor;359
10.5.4.1.7;Inductor based APD bias supply;360
10.5.4.1.8;200µV output noise APD bias supply;362
10.5.4.1.9;Low noise APD bias supply and current monitor;363
10.5.4.1.10;0.02% accuracy current monitor;363
10.5.4.1.11;Digital output 0.09% accuracyµcurrent monitor;364
10.5.4.1.12;Digital output current monitor;364
10.5.4.1.13;Digital output current monitor and APD bias supply;367
10.5.4.2;Summary;367
10.5.4.3;References;370
10.5.4.4;Appendix A
Low error feedback signal derivation
techniques;370
10.5.4.4.1;Divider current error compensationlow—"side"shunt case;370
10.5.4.4.2;Divider current error compensation—"high side"shunt case;371
10.5.4.4.3;Ground loops;372
10.5.4.4.4;Pickup;372
10.5.4.4.5;Poor probing technique;372
10.5.4.4.6;Violating coaxial signal transmission—felony case;372
10.5.4.4.7;Violating coaxial signal transmission— misdemeanor case;373
10.5.4.4.8;Proper coaxial connection path;373
10.5.4.4.9;Direct connection path;373
10.5.4.4.10;Test lead connections;374
10.5.4.4.11;Isolated trigger probe;375
10.5.4.4.12;Trigger probe amplifier;375
10.6;Section 6 -Automotive and Industrial Power Design;384
10.6.1;19 -Developments in battery stack voltage measurement;385
10.6.1.1;The battery stack problem;385
10.6.1.2;Transformer based sampling voltmeter;386
10.6.1.3;Detailed circuit operation;386
10.6.1.4;Multi-cell version;388
10.6.1.5;Automatic control and calibration;388
10.6.1.6;Firmware description;392
10.6.1.7;Measurement details;392
10.6.1.8;Adding more channels;393
10.6.1.9;References;394
11;Part
2 -Data Conversion, Signal Conditioning and High Frequency;408
11.1;Section 1 -Data Conversion ;410
11.1.1;20 -Some techniques for direct digitization of transducer outputs;411
11.1.1.1;Jim Williams;411
11.1.2;21 -The care and feeding of high performance ADCs: get all the bits you paid for;423
11.1.2.1;Introduction;423
11.1.2.2;An ADC has many "inputs";423
11.1.2.3;Ground planes and grounding;423
11.1.2.4;Supply bypassing;424
11.1.2.5;Reference bypassing;425
11.1.2.6;Driving the analog input;425
11.1.2.6.1;Switched capacitor inputs;425
11.1.2.6.2;Filtering wideband noise from the input signal;426
11.1.2.7;Choosing an op 426
11.1.2.8;Driving the convert-start input;426
11.1.2.8.1;Effects of jitter;427
11.1.2.9;Routing the data outputs;428
11.1.2.10;Conclusion;429
11.1.2.10.1;Family features;429
11.1.2.11;High speed A/D converters — world’s best power/speed ratio;423
11.1.3;22 -A standards lab grade 20-bit DAC with 0.1ppm/ºC drift;431
11.1.3.1;Introduction;431
11.1.3.1.1;20-bit DAC architecture;431
11.1.3.1.2;Circuitry details;433
11.1.3.1.3;Linearity considerations;433
11.1.3.1.4;DC performance characteristics;433
11.1.3.1.5;Dynamic performance;433
11.1.3.1.6;Conclusion;435
11.1.3.2;References;435
11.1.3.3;Appendix A
A history of high accuracy digital-toanalog
conversion;435
11.1.3.3.1;Approach and error considerations;437
11.1.3.3.2;Circuitry details;438
11.1.3.3.3;Construction;441
11.1.3.3.4;Results;441
11.1.3.3.5;Acknowledgments;441
11.1.4;23 -Delta sigma ADC bridge measurement techniques;478
11.1.4.1;Introduction;478
11.1.4.2;Low cost, precision altimeter uses direct digitization;479
11.1.4.3;How Many Bits?;479
11.1.4.4;Increasing Resolution with Amplifiers;479
11.1.4.5;How Much Gain?;481
11.1.4.6;ADC Response to Amplifier Noise;481
11.1.4.7;How Many Bits?;482
11.1.4.8;Faster or More Resolution with the LTC2440;483
11.1.4.9;How Many Bits?;484
11.1.4.9.1;Appendix A
Frequency response of an AC excited
bridge;485
11.1.4.9.1.1;RMS vs Peak-to-Peak Noise;486
11.1.4.9.1.2;Psychological Factors;486
11.1.5;24 -1ppm settling time measurement for a monolithic 18-bit DAC;497
11.1.5.1;Introduction;497
11.1.5.2;DAC settling time;497
11.1.5.3;Considerations for measuring DAC settling time;498
11.1.5.4;Sampling based high resolution DAC settling time measurement;499
11.1.5.5;Developing a sampling switch;500
11.1.5.6;Electronic switch equivalents;500
11.1.5.7;Transconductance amplifier based switch equivalent;500
11.1.5.8;DAC settling time measurement method;502
11.1.5.9;Detailed settling time circuitry;503
11.1.5.10;Settling time circuit performance;505
11.1.5.11;Using the sampling-based settling time circuit;505
11.1.5.12;References;507
11.1.5.13;Appendix A
A history of high accuracy
digital-to-analog conversion;508
11.1.5.13.1;Delay compensation;511
11.1.5.13.2;Circuit trimming procedure;511
11.1.5.13.3;Ohm's law;519
11.1.5.13.4;Shielding;520
11.1.5.13.5;Connections;521
11.1.5.13.6;Settling time circuit performance verification;524
11.2;Section 2 -Signal Conditioning;532
11.2.1;25 -Applications for a switched-capacitor instrumentation building block;535
11.2.1.1;Instrumentation amplifier;536
11.2.1.2;Ultrahigh performance instrumentation amplifier;536
11.2.1.3;Lock-in amplifier;537
11.2.1.4;Wide range, digitally controlled, variable gain amplifier;538
11.2.1.5;Precision, linearized platinum RTD signal conditioner;539
11.2.1.6;Relative humidity sensor signal conditioner;540
11.2.1.7;LVDT signal conditioner;541
11.2.1.8;Charge pump F.Vand V.F converters;542
11.2.1.9;12-bit A.D converter;543
11.2.1.10;Miscellaneous circuits;544
11.2.1.11;Voltage-controlled current source—grounded source and load;546
11.2.1.12;Current sensing in supply rails;547
11.2.1.13;0.01% analog multiplier;547
11.2.1.14;Inverting a reference;547
11.2.1.15;Low power, 5V driven, temperature compensated crystal oscillator;547
11.2.1.16;Simple thermometer;547
11.2.1.17;High current, "inductorless,"switching regulator;547
11.2.2;26 -Application considerations and circuits for a new chopper-stabilized op 549
11.2.2.1;Applications;553
11.2.2.2;Standard grade variable voltage reference;553
11.2.2.3;Ultra-precision instrumentation amplifier;553
11.2.2.4;High performance isolation amplifier;554
11.2.2.5;Stabilized, low input capacitance buffer (FET probe);556
11.2.2.6;Chopper-stabilized comparator;557
11.2.2.7;Stabilized data converter;558
11.2.2.8;Wide range V.F converter;558
11.2.2.9;1Hz to 30MHz V.F converter;560
11.2.2.10;16-bit A/D converter;560
11.2.2.11;Simple remote thermometer;563
11.2.2.12;Output stages;563
11.2.2.13;References;566
11.2.3;27 -Designing linear circuits for 5V single supply operation;567
11.2.3.1;Linearized RTD signal conditioner;567
11.2.3.2;Linearized output methane detector;568
11.2.3.3;Cold junction compensated thermocouple signal conditioner;569
11.2.3.4;5V powered precision instrumentation amplifier;570
11.2.3.5;5V powered strain gauge signal conditioner;572
11.2.3.6;"Tachless"motor speed controller;572
11.2.3.7;4-20mA current loop transmitter;574
11.2.3.8;Fully isolated limit comparator;575
11.2.3.9;Fully isolated 10-bit A/D converter;576
11.2.4;28 -Application considerations for an instrumentation lowpass filter;580
11.2.4.1;Description;580
11.2.4.2;Tuning the LTC1062;580
11.2.4.3;LTC1062 clock requirements;581
11.2.4.4;Internal oscillator;582
11.2.4.5;Clock feedthrough;582
11.2.4.6;Single 5V supply operation;583
11.2.4.7;Dynamic range and signal/noise ratio;583
11.2.4.8;Step response and burst response;585
11.2.4.9;LTC1062 shows little aliasing;585
11.2.4.10;Cascading the LTC1062;585
11.2.4.11;Using the LTC1062 to create a notch;587
11.2.4.12;Comments on capacitor types;589
11.2.4.13;Clock circuits;589
11.2.4.14;Acknowledgement;590
11.2.5;29 -Micropower circuits for signal conditioning;591
11.2.5.1;Platinum RTD signal conditioner;591
11.2.5.2;Thermocouple signal conditioner;592
11.2.5.3;Sampled strain gauge signal conditioner;592
11.2.5.4;Strobed operation strain gauge bridge signal conditioner;594
11.2.5.5;Thermistor signal conditioner for current loop application;594
11.2.5.6;Microampere drain wall thermostat;595
11.2.5.7;Freezer alarm;596
11.2.5.8;12-Bit A/D converter;596
11.2.5.9;10-Bit, 100µA A/D converter;598
11.2.5.10;20µs sample-hold;599
11.2.5.11;10kHz voltage-to-frequency converter;600
11.2.5.12;1MHz voltage-to-frequency converter;602
11.2.5.13;Switching regulator;603
11.2.5.14;Post regulated micropower switching regulator;604
11.2.6;30 -Thermocouple measurement;613
11.2.6.1;Introduction;613
11.2.6.2;Thermocouples in perspective;613
11.2.6.3;Signal conditioning issues;615
11.2.6.4;Cold junction compensation;615
11.2.6.5;Amplifier selection;617
11.2.6.6;Additional circuit considerations;617
11.2.6.7;Differential thermocouple amplifiers;618
11.2.6.8;Isolated thermocouple amplifiers;618
11.2.6.9;Digital output thermocouple isolator;622
11.2.6.10;Linearization techniques;623
11.2.6.11;References;629
11.2.6.12;Appendix A
Error sources in thermocouple
systems;629
11.2.7;31 -Take the mystery out of the switched-capacitor filter;631
11.2.7.1;Introduction;631
11.2.7.1.1;Overview;631
11.2.7.1.2;The switched-capacitor filter;631
11.2.7.2;Circuit board layout considerations;632
11.2.7.3;Power supplies;634
11.2.7.4;Input considerations;635
11.2.7.4.1;Offset voltage nulling;635
11.2.7.4.2;Slew limiting;638
11.2.7.4.3;Aliasing;639
11.2.7.5;Filter response;640
11.2.7.5.1;What kind of filter do I use? Butterworth, Chebyshev, Bessel or Elliptic;640
11.2.7.6;Filter sensitivity;644
11.2.7.6.1;How stable is my filter?;644
11.2.7.7;Output considerations;645
11.2.7.7.1;THD and dynamic range;645
11.2.7.7.2;THD in active RC filters;645
11.2.7.7.3;Noise in switched-capacitor filters;645
11.2.7.7.4;Bandpass filters and noise—an illustration;647
11.2.7.8;Clock circuitry;647
11.2.7.8.1;Jitter;647
11.2.7.8.2;Clock synchronization with A/D sample clock;649
11.2.7.8.3;Clock feedthru;649
11.2.7.9;Conclusions;650
11.2.7.10;Bibliography;654
11.2.8;32 -Bridge circuits;655
11.2.8.1;Resistance bridges;655
11.2.8.2;Bridge output amplifiers;655
11.2.8.3;DC bridge circuit applications;656
11.2.8.4;Common mode suppression techniques;656
11.2.8.5;Single supply common mode suppression circuits;659
11.2.8.6;Switched-capacitor based instrumentation amplifiers;662
11.2.8.7;Optically coupled switched-capacitor instrumentation amplifier;663
11.2.8.8;Platinum RTD resistance bridge circuits;664
11.2.8.9;Digitally corrected platinum resistance bridge;665
11.2.8.10;Thermistor bridge;670
11.2.8.11;Low power bridge circuits;670
11.2.8.12;Strobed power bridge drive;672
11.2.8.13;Sampled output bridge signal conditioner;672
11.2.8.14;Continuous output sampled bridge signal conditioner;673
11.2.8.15;High resolution continuous output sampled bridge signal conditioner;674
11.2.8.16;AC driven bridge/synchronous demodulator;676
11.2.8.17;AC driven bridge for level transduction;676
11.2.8.18;Time domain bridge;677
11.2.8.19;Bridge oscillator—square wave output;678
11.2.8.20;Quartz stabilized bridge oscillator;679
11.2.8.21;Sine wave output quartz stabilized bridge oscillator;679
11.2.8.22;Wien bridge-based oscillators;680
11.2.8.23;Diode bridge-based 2.5MHz precision rectifier/AC voltmeter;683
11.2.8.24;References;686
11.2.9;33 -High speed amplifier techniques;696
11.2.9.1;Preface;696
11.2.9.2;Introduction;697
11.2.9.3;Perspectives on high speed design;697
11.2.9.4;Mr. Murphy's gallery of high speed amplifier problems;697
11.2.9.5;Tutorial Section;705
11.2.9.5.1;About Cables, Connectors and Terminations;706
11.2.9.5.2;About Probes and Probing Techniques;707
11.2.9.5.3;About Oscilloscopes;710
11.2.9.5.4;About Ground Planes;714
11.2.9.5.5;About Bypass Capacitors;715
11.2.9.5.6;Breadboarding Techniques;715
11.2.9.5.7;Oscillation;718
11.2.9.6;Applications Section I—Amplifiers;655
11.2.9.6.1;Fast 12-bit digital-to-analog converter (DAC) amplifier;720
11.2.9.6.2;2-Channel Video Amplifier;721
11.2.9.6.3;Simple Video Amplifier;721
11.2.9.6.4;Loop Through Cable Receivers;721
11.2.9.6.5;DC stabilization — summing point technique;721
11.2.9.6.6;DC stabilization — differentially sensed technique;722
11.2.9.6.7;DC stabilization — servo controlled FET input stage;722
11.2.9.6.8;DC stabilization — full differential inputs with parallel paths;723
11.2.9.6.9;DC stabilization — full differential inputs, gain-of-1000 with parallel paths;724
11.2.9.6.10;High Speed Differential Line Receiver;725
11.2.9.6.11;Transformer Coupled Amplifier;726
11.2.9.6.12;Differential Comparator Amplifier with Adjustable Offset;727
11.2.9.6.13;Differential Comparator Amplifier with Settable Automatic Limiting and Offset;728
11.2.9.6.14;Photodiode Amplifier;729
11.2.9.6.15;Fast Photo Integrator;730
11.2.9.6.16;Fiber Optic Receiver;731
11.2.9.6.17;40MHz fiber optic receiver with adaptive trigger;731
11.2.9.6.18;50MHz high accuracy analog multiplier;731
11.2.9.6.19;Power Booster Stage;732
11.2.9.6.20;High Power Booster Stage;734
11.2.9.6.21;Ceramic Bandpass Filters;735
11.2.9.6.22;Crystal Filter;736
11.2.9.7;Applications Section II —Oscillators;736
11.2.9.7.1;Sine Wave Output Quartz Stabilized Oscillator;736
11.2.9.7.2;Sine Wave Output Quartz Stabilized Oscillator with Electronic Gain Control;736
11.2.9.7.3;DC Tuned 1MHz-10MHz Wien Bridge Oscillator;737
11.2.9.7.4;Complete AM radio station;738
11.2.9.8;Applications section III—Data conversion;739
11.2.9.8.1;1Hz–1MHz voltage-controlled sine wave oscillator;739
11.2.9.8.2;1Hz–10MHz V?F Converter;741
11.2.9.8.3;8-bit, 100ns sample-hold;743
11.2.9.8.4;15ns current summing comparator;744
11.2.9.8.5;50MHz adaptive threshold trigger circuit;744
11.2.9.8.6;Fast Time-to-Height (Pulsewidth-to-Voltage) Converter;745
11.2.9.8.7;True RMS wideband voltmeter;747
11.2.9.9; Applications Section Iv —Miscellaneous Circuits
;749
11.2.9.9.1;RF Leveling Loop;749
11.2.9.9.2;Voltage Controlled Current Source;750
11.2.9.9.3;High Power Voltage Controlled Current Source;750
11.2.9.9.4;18ns circuit breaker;751
11.2.9.10;References;752
11.2.9.10.1;Appendix A
ABC’s of probes – Tektronix, Inc;753
11.2.9.10.1.1;ABC's of probes —Tektronix, Inc;753
11.2.9.10.1.2;The vital link in your measurement system;753
11.2.9.10.1.3;Why not use a piece of wire?;753
11.2.9.10.1.4;Benefits of using probes;755
11.2.9.10.1.5;How probes affect your measurements;755
11.2.9.10.1.6;Scope Bandwidth at the Probe Tip?;760
11.2.9.10.1.7;How ground leads affect measurements;761
11.2.9.10.1.8;How probe design affects your measurements;762
11.2.9.10.1.9;Tips on using probes;763
11.2.9.10.1.10;Introduction:;764
11.2.9.10.1.11;Measuring Amplifier Settling Time;771
11.2.9.10.1.12;The Oscillation Problem — Frequency Compensation Without Tears;775
11.2.9.10.1.13;Measuring Probe-Oscilloscope Response;781
11.2.9.10.1.14;An Ultra-Fast High Impedance Probe;783
11.2.9.10.1.15;Additional Comments on Breadboarding;785
11.2.9.10.1.16;FCC licensing and construction permit applications for commerical AM broadcasting stations;811
11.2.9.10.1.17;About Current Feedback;812
11.2.9.10.1.18;Current Feedback Basics;812
11.2.9.10.1.19;High Frequency Amplifier Evaluation Board;814
11.2.9.10.1.20;The contributions of Edsel Murphy to the understanding of the behavior of inanimate objects;816
11.2.9.10.1.21;I. Introduction;817
11.2.9.10.1.22;II. General Engineering;817
11.2.9.10.1.23;III. Mathematics;817
11.2.9.10.1.24;IV. Prototyping and Production;817
11.2.9.10.1.25;V. Specifying;818
11.2.9.11;References*;818
11.2.10;34 -A seven-nanosecond comparator for single supply operation;819
11.2.10.1;Introduction;819
11.2.10.2;The LT1394 —an overview;820
11.2.10.2.1;The rogue's gallery of high speed comparator problems;821
11.2.10.3;Tutorial section;824
11.2.10.3.1;About pulse generators;824
11.2.10.3.2;About cables, connectors and terminations;824
11.2.10.3.3;About probes and probing techniques;825
11.2.10.3.4;About oscilloscopes;829
11.2.10.3.5;About ground planes;832
11.2.10.3.6;About bypass capacitors;833
11.2.10.3.7;Breadboarding techniques;834
11.2.10.4;Applications;835
11.2.10.4.1;Crystal oscillators;835
11.2.10.4.2;Switchable output crystal oscillator;836
11.2.10.4.3;Temperature-compensated crystal oscillator (TXCO);836
11.2.10.4.4;Voltage-controlled crystal oscillator (VCXO);837
11.2.10.4.5;Voltage-tunable clock skew generator;838
11.2.10.4.6;Simple 10MHz voltage-to-frequency converter;839
11.2.10.4.7;Precision 1Hz to 10MHz voltage-to-frequency converter;840
11.2.10.4.8;Fast, high impedance, variable threshold trigger;842
11.2.10.4.9;High speed adaptive trigger circuit;842
11.2.10.4.10;18ns, 500µV sensitivity comparator;843
11.2.10.4.11;Voltage-controlled delay;844
11.2.10.4.12;10ns sample-and-hold;845
11.2.10.4.13;Programmable, sub-nanosecond delayed pulse generator;846
11.2.10.4.14;Fast pulse stretcher;848
11.2.10.4.15;20ns response overvoltage protection circuit;849
11.2.10.5;References;851
11.2.10.6;Appendix A
About level shifts;851
11.2.11;35 -Understanding and applying voltage references;856
11.2.11.1;Essential features;858
11.2.11.2;Reference pitfalls;859
11.2.11.2.1;Current-hungry loads;859
11.2.11.2.2;"NC" pins ;860
11.2.11.2.3;Board leakage;860
11.2.11.2.4;Trim-induced temperature drift;860
11.2.11.2.5;Burn-in;861
11.2.11.2.6;Board stress;861
11.2.11.2.7;Temperature-induced noise;862
11.2.11.3;Reference applications;863
11.2.11.4;Conclusion;864
11.2.11.5;For further reading;864
11.2.11.6;Appendix A Buried Zener: low longterm driftand noise;864
11.2.12;36 -Instrumentation applications for a monolithic oscillator;867
11.2.12.1;Introduction;867
11.2.12.1.1;Clock types;867
11.2.12.1.2;A (very) simple, high performance oscillator;868
11.2.12.1.3;Platinum RTD digitizer;868
11.2.12.1.4;Thermistor-to-frequency converter;869
11.2.12.1.5;Isolated, 3500V breakdown, thermistor-to-frequency converter;870
11.2.12.1.6;Relative humidity sensor digitizer-hetrodyne based;871
11.2.12.1.7;Relative humidity sensor digitizer—charge pump based ;872
11.2.12.1.8;Relative humidity sensor digitizer—time domain bridge based ;873
11.2.12.1.9;40nV noise, 0.05µV/ºC drift, chopped bipolar amplifier ;873
11.2.12.1.10;45nV noise, 0.05µV/ºC drift, chopped FET amplifier ;875
11.2.12.1.11;Clock tunable, filter based sine wave generator;877
11.2.12.1.12;Clock tunable, memory based sine wave generator;877
11.2.12.1.13;Clock tunable notch filter;879
11.2.12.1.14;Clock tunable interval generator with 20 x 106:1 dynamic range ;880
11.2.12.1.15;8-bit, 80µs, passive input, A/D converter ;881
11.2.12.2;References;882
11.2.13;37 -Slew rate verification for wideband amplifiers;885
11.2.13.1;Introduction;885
11.2.13.1.1;Amplifier dynamic response;885
11.2.13.1.1.1;LT1818 Short form specifications;886
11.2.13.1.2;Pulse generator rise time effects on measurement;886
11.2.13.1.3;Subnanosecond rise time pulse generators;887
11.2.13.1.4;360ps rise time pulse generator;887
11.2.13.1.5;Circuit optimization;888
11.2.13.1.6;Refining slew rate measurement;890
11.2.13.2;References;892
11.2.13.3;Appendix A
Verifying rise time measurement
integrity;892
11.2.14;38 -Instrumentation circuitry using RMS-to-DC converters;896
11.2.14.1;Introduction;896
11.2.14.1.1;Isolated power line monitor;896
11.2.14.1.2;Fully isolated 2500V breakdown, wideband RMS-to-DC converter;898
11.2.14.1.3;Low distortion AC line RMS voltage regulator;899
11.2.14.1.4;X1000 DC stabilized millivolt preamplifier;901
11.2.14.1.5;Wideband decade ranged x 1000 preamplifier ;901
11.2.14.1.6;Wideband, isolated, quartz crystal RMS current measurement;902
11.2.14.1.7;AC voltage standard with stable frequency and low distortion;904
11.2.14.1.8;RMS leveled output random noise generator;905
11.2.14.1.9;RMS amplitude stabilized level controller;906
11.2.14.2;References;908
11.2.14.3;Appendix A
RMS-to-DC conversion
Joseph Petrofsky;908
11.2.15;39 -775 nanovolt noise measurement for a low noise voltage reference;913
11.2.15.1;Introduction;913
11.2.15.2;Noise measurement;913
11.2.15.3;Noise measurement circuit performance;914
11.2.15.4;References;917
11.2.15.5;Appendix A
Mechanical and layout considerations;918
11.2.15.6;Appendix BInput capacitor selection procedure;918
11.2.15.7;Appendix CPower, grounding and shieldingconsiderations;919
11.3;Section 3 -High Frequency/RF Design;922
11.3.1;40 -LT5528 WCDMA ACPR, AltCPR and noise measurements;923
11.3.1.1;Introduction;923
11.3.2;41 -Measuring phase and delay errors accurately in I/Q modulators;927
11.3.2.1;Introduction;927
11.3.2.2;Measurements;929
11.3.2.2.1;First measurement—null out the I/Q modulator image signal with normal signal connections (Figure 41.6) ;929
11.3.2.2.2;Second measurement—null out the I/Q modulator image signal with reversed differential baseband signals to the modulator's differential I-channel inputs (Figure 41.7) ;930
11.3.2.2.3;Third measurement—null out the I/Q modulator image signal after reversing the I and Q inputs to the modulator (Figure 41.8) ;930
11.3.2.2.4;Calculation of phase impairments;931
11.3.2.3;Applying the method;932
11.3.2.4;Conclusion;932
12;Subject Index;934