LINEAR INTEGRATED CIRCUIT APPLICATIONS

LINEAR INTEGRATED CIRCUIT APPLICATIONS

LINEAR INTEGRATED CIRCUIT APPLICATIONS G.B.Clayton Department of Physics Liverpool Polytechnic M

G. B. Clayton 1975 All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission. First published 1975 Reprinted 1977 (with corrections), 1978 Published by THE MACMILLAN PRESS LTD London and Basingstoke Associated companies in Delhi Dublin Hong Kong Johannesburg Lagos Melboume New York Singapore and Tokyo ISBN 978-0-333-18722-7 ISBN 978-1-349-86163-7 (ebook) DOI 10.1007/978-1-349-86163-7 Typeset in Great Britain by PREFACE LTD Salisbury, Wilts This book is sold subject to the standard conditions of the Net Book Agreement The paperback edition of this book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, re-sold, hired out, or otherwise circulated without the publisher's prior consent in any form of bin ding or cover other than that in which it is published and without a similar condition including this condition being imposed on the sub se quent purchaser

Preface The manufacture of circuits in integrated form dates from about 1959; the technology had its first impact in the field of digital electronics and it is here that the most impressive developments have taken place. It is only comparatively recently, after the general acceptance of the first linear i.c.'s, the operational amplifiers. that manufacturers have turned their efforts to the development of a variety of linear integrated circuit devices. Attention has naturally been directed to the linear devices which lend themselves to an economlc utilisation of the i.c. process because of their potentially large volume production requirements. Both linear and digital i.c.'s simplify the design of electronic systems, they free the engineer from much detailed design work and allow hirn to concentrate on the problems of the total system. In a rapidly expanding subject like electronic measurements there is always a difficulty in keeping in touch with the newer devices and techniques that are available. This book is an attempt to remedy the situation, it highlights those linear integ~ated circuit devices that are likely to be of most use in signal measurement and processing systems and shows how they can be used to perform the functional operations. A practical approach is emphasised throughout the book. This is intended to encourage the reader to try out the devices for hirnself. Linear integrated circuit manufacturers strive to make their products with the greatest possible user convenience. The era of 'plug it in and it plays' has almost arrived. It is now possible, using linear i.c.'s, to build electronic systems to a degree of complexity and precision of operation not formerly possible with discrete component systems. Even in systems formerly implemented using discrete components the use of i.c.'s and modules will invariably be found to provide overall cost/ performance advantages. There are savings in component costs when compared with discrete component designs of equivalent performance. there are also cost savings in assembly, inventory, incoming inspection, maintenance, etc. Performance advantages do not rest only in electrical performance but include mechanical performance, environmental performance (the effect of temperature, humidity-etc.) and reliability performance. The most widely used linear integrated circuit is the operational amplifier;

vi the operational amplifier is likely to remain in the forefront of linear system design for some considerable time, until perhaps the individual i.c.'s in measurement systems are absorbed in large scale integrations of the complete system. The applications of operational amplifiers are many and varied: they have been treated in two other books by the author 1,2. In this book the applications of operational amplifiers as measurement amplifiers and the use of operational amplifiers in active filter circuits are dealt with. The remainder of the book is concerned with the more recently introduced linear integrated circuits, monolithic integrated circuit modulators, four quadrant multipliers, timers, waveform generators and phase locked loops. The book describes the principles underlying the operation of the devices and their applications in performing so me of the functions required in signal measurement and processing systems. Numerical exercises are included at the end of each chapter of the book. The exercises are designed to test comprehension and to give familiarity with design equations and with the order of magnitude of the components that are used in practical device applications. The book should prove useful to both the practising experimental scientist and the undergraduate student in a scientific or engineering discipline. The practical approach which it adopts should serve as a balance to the rather intensive theoretical treatment given in many undergraduate courses in electronic engineering. Acknowledgements are made to the following manufacturers for information provided In their techmcalliterature: Analog Devices, Motorola, Signetics, Burr Brown, Fairchild Semiconductor, R.C.A., Exar, Silicon General. GBe References 1. G.B. Clayton Operational Ampli[iers Butterworth London (1971) 2. G.B. Clayton /!'xperiments with Operational Ampli[iers Macmillan (1975)

Contents I Measurement Circuits 1.1 1.l.l 1.1.2 1.1.3 1.2 1.2.1 1.3 1.4 1.5 1.6 1.6.1 1.6.2 1.6.3 1.7 1.7.1 1.8 1.8.1 1.8.2 1.8.3 Exercises 1 Differential Amplifiers for Measurement Applications 2 One Amplifier Differential Circuit 2 Further Differential Circuits 4 An Integrated Circuit Instrumentation Amplifier 9 Modifying the Output Characteristics of an Instrumentation Amplifier 14 Use of Sense and Reierence Terminals 14 When is a Differential Measurement Amplifier Required? 17 Floating Network Measurements 23 Bridge Read-out Amplifiers 24 Photo-cell Amplifiers 30 Photo-Voltaic Cell Amplifiers 30 Photo-Diode Amplifier 31 Photo-Conductive Cell Amplifier 31 Charge Amplifiers 32 Capacitive Transducer Amplitier 34 Voltage and Current Meter Circuits 39 D.C. Voltage Measurements 40 D.C. Current Measurement 41 A.C. Measurements 44 46 2 Some Signal Processing Applications 52 2.1 2.2 2.3 2.4 2.4.1 2.4.2 2.5 Active Filters Using Operationa1 Amplifiers Low Pass Active Filters High Pass Active Filters Band Pass Active Filters VCVS Band Pass Filter A Negative Inmittance Converter Band Pass Filter Filter Realisations Using Analogue Computer Techniques 52 53 59 62 62 65 69

viii 2.6 2.6.1 2.6.2 2.7 2.7.1 Exercises 2 Band Reject Filters Twin 'T' Band Rejections Filters Practical Considerations Governing the Choice of Q Multipole Filters Different Types of Response Some Filter Designs 3 Monolithic Timing and Waveform Generator Devices 73 76 78 81 82 89 91 3.1 Monolithic Timing Circuits 3.1.1 The 555 Timer, Free running Operation 3.1.2 The 555 Timer, Monostable Operation 3.1.3 Sequential Timing 3.1.4 Keyed Oscillator 3.1.5 Fixed Frequency Variable Duty Cycle Oscillator 3.2 Monolithic Waveform Generators 3.2.1 The 566 Waveform Generator 3.2.2 Single Cycle and Gated Operation of the 566 3.2.3 The 566 Used as a Ramp Generator 3.2.4 Asymmetrical Waveforms with the 566 3.2.5 F.M. Generation with two 566's 3.2.6 The Intersill 8038 Waveform Generator 3.2.7 Frequency Modulation and Frequen~y Sweeping of the 8038 Exercises 3 91 91 96 99 100 101 101 101 105 107 107 109 110 116 117 4 Variable Transconductance Devices 4.1 The Variable Transconductance of a Bipolar Transistor 4.2 Using Variable Transconductance for Gain Contral 4.3 Controlled Gain 1.c. Devices 4.3.1 Controlled Operational Amplifiers 4.3.2 The Gate Controlled, Two Channel, Wide Band Amplifier type MC 1545 4.4 Balanced Modulators 4.4.1 The Balanced Modulator type SG 1402 4.4.2 The Balanced Modulator type MC 1596 4.5 Variable Transconductance Linear Multipliers Exercises 4 119 119 120 125 126 128 128 131 133 136 142

ix 5 Variable Gain Devices - Practical Considerations 5.1 5.2 5.2.1 5.2.2 5.3 5.3.1 5.3.2 Exercises 5 Controlled Operational Amplifiers The Two ChanneI, Gate controlled Wide Band Amplifier, type 1545 Parameter Measurements for the 1545 Device Applications of the 1545 Device Modulator Applications Modulation Processes Modulator Circuits 143 143 148 148 151 155 155 157 164 6 Four Quadrant Linear Multipliers - Practical Considerations and Applications 165 6.1 Practical Multipliers - Departures from Ideal Behaviour 165 6.1.1 Feedthrough and Offsets 168 6.1.2 Scale Factor and Scale Factor Errors 169 6.1.3 Multiplier Non-Linearity 171 6.1.4 Total D.C. Error 173 6.2 Multiplier Test Circuits 173 6.2.1 Basic Circuit Arrangements 176 6.2.2 Measurement of Input Offsets and Bias Currents 177 6.2.3 Measurement of Non-Lineanty 178 6.2.4 Frequency Response Characteristics 179 6.3 Multiplier Applications 180 6.3.1 Squaring, Dividing, Square Rooting 180 6.3.2 Mean Square and Root Mean Square 185 6.3.3 Power Measurement 188 6.3.4 Automatie Level Control Applications 191 6.3.5 Voltage Controlled Quadrature Oscillator 194 6.3.6 Further Computation Circuits 194 6.3.7 Modulator/Demodulator Applications 202 Exercises 6 207 7 Phase Locked Loops 208 7.1 Phase Locked Loop Building Blocks 208 7.2 The Phase Lock Loop Principle 209 7.3 Measurement of Lock and Capture Range - Display of Capture Transient 214

x 7.4 Parameters Determining Lock and Capture Range 221 7.4.1 Phase Detector Conversion Gain K d 221 7.4.2 Low Pass Filter and Amplifier 222 7.4.3 YCO Conversion Gain K o 222 7.5 Dynamic Behaviour of the Locked Loop 224 7.5.1 First Order Loop 227 7.5.2 Second Order Loop 228 7.5.3 Measurement of Dynamic Response 233 7.6 Modifying the Loop Characteristics 236 7.6.1 Reducing the Lock Range of the 565 236 7.6.2 Increasing the ~ock Range of the 565 238 7.7 Phase Locked Loop Applications 239 7.7.1 F.M. Demodulation 240 7.7.2 A.M. Demodulation 241 7.7.3 Phase Modulation 242 7.7.4 Frequency Synthesis 242 7.7.5 Frequency Translation 244 Exercises 7 246 Appendix 248 Answers to Exercises 261 Index 265