ANALOG INTEGRATED CIRCUITS FOR COMMUNICATION Principles, Simulation and Design

Transcription

1 ANALOG INTEGRATED CIRCUITS FOR COMMUNICATION Principles, Simulation and Design

2 ANALOG INTEGRATED CIRCUITS FOR COMMUNICATION Principles, Simulation and Design by Donald 0. Pederson University of California and Kartikeya Mayaram Texas Instruments Springer Science+Business Media, LLC

3 Library of Congress Cataloging-in-Publication Data Pederson, Donald O. Analog integrated circuits for communication : principles, simulation and design 1 Donald O. Pederson and Kartikeya Mayaram. p. cm. Includes index. ISBN DOI / ISBN (ebook) 1. Linear integrated circuits. 1. Mayaram, Kartikeya. II. Title. TK7874.P '.S-dc CIP Copyright 1991 by Springer Science+Business Media New York Originally published by Kluwer Academic Publishers in 1991 Softcover reprint ofthe hardcover 1st edition 1991 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher, Springer Science+Business Media, LLC. Printed on acid-jree paper.

4 Contents Preface i x Chapter 1 LARGE-SIGNAL PERFORMANCE OF THE BASIC GAIN STAGES IN ANALOG ICs The Emitter-Coupled Pair The Large-Signal DC Transfer Characteristic of the ECP Distortion Generation and Characterization Large-Signal Circuit Analysis of the ECP Series Expansions to Obtain Distortion Components The Source-Coupled Pair A Series Expansion to Obtain Distortion Components for the SCP ~ Chapter 2 AMPLIFIER POWER SERIES AND DISTORTION General Power Series Description Common-Emitter Stage Example The Ideal C-E Stage with a Large Sinusoidal Input Voltage Power Series and Fourier Series Characterizations The Common-Source MOS Amplifier Stage Intermodulation Distortion 55 Chapter 3 DISTORTION GENERATION WITH SOURCE RESISTANCE AND NONLINEAR BETA Linearization of a Bipolar Stage Due to Source Resistance Distortion Reduction with Source Resistance The ECP with Source Resistance Nonlinear Beta and Distortion Example of Distortion due to Beta(lc) 87 Chapter 4 DISTORTION IN FEEDBACK AMPLIFIERS Effects of Negative Feedback 89 v

5 vi CONTENTS 4.2 Feedback for a General Amplifier 4.3 AC-E Stage with Shunt Feedback 4.4 The C-E Stage with Emitter Feedback 4.5 Alternative Loop-Gain Calculations 4.6 Emitter Feedback in the ECP 4. 7 Internal Feedback in the ECP and the SCP Chapter 5 BASIC IC OUTPUT STAGES 5.1 Requirements for an Output Stage 5.2 The Emitter Follower 5.3 Distortion Calculation using Differential Error 5.4 Power Conversion Efficiency 5.5 The Source Follower 5.6 Push-Pull Emitter Followers 5.7 The Push-Pull Source Follower 5.8 Push-Pull, Single-Polarity Output Stages Chapter 6 TRANSFORMERS 6.1 Introduction 6.2 Elementary Coupled Coils 6.3 Circuit Model for a Transformer 6.4 Inductive Two-Port Parameters 6.5 A Transformer-Coupled, Class-A BIT Output Stage 6.6 Maximum Power Transfer 6.7 Class-A Push-Pull Operation 6.8 Class AB Operation Chapter 7 TUNED CIRCUITS IN BANDPASS AMPLIFIERS 7.1 Introduction 7.2 The Single-Tuned Circuit 7.3 Lowpass Equivalents 7.4 Transformer-Coupled Single-Tuned Circuits 7.5 Single-Tuned, Bandpass Circuits with Loosely Coupled Transformers 7.6 Double-Tuned Stages Chapter 8 SIMPLE BANDPASS AMPLIFIERS Simple Active RC Bandpass Amplifiers An ECP Bandpass Amplifier Synchronous Tuning, Cascading, and Bandwidth Shrinkage 249

6 CONTENTS vii 8.4 Effects of Internal Feedback Multistage Bandpass Design Example Cross Modulation 268 Chapter 9 BASIC ELECTRONIC OSCILLATORS Instabilities, Oscillations and Oscillators The Ideal Electronic Oscillator A Tunnel-Diode Oscillator The van der Pol Approximation Tunnel-Diode Oscillator Example Wien-Type Oscillators Transformer-Coupled ECP Oscillators Transformerless ECP Oscillators 310 Chapter 10 ELECTRONIC OSCILLATORS WITH BIAS-SHIFT LIMITING Bias Shift during Oscillator Buildup in an ECP Oscillator The Basic Oscillator Equation Single-Device, Transformer-Coupled Oscillators Bias Shift and Harmonic Balance Transformer-Coupled MOS Oscillators Squegging Phase-Shift Oscillators The Colpitt's Oscillator Crystal-Controlled Oscillators 365 Chapter 11 RELAXATION AND VOLTAGE-CONTROLLED OSCILLATORS Relaxation-Mode Oscillations Oscillator Graphical Analysis Regenerative Switching in a Relaxation Oscillator Recovery Analysis in a BJT Relaxation Feedback Oscillator Other Astable Oscillators A CMOS Relaxation Oscillator Voltage- and Current -Controlled Oscillators An Astable Schmitt Circuit Equivalence of the Schmitt and Loop-Coupled Bistable Circuits A BJT VCO 405 Chapter 12 ANALOG MULTIPLIERS, MIXERS AND MODULATORS The Emitter-Coupled Pair as a Simple Analog Multiplier 413

7 viii CONTENTS 12.2 A Subtraction Improvement 12.3 Predistortion and Linearity Improvement in the ECP 12.4 The Gilbert Cell 12.5 MOS Analog Multipliers 12.6 Mixing, Modulation and Frequency Translation 12.7 The Fully Balanced (Quad) Mixer 12.8 Single-Device BIT Mixers 12.9 FET Mixers Modulators Chapter 13 DEMODULATORS AND DETECTORS 13.1 AM Demodulation using Analog Multipliers 13.2 Synchronous AM Detection 13.3 Peak Detectors 13.4 Automatic Gain Control 13.5 FM Demodulation, Off-Peak Detection 13.6 Discriminators 13.7 FM Demodulators using Multipliers Chapter 14 PHASE-LOCKED LOOPS 14.1 Basic Configurations and Applications 14.2 A Simple Circuit Model of a PLL 14.3 The Small-Signal Analysis of the PLL 14.4 Dynamics of the PLL in Locked Condition 14.5 The Lock and Capture Ranges 14.6 PLLs with Overdriven PCs and Relaxation Oscillators 14.7 PLL Design Example 14.8 PLL Parameters for a Typical IC Realization 14.9 A PLL Example with a FM input Chapter 15 RECTIAERS,REGULATORSANDVOLTAGEREFERENCES 15.1 Simple Half-Wave Rectifiers 15.2 Full-Wave and Bridge Rectifiers 15.3 Series Regulators 15.4 An Introduction to Switching Regulators 15.5 IC Voltage References Problems Index

8 Preface This book deals with the analysis and design of analog integrated circuits that form the basis of present-day communication systems. The material is intended to be a textbook for class use but should also be a valuable source of information for a practicing engineer. Both bipolar and MOS transistor circuits are analyzed and many numerical examples are used to illustrate the analysis and design techniques developed in this book. A set of problems is presented at the end of the book which covers the subject matter of the whole book. The book has originated out of a senior-level course on nonlinear, analog integrated circuits at the University of California at Berkeley. The material contained in this book has been taught by the first author for several years and the book has been class tested for six semesters. This along with feedback from the students is reflected in the organization and writing of the text. We expect that the students have had an introductory course in analog circuits so that they are familiar with some of the basic analysis techniques and also with the operating principles of the various semiconductor devices. Several important, basic circuits and concepts are reviewed as the subject matter is developed. The approach taken is as follows: first-order analysis techniques are developed first using basic principles and simple device models. Then circuit simulation is used to corroborate the analysis techniques. This procedure provides insight into the operation of circuits and a systematic way of getting an initial design of a circuit. The circuit simulation program SPICE has been extensively used to verify the results of first-order analyses, and for detailed simulations with complex device models. In this manner the student can appreciate the shortcomings of the hand analysis and can resort to simulations when necessary. Simulation results can only be interpreted ix

9 X PREFACE once one has an understanding of how a circuit operates and this is reflected by the manner in which the material is presented. SPICE input files are given for all the circuits that have been analyzed so that the students can quickly duplicate the input file and verify the results. The material contained in this book is covered in a 15-week semester course at the University of California at Berkeley. A chapter-by-chapter summary of the topics covered is given below. Chapter 1 considers the large-signal performance of emitter-coupled pair and source-coupled pair circuits. The concept of harmonic distortion is introduced and series expansions are used as a method for obtaining the distortion components and the results are verified with SPICE simulations. Another technique is introduced in Chapter 2 for computing the distortion components. The transfer characteristic of an amplifier is described by a power series and the harmonic distortion factors are derived. The concept of intermodulation distortion is also developed. In Chapter 3 the distortion modification/generation due to source resistance and nonlinear beta in bipolar transistor circuits is considered. Chapter 4 describes how distortion is modified in feedback amplifiers. The concept of feedback is reviewed and applied to several example circuits with particular attention to establishing correctly the appropriate loop-gain value. Distortion and power transfer calculations in the basic IC output stages are the concern in Chapter 5. Class A, Class B, and Class AB output stages are described. An alternate method for distortion calculation is also presented. Chapter 6 deals with transformers which are essential components in many baseband output stages and which also form the basis for tuned circuits and bandpass amplifiers. The basic low-frequency transformer is developed together with the circuit models and parameters which describe its electrical performance. In this chapter the analysis of transformer-coupled amplifiers and output stages is provided. Tuned circuits are reviewed in Chapter 7. Elementary circuits and evaluation techniques are introduced. Major emphasis is given to circuits employing inductive transformers. The design of simple bandpass amplifiers is considered in Chapter 8. Synchronous tuning, cascading, and bandwidth shrinkage are described and applied to the design of a multistage bandpass amplifier. The concept of cross modulation is also introduced. Chapter 9 describes basic electronic oscillators. Simple and special circuits are used as a basis to provide insight into the design of oscillator circuits. The development is based both on the negative-resistance approach to oscillator analysis as well as the feedback approach.

10 PREFACE xi The concept of bias-shift limiting is introduced in Chapter 10. Steadystate operation of the oscillator corresponds to Class C operation. Single device bipolar and MOS circuits are described. Chapter 11 deals with relaxation and voltage-controlled oscillators. A graphical analysis of the basic oscillator is used to develop ideas that are helpful in understanding the operation and the design of these oscillators. Relaxation oscillator examples in both BJT and MOS technologies are presented and techniques for controlling the period of oscillation are also described leading to voltage (current) controlled oscillators. Analog multipliers, mixers, and modulators are considered in Chapter 12. The emitter-coupled pair is first introduced as a simple analog multiplier and extended to explain the development and operation of a. fourquadrant multiplier. The concepts of mixing and modulation are developed and various examples are given. Chapter 13 deals with demodulators and detectors which form an integral part of any communication circuit. Various techniques for AM and FM demodulation are described. Phase-locked loops which are extensively used as frequency synthesizers and demodulators are examined in Chapter 14. The basic operation of a phase-locked loop is described using macromodels suitable for SPICE simulations. Chapter 15 describes rectifier, regulator, and voltage-reference circuits. Simple rectifier circuits are introduced. The concept of regulation is developed and series and switching regulators are described. The regulator circuits use voltage references and some basic reference circuits are presented. We are pleased to acknowledge the many comments and suggestions provided by our colleagues and students, especially Professor R. G. Meyer. We also appreciate the contributions of Ms. Elizabeth Rhine, Ms. Susie Reynolds, and Ms. Gwyn Horn for their excellent formatting and compositing of the manuscript. Donald 0. Pederson Kartikeya Mayaram

11 ANALOG INTEGRATED CIRCUITS FOR COMMUNICATION Principles, Simulation and Design