This book describes active and passive devices and circuit configurations used for the generation and processing of pulse, digital, and switching waveforms. These nonsinusoidal signals find extensive application in such fields as computers, control systems, counting and timing systems, data-processing systems, digital instrumentation, pulse communications, radar, telemetry, television, and in many areas of experimental research.

Methods are presented for the generation of very narrow (nanosecond or microsecond) pulses and of wider (millisecond or second) gates or square waves. Techniques are also given for the generation of a variety of other waveforms. These include a step, an exponential, a pulse code, a staircase, a precisely linear ramp, etc. Having been generated, a waveform must be processed in some way in order to perform a useful function. For example, it may be necessary to transmit the signal from one location to another, to amplify it, to select a portion of it in voltage, to choose a section of it in time, to combine it with other signals in order to perform a logic operation, to use it to synchronize a system, and so forth. All these processes are studied in detail in this text.

The book begins with a review of those topics in electronic circuit theory which will be most useful throughout the text. The first section defines a uniform system of notation which is equally applicable to transistors and tubes and which differs in a minimal way from present standards. The reader, after becoming acquainted with this notation, may wish temporarily to omit the rest of the first chapter. He may, instead, prefer to review each selected topic individually when a reference is made to it at a later point in the text. The subjects covered in Chapter 1 include network theorems, the small-signal equivalent circuits of tubes and transistors (including the correlation between transistor low-frequency h parameters and the high-frequency hybrid- circuit elements), some very elementary feedback amplifier considerations, and the graphical methods of analysis. The book then continues with a study of how pulse-type signals are transmitted, shaped, or amplified by linear circuits. Included are resistive, capacitive, and inductive networks (Chapter 2), pulse transformers and delay lines (Chapter 3), and amplifiers (Chapters 4 and 5). A particularly detailed study of transistor wideband amplifiers (including compensation techniques) is made. As background material for the nonlinear wave-shaping circuits which are to follow, an extensive summary of the steady-state switching characteristics of devices is given (Chapter 6). Included are the semiconductor diode, the avalanche diode, the vacuum diode, a lengthy study of the transistor at cutoff and in saturation, the avalanche transistor, and the vacuum tube. Analyses of waveshaping and switching functions which can be performed with nonlinear elements are introduced in the next two chapters: clipping and non-regenerative comparator circuits (Chapter 7) and clamping and switching circuits (Chapter 8). The study of digital operations begins in Chapter 9 with logic circuits, including Boolean algebra. Bistable multivibrators are treated in Chapter 10. The generation of gating signals and square waves by monostable and astable multivibrators is considered in Chapter 11. Negative-resistance devices are treated in Chapter 12. These include the tunnel diode, the unijunction transistor, the four-layer diode, the silicon-controlled switch (and its variants), and the avalanche transistor. Switching Circuits constructed from these negative-resistance devices are discussed in Chapter 13. The next two chapters treat voltage and current time-base generators (including the phantastron circuit, the Miller integrator, and the bootstrap circuit). Chapter 16 discusses the blocking oscillator and includes the multiar configuration. Chapter 17 considers gates for sampling or transmission of signals and introduce the field-effect transistor as an important device for these applications. The next two chapters deal with counting, timing, synchronization, and frequency division. The final chapter (20) treats the transient switching characteristics of diodes and transistors, including the snap-off diode and the hot-carrier diode. The emphasis throughout this chapter is on the charge-control method of analysis.

In summary, this book presents a thorough study of the following basic circuits or techniques: transmission networks, differentiating circuits (including the transmission-line differentiator), clippers (limiters), comparators (discriminators), clampers (d-c restorers), the transistor or tube as a switch, logic circuits (AND, OR, NOT, NAND, diode matrices, etc.), bistable multis (flip-flops), monostable multis (one-shots), astable multis (square-wave generators), negative-resistance devices and circuits, time-base generators, counting, synchronization, and pulse amplification (including transient response and the effects of driving a transistor into saturation). The signals considered range from the very slow (millisecond or longer) to the very fast (nanosecond). Semiconductor and tube circuits are presented side-by-side throughout the text, but with the principal emphasis on transistors. The basic philosophy adopted is to analyse a circuit on a physical basis in order to provide a clear understanding and intuitive feeling for its behavior. Only after the physical analysis is established is mathematics used to express quantitative relationships. It is assumed that the student has a background in mathematics that includes the study of linear differential equations with constant coefficients. In order to avoid distractions from the principal concern of the analysis of electronic circuits, algebraic and other mathematical manipulation has been kept to a minimum. Solutions to differential equations which describe the circuits under study are given without analysis, but the response indicated by these equations has been plotted and studied in detail.

The piecewise linear and continuous model is introduced wherever such an approximation is useful, particularly in a generalized discussion. However, for the most part, real (commercially available) device characteristics are employed. In this way, the reader may become familiar with the order of magnitude of practical device parameters, the variability of these parameters within a given type and with a change in temperature, the effect of the inevitable shunt capacitance in circuits, the consequence of minority-carrier storage in semiconductor devices, the precautions which must be taken when dealing with nanosecond pulses, the effect of input and output impedances and loading on circuit operation, etc. These considerations are of utmost importance to the student or practicing engineer since the circuits to be designed must function properly and reliably in the physical world rather than under hypothetical or ideal circumstances.

There are a large number of examples worked out in the text in detail in order to illustrate how theory may be applied to obtain quantitative results and to emphasize the order of magnitude of the effects under consideration. In addition, the 700 homework problems give the student experience in the analysis and the design of the circuits discussed in the text and of other configurations to perform similar functions. In almost all numerical problems realistic parameter values and specifications have been chosen. Considerable care has been exercised in the development of these problems, which the authors consider an integral and important part of the text.

There are many ways of implementing a pulse or digital system designed to perform a particular function. It is hoped that through a study of this text and through the experience gained from solving a goodly number of problems, the reader will develop familiarity with these circuits and sharpen his creativity and ingenuity so that he can arrive at a fairly optimum implementation of the system under consideration.

To cover all the material in the book requires three semesters, at least one of which should be part of an undergraduate electronics sequence. The instructor has a wide range of topics to choose from, and he need not follow the exact sequence in the book. For example, the two chapters (4 and 5) on wide-band amplifiers may be considered too specialized for an undergraduate program and they may be omitted without particularly disturbing the sequence.

This book was planned originally as a second edition of the authors’ “Pulse and Digital Circuits” (McGraw-Hill Book Company, New York, 1956). However, so much new material has been added and so extensive and thorough have been the revisions that a new title for the present text seems much more reasonable. About half the topics in this book did not appear in the earlier work, and of the material that was presented there, almost every section has been completely rewritten. This very major overhaul has been made necessary by the rapid developments which have taken place recently in this field, and particularly by the shift in emphasis from vacuum tubes to transistors and other semiconductor devices.

It may be of some interest to note that consideration was given to the advisability of splitting this work into two volumes, each of more moderate size. A questionnaire that sought recommendations concerning the division of the material was addressed to a large number of our academic colleagues. The responses were so divergent that there seemed no alternative but to include all of the topics in one volume.

Considerable thought and effort were given to the pedagogy of presentation, to the explanation of circuit behavior, to the use of a consistent system of notation, and to the care with which detailed waveforms and other diagrams have been drawn in order to facilitate the use of this book in self-study. It is hoped that the practicing engineer will find this book of service in updating himself in this field.

The authors are grateful to the many companies who supplied information in the form of device characteristics, application notes, and instrument instruction manuals. The General Electric Company, Fairchild Semiconductor, Hewlett-Packard Company, Philco Corporation, Radio Corporation of America, Raytheon Company, Tektronix, Inc., Texas Instruments, Inc., and Transitron Electronic Corporation were particularly helpful.

We are pleased to acknowledge our indebtedness to our colleagues at Columbia University, at The City College, and in industry for many fruitful discussions. In particular, the following persons read various portions of the manuscript and offered a great deal of constructive criticism: G. J. Clemens, R. C. Gebhardt, J. Hahn, V. I. Johannes, A. B. Marcovitz, P. T. Mauzey, I. M. Meth, A. C. Ruocchio, and L. Packer. Mr. Mauzey merits our special gratitude because of the many valuable suggestions he offered and because of the diligence with which he assisted in the chore of proofreading.

We express our particular appreciation to Miss S. Silverstein, administrative assistant of the Electrical Engineering Department at The City College, for her most skillful service in the preparation of the manuscript. We also thank W. I. H. Chen, A. B. Glaser, J. T. Millman, and J. N. Taub for their assistance.

JACOB MILLMAN
HERBERT TAUB