We are all imperfect teachers, but we may be forgiven if we have advanced the matter a little, and have done our best. We announce the prologue, and retire; after us better players will come.

—Will Durant

Genesis and Growth of this Textbook

The origins of this classic textbook Pulse, Digital and Switching Waveforms go back to an age earlier than 1940s.

Frederick Emmons Terman, author, teacher, mentor, university administrator, and well known as the father of California’s Silicon Valley, was perhaps the first author to write a comprehensive textbook on Electronics way back in 1932. He graduated from Stanford University in 1920 with major in Chemistry, switched his field to electrical engineering, and received his master’s degree in 1922. After obtaining his doctorate from Massachusetts Institute of Technology in 1924, he joined Stanford University in 1925 and began his work on his first textbook on Radio Engineering. The success of Terman’s books, which had profound effect on his own reputation in electrical engineering, may be traced in part to his choice of subject matter. Professor Terman also functioned as the Consulting Editor for most of the pioneering textbooks published in the McGraw- Hill Electrical and Electronics Engineering Series commencing from early 1930s. We find in Chapter 18 on Wave Shaping, Non-linear Waves and Pulse Techniques a reference to a large body of literature on pulse circuits in the textbook Electronic and Radio Engineering Fourth Edition, by Terman, published by McGraw-Hill, New York, in 1955. Terman was the first person to receive the prestigious IEEE James H.Mulligan, Jr. Education Medal established in 1956. Through this medal, IEEE recognises the importance of the educator’s contribution to the vitality, imagination, and leadership of the members of engineering profession. The award consists of a gold medal, bronze replica, certificate, and honorarium. Significantly, Millman received the same award 14 years later.

The trail blazed by Professor Terman was not allowed to fade away with his death on December 19, 1982 at the age of 82, Professor Jacob Millman being one of the torchbearers. Jacob Millman, born in 1911 in Russia, received Ph.D from the Massachusetts Institute of Technology in 1935. In the annals of Columbia University, the post-war period of 1950s and 60s is treated as the golden era of systems and control theory. Millman taught Electrical Engineering at the City College of New York from 1946 to 1951 and later joined the Electrical Engineering Department of Columbia University in 1952. He was named Chairman of the Department of Electrical Engineering in 1965 and, at his retirement, became the Charles Bachelor Professor Emeritus of Electrical Engineering. Pioneering textbooks by Millman in Electronics, by Ragazzini, G.Franklin, and Jury in sampleddata controls, and by Schwartz and B. Friedland in linear systems made the work of this group known throughout the world.

In 1950, major changes began in electronic circuits. During World War II electronic devices as well as television were entering the consumer market. The number of electronics courses and laboratories were on the rise. Pulse circuits, as described in the MIT Radiation Laboratory series, became a course of study as an alternative means of viewing electron tube circuits. This was later distilled in the book Pulse and Digital Circuits by Jacob Millman and Herbert Taub. With the publication of Pulse and Digital Circuits in 1956, Jacob Millman and Herbert Taub become legends in their own lifetime.

Professor Jacob Millman wrote eight standard textbooks on electronics between 1941 and 1987. All these books were published by McGraw-Hill, New York and all these textbooks were translated into ten foreign languages. The university curriculum of electronics over the entire world has been greatly influenced by these eight books, and at least six generations of engineers and scientists the world over are indebted to Professor Millman whose books laid their foundation in electronics. Jacob Millman received the IEEE James H.Mulligan, Jr. Education Medal in 1970 “for his impact in the areas of electronic devices and circuits through his outstanding textbooks and his stimulating teaching.” Millman died on 23rd May1991 at the age of 80. It is befitting that IEEE has constituted the McGraw-Hill/Jacob Millman Education Award in his honour in 1993. A. Bruce Carlson, Simon Haykin, John G. Proakis, Mathew N.O.Sadiku, and Sanjit K. Mitra are some of the well-known authors among the recipients of this McGraw-Hill/Jacob Millman Education Award.

Herbert Taub, Professor of Electrical Engineering and Physics, received Bachelor of Science degree from the City College of New York and earned his Ph.D. in Physics from Columbia University in New York. He was a Professor in the Electrical Engineering Department at City College, serving as its Chairman for six years. Later, Professor Taub taught Physics at Yeshiva University, also in New York City. He authored several textbooks, the present book with Jacob Millman, on Electrical Engineering. Professor Taub died on 8th February 2003 at the age of 84.

Taub and Schilling wrote in their preface to Digital Integrated Electronics published by McGraw- Hill, New York, in 1977: “In 1956 the McGraw-Hill Book Company published the text Pulse and Digital Circuits co-authored by J. Millman and H. Taub. That book, which undertook to present a rather complete account of the state-of-the-art of digital electronics dealt almost exclusively with vacuum-tube circuits. Semiconductor devices and circuits, which had not long before been introduced, appeared in a single final chapter, added at the last moment, while the book was in production. In the decade that followed semiconductor devices completely supplanted tubes in digital circuitry. In response to this development, the same authors prepared a replacement volume Pulse, Digital and Switching Waveforms, which appeared in 1965. In the newer volume, the overwhelming importance of the semiconductor was appropriately emphasised and vacuum-tube circuits were presented only incidentally. Now, again after about a decade, the advances in integrated circuitry have prompted this present volume. However, this book is intended as a continuation of the 1965 work rather than as a replacement.”

Millman and Taub brought in all the significant developments of pulse circuits in their nascent age and built Pulse and Digital Circuits published by McGraw-Hill, New York, in 1956. In the preface to this textbook, Millman and Taub wrote: “The philosophy of presentation which the authors have adopted has been to analyze a circuit on a physical basis so as to provide a clear understanding and intuitive feeling for its behaviour. Mathematics (through differential equations) is used wherever required but only after the physical motivation behind the mathematics has been discussed. Since this text is intended for a course in electronics and not one in differential equations, the authors feel justified in omitting some of the mathematical details of solution. In most cases the roots of the characteristic equation (the poles of the transfer function) are examined carefully, since these provide a great deal of insight into the nature of the response. Then the analytical solution is written down, the response is plotted, and its physical significance is studied. It is assumed that the reader is familiar with the solution (either by the classical or the Laplace transform method) of linear differential equations with constant coefficients.”

Millman and Taub developed a highly systematic notation, coined new terminology, and enriched the book with their rare pedagogical insights that are laid on a strong mathematical groundwork. The present day authors do not have an easy access to the subject material of 1940s and 1950s. It is noteworthy that the diagrams in Millman-Taub continue to hold their position as standard diagrams, half a century after they first appeared in 1956 in their book Pulse and Digital Circuits. This book is treated as a unified comprehensive summary on pulse circuits employing vacuum tubes. The authors revised this book and added new topics and gave the book a new title Pulse, Digital and Switching Waveforms published by McGraw-Hill, New York, in 1965. Several textbooks were published by publishers of high reputation on this subject in 1960s and early 1970s. Pulse, Digital and Switching Waveforms could withstand the competition of all contemporary books and emerged as a pioneering textbook on this subject. The content of this book still plays a decisive role in planning the academic curricula of undergraduate programmes in most universities across several countries.

Organization of Chapters

The book begins with a review of those topics in electronic circuit theory which will be most useful throughout the text. The reader can prefer to review each selected topic individually when a reference is made to it at a later point in the text. The topics covered in Chapter 1 include network theorems, the small-signal equivalent circuits of transistors, including the correlation between transistor low-frequency h-parameters and the high-frequency hybrid-p 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) and wide band amplifiers. A particular detailed study of transistor wideband amplifiers (including compensation techniques) is made in Chapter 3. As background material for the non-linear waveshaping circuits which are to follow, an extensive summary of the steady-state switching characteristics of devices is given in Chapter 4. Also included are the semiconductor diode, the avalanche diode, a lengthy study of the transistor at cut-off and in saturation, and the avalanche transistor. 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 5) and clamping and switching circuits (Chapter 6). The study of digital operations begins in Chapter 7 with logic circuits including Boolean algebra. Bistable multivibrators are treated in Chapter 8. The generation of gating signals and square waves by monostable and astable multivibrators is considered in Chapter 9. Negative-resistance devices are treated in Chapter 10. These include 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 11. The next two chapters cover voltage and current time-base generators, including the Miller integrator and the bootstrap circuit. Chapter 14 discusses pulse transformers and blocking oscillators. Chapter 15 considers gates for sampling or transmission of signals and introduces 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 treats the transient switching characteristics of diodes and transistors, including the snapoff diode and the hot-carrier diode. The emphasis throughout this chapter is on the charge-control method of analysis.

Revision in this Edition

Conscientious readers of Pulse, Digital and Switching Waveforms by Millman and Taub are aware of its value even 42 years after its publication in 1965. A book of this nature, discussing the basic principles involved in the generation and processing of pulse waveforms, would be of great value to scientists and practising engineers as long as electronics plays a role in science and engineering.

This book has survived for 42 years without any revision while the world of electronics has gone through far-reaching changes. It is our hope that as the content of this publication is revised and interpreted in contemporary electronic devices, this book would continue to play its role in the university curricula as it did in the past.

While revising this classic textbook, I have tried to retain the original flavour and spirit of the book as much as possible, taking care not to rewrite the book in a completely different style. Since the writing style of Millman and Taub is essentially heuristic, I tried to maintain it. Passage of 42 years of time compels additions as well as excisions. I have elaborated on some of the concepts, and presented a more detailed mathematical treatment wherever necessary. The technical jargon of mid 1960’s like “binary”, “multi” are replaced by “bistable multivibrator” and “multivibrator” in chapters on bistable multivibrator (Chapter 8), logic circuits (Chapter 7), and counting and timing (Chapter 16). While dealing with the introductory part of logic circuits, I have introduced terms like byte, nibble, mouse, keyboard, central processing unit (CPU), arithmetic and logic unit (ALU) to make the contents contemporary. I had to take away topics that have become obsolete or irrelevant in the present-day academic scenario.

Additional pedagogical aids have been included in the revised edition with an intention to make the contents of the book accessible to the present generation students. The revision has focussed on the central concepts of Millman-Taub in a more elaborate way, and presented them in an easyto- understand reader-friendly style. New pedagogical features include new completely solved examples, review questions, and practice problems at the end of each chapter. The solutions manual to all exercise problems is made available to instructors on the dedicated website http:// www.mhhe.com/millman/prakashrao/pdsw. Readers would be offered addenda for the book at appropriate times. The references cited in the 1965 edition of this book are indicated throughout this edition in the form of footnotes. The entire list of references can be found in chronological order in the bibliography. These footnotes and the bibliography are intended to offer the reader an insight into the development of this classic textbook during the growing period of electronics.

The main reason for revising Pulse, Digital and Switching Waveforms is to preserve the rich legacy that Millman and Taub left behind for the present and future generations for inspiration and to inculcate a spirit of enquiry.

Mothiki S. Prakash Rao