Transistor Amplifiers下载

Transistor amplifiers have been written about for well over a half century. Why another book on an old subject? I have three reasons. As a field develops, simplifications and refinements occur and misconceptions are corrected. This is still true for analog circuits. Some important concepts have yet to diffuse broadly, leaving engineers and technicians in the dark about puzzling kinds of circuit behavior. This book brings out some of what is either missing or crowded out of introductory active-circuits textbooks and corrects some misconceptions. It also presents refined ways of thinking about circuits that simplify understanding of them. A fuller engineering development of most of these themes is in my Analog Circuit Design book-set, and in this book, I offer fresh and different ways of thinking about neglected or confusing topics. Second, this book attempts to address a very broad range of readership, from experienced engineers to those aspiring to be engineers, especially astute young pre-university students who are good at math and science. Consequently, the challenge is taken to develop circuits concepts with a minimum of advanced mathematics as such. The mathematical basis for Laplace transforms, differential equations, and most of differential and integral calculus (no less advanced calculus) is not actually needed to think in the complex- frequency domain, which mainly involves complex-number algebra. With a good grasp of algebra and trigonometry, it is amazing how far one can venture into analog circuit design, and in this book I set out to show that implicitly. Books containing advanced circuits engineering almost never present applied calculus needed to do circuit analysis. I have included just enough to bridge the gap for the pre-calculus student yet hopefully not annoyengineers too severely. Consequently, I hope that this book, in part, serves to bridge the gap between hobbyist electronics and engineering literature. The first part is about basic circuits concepts and the remainder is amplifier designs. Third, my previous book-set, while presenting examples, does not do what most other books on analog circuits also do not do: “walk through” amplifier designs at an engineering level of detail as an actual design activity. About a dozen amplifiers are designed in this book, step-by-step, with explanation. By presenting a high level of detail, the reader is offered insight into the sequence of thinking of one engineer. The amount of detail is intended to leave the reader . with little or nothing to puzzle over or be left wondering how various major decisions or derivations were made. Designs in a book cannot start with a blank screen (or piece of paper) if something specific is to be written. Circuits are presented, followed by details on how the parts values are determined. This involves a list of considerations and each is patiently gone through so that the resulting design is of industry-standard quality. Then a prototype is built and its behavior compared with design calculations. In engineering projects, often the two do not agree and for some designs in this book, they also do not and modification is required to refine the design after the incongruities have been pondered. At times the design is right and measurements on the bench are wrong because of instrumentation errors. Oscilloscope probes are capacitive loads and interconnecting cables sometimes require termination. What is missing in the older books is discussion of “mixed- signal” A/D and D/A conversion that interfaces analog to digital circuits. Some of the difficulty in analyzing and designing systems with both is ameliorated with new concepts in how to envision ADC and DAC function, both at low speed and dynamically. I introduce some simplifications and what I believe are improvements in notation and terminology. “AC” and “DC” are ambiguous and obsolete, and the awkward expression “low-frequency ac” was long ago avoided by the thermodynamicists, who call it quasistatic. Overall, the notation should be quite readable to anyone skilled in the art. I maintain the well-established use of upper- and lower-case letters and subscripts for static and incremental quantities, though I abandon the upper-lower case distinction for time and complex-frequency domains, preferring to let the domain variable identify the domain. Finally, the last chapter, which logically would be first, expounds upon engineering and design in itself, topics that might be more interesting after one has acquired experience with them and is ripe for deeper reflection upon their wider meaning. This book is intended to be complementary to my Analog Circuit Design book-set while also enabling newer designers to access it. Even the simpler circuits in this book raise issues that experienced electronics engineers can ponder. I hope that for them, a few useful insights will be added to their already considerable knowledge of transistor amplifiers. Writing this book has done that for me!