Book Review: Understanding Oscillators (2nd Ed.)

Handbook ofPractical IC Circuits: H. L. HELMS (Prentice-Hall, 1987,163 pp., £41) My first reaction to this book was how could a slim volume, such as this common-or-garden 'technician-level cookbook' [author's quotation] of integrated circuits (lCs) possibly retail at £41? I suspect that very few will be bought, because there are so many similar books on the market at a fraction of the price. In fact, a large amount of the information contained within its covers could be obtained 'free' from manufacturers' catalogues, data sheets and application notes! The book contains six chapters in all, as follows: Chapter 1 is an introduction to integrated circuits. It gives very basic information, the most useful of which I found to be a table ifIC manufacturer prefix letters. Chapter 2 deals with operational amplifier circuits. After describing the usual basic circuits, such as the inverting and non-inverting configurations, it gives a few oscillator and active-filter circuits. It then describes a transresistance and a transconductance amplifier which it attempts to analyse. Unfortunately, however, there are several omissions and misprints on the circuit diagrams and a poor analysis. A few more diverse ICs and op. amps. are then described. Chapter 3 deals with popular linear ICs such as 555/556 timers and some of its applications, voltage regulators, voltage-controlled oscillators (YCOs), and the LM565 phase-locked loop (PLL) rc. Chapter 4 deals with TTL digital circuits. It lists the major TTL IC devices (7400 and 74000 series) and gives diagrams of the pin-connections of some of them, plus a few applications, such as frequency dividers and shift registers. Chapter 5 deals with CMOS digital IC circuits. As before, it lists the major CMOS IC devices (4000 series) and gives diagrams of the pin-connections of some of them. It describes some of the precautions to be observed when using CMOS ICs. A few applications, such as a 0-99 counter and a parallel-to-serial converter, are also described. Chapter 6, 'Tying It All Together', discusses the problems involved in combining TTL and CMOS ICs together in the same circuit and the driving of external loads from TTL outputs. The book is produced in an expensive format which is quite inappropriate to the material which it contains. I also found that the Index has certain glaring omissions, a number of key items contained in the text not being listed therein. In summary, I consider this to be a rather ordinary, run-of-the-mill book at a totally exorbitant, unrealistic price! BRIAN M. SHAW, Division of Electrical and Electronic Engineering, Hatfield Polytechnic