In the earlier stages of integrated circuit design, analog circuits consisted simply of type 741 operational amplifiers, and digital circuits of 7400-type gates. Today's designers must choose from a much larger and rapidly increasing variety of special integrated circuits marketed by a dynamic and creative industry. Only by a proper selection from this wide range can an economical and competitive solution be found to a given problem. For each individual case the designer must decide which parts of a circuit are best implemented by analog circuitry, which by conventional digital circuitry and which sections could be microprocessor controlled. In order to facilitate this decision for the designer who is not familiar with all these subjects, we have arranged the book so as to group the different circuits according to their field of application. Each chapter is thus written to stand on its own, with a minimum of cross-references. To enable the reader to proceed quickly from an idea to a working circuit, we discuss, for a large variety of problems, typical solutions, the applicability of which has been proved by thorough experimental investigation. Our thanks are here due to Prof. Dr. D. Seitzer for the provision of excellent laboratory facilities. The subject is extensive and the material presented has had to be limited. For this reason, we have omitted elementary circuit design, so that the book addresses the advanced student who has some background in electronics, and the practising engineer and scientist.