This book presents a collection of analog electronic circuits based on the operational amplifier; the workhorse of analog electronics. The discussion is supported by a wealth of practical detail that will enable the reader to speedily select, build, and test a desired circuit. The book is primarily intended to be a practical reference work and readers will discover an extensive and invaluable source of functional and established analog circuits, from integrators and differentiators to logarithmic amplifiers, from filters to instrumentation amplifiers. The circuits are grouped according to function, and the approach is to build up slowly from "textbook" examples toward a series of practical, workable circuits.