The objective of the book is to provide sufficient background and understanding to enable its readers to design and apply switched capacitor circuits whether these are to be implemented as discrete circuits or by MOS technol­ ogy. Since this is the first book devoted entirely to the subject of switched capacitor circuits, it has no pattern to follow. Fortunately, it was developed in an environment where many of the circuits and concepts it discusses could actually be integrated as MOS integrated circuits. It is hoped that this environment has created a selection process that has enhanced the contents. Switched capacitor circuits provide an example of the influence that technol­ ogy can have on the field of electrical engineering. Only seven years ago, the problem of building analog circuits and systems using standard MOS technology was still unsolved. Although analog circuits and systems were implemented by means of integrated circuit technology, they were neither economical nor competitive. The act of combining analog sampled data techniques with MOS technology has solved this difficulty. As a result, the field of switched capacitor circuits has developed into maturity in a relatively short period of time.