ABSTRACT
An analog switch is a useful circuit building block that is capable of performing many different functions in a wide variety of system applications. This chapter looks at some of the systems that use analog switches and the basic functions that switches perform in these systems. The typical (DAS) begins with a multiplexer at the front end to provide input channel selection. A sample-and-hold amplifier follows, a function that “freezes” the analog signal at a constant level, long enough to allow the A/D converter to make an accurate conversion. High speed data acquisition systems find applications in digital signal processing systems such as video frame grabbers and music synthesis/emulation. In these systems, the dynamic properties of the DAS are more important than the DC accuracy. Most modern electronic instruments combine digital control circuits with analog inputs and outputs, and thus analog switches are frequently used in these systems.
