This chapter will provide an overview of specialized op amps and their applications. The focus will be on identifying the primary characteristics of the various devices and on illustrating their potential applications.
11.1 PROGRAMMABLE OP AMPS
One class of specialized op amp is the micropower programmable op amp. Such devices utilize an external resistor to establish the quiescent operating current for the internal stages. That is, the internal stages are biased at a particular operating current by the selection of an external resistor. Several characteristics of the amplifier are altered by changes in the programming current (IP):
1. DC supply current
2. Open-loop voltage gain
3. Input bias current