Introduction and Theory

In this experiment, we study an interesting combination of differential pairs and current mirrors that proves useful in many applications. To arrive at the circuit, let us first address a problem encountered in some cases. Recall that the op amps have a differential input but a single-ended output. Thus, the internal circuits of such op amps must incorporate a stage that “converts” a differential input to a single-ended output. We may naturally consider the topology shown in Figure as a candidate for this task.