5.1: Introduction
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- 25411
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As we saw in the preceding chapter, a bipolar junction transistor requires a forward-bias of the base-emitter junction and a reverse-bias of the collector-base junction in order to operate properly. One of the prime BJT parameters is the current gain, \(\beta\). It can have a considerable impact on the operation of the circuit. Unfortunately, \(\beta\) also varies with changes in temperature, collector-emitter voltage, etc., and this can lead to circuit instability. In this chapter we shall investigate a variety of circuit topologies to bias the BJT, always with an eye toward stability.