The linkage between input and output variables provided

C H A P T E R

Another distinct difference between the analysis of BJT and FET transistors is that the input controlling variable for a BJT transistor is a current level, while for the FET a voltage is the controlling variable. In both cases, however, the controlled vari-able on the output side is a current level that also defines the important voltage lev-els of the output circuit.

The general relationships that can be applied to the dc analysis of all FET am-plifiers are

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6.2 FIXED-BIAS CONFIGURATION

The simplest of biasing arrangements for the n-channel JFET appears in Fig. 6.1. Re-ferred to as the fixed-bias configuration, it is one of the few FET configurations that can be solved just as directly using either a mathematical or graphical approach. Both methods are included in this section to demonstrate the difference between the two philosophies and also to establish the fact that the same solution can be obtained us-ing either method.