chapter  12
Pages 24

Transistors fall into two main classes – bipolar and field effect. They are also classified according to the semiconductor material employed – silicon or germanium, and to their field of application (for example, general purpose, switching, high frequency, and so on). Transistors are also classified according to the application that they are designed for, as shown in Table 12.1 below. Note that these classifications can be combined so that it is possible, for example, to classify a transistor as a ‘low-frequency power transistor’ or as a ‘low-noise high-frequency transistor’.