Page 977 - Basic Electrical Engineering

Again,

14.7.3 Transistor Configurations

A transistor has three terminals. For the connection of input and output, one

of the transistor terminals is made common, e.g., the base terminal can be
made common to both input and output terminal connections. Similarly, the

emitter or the collector can be connected in common configurations. That is
how we get three types of configurations, namely (i) common-base

configuration; (ii) common-emitter configuration; and (iii) common-collector
configuration.
These three types of connections can be made for both n–p–n and p–n–p

transistors.
Each type of configuration has its advantages and disadvantages. These

configurations have been illustrated in Fig. 14.18. The common emitter
configuration is widely used because of its very high voltage and power gain.

Discussions will therefore be restricted to the common emitter configuration
of a transistor. The characteristics of a transistor in the common emitter

configuration is discussed as follows.

Common-emitter transistor characteristics