Question

Application of common emitter configuration

Answer 1

The Amplifier is an electronic circuit that is used to increase the strength of a weak input signal in terms of voltage, current, or power. The process of increasing the strength of a weak signal is known as Amplification. One most important constraint during the amplification is that only the magnitude of the signal should increase and there should be no changes in original signal shape. The transistor(BJT, FET)is a major component in an amplifier system. When a transistor is used as an amplifier, the first step is to choose an appropriate configuration, in which device is to be used. Then, the transistor should be biased to get the desired Q-point. The signal is applied to the amplifier input and output gain is achieved. In this article, we will discuss common emitter amplifier analysis.Common Emitter Amplifier ConfigurationIn Common Emitter Amplifier Configuration, the Emitter of a BJT is common to both the input and output signal as shown below. The arrangement is the same for aPNP transistor, but bias will be opposite w.r.t NPN transistor.