Question

Discuss briefly regarding the classification of power amplifiers based on the operational modes. Declare the region of the device. [ 10M ]

Answer 1

Answer -

Classification of power amplifier based on the operational modes

On the basis of the mode of operation, the power amplifiers may be classified as follows:

Class A:

The output signal varies for a full 360^o of the input signal.

Class B:

A class B circuit provides an output signal varying over one-half the input signal cycle, or for 180^o of the signal.

Class AB:

An amplifier may be biased at a dc level above the zero bias current level of class B and above one half the supply voltage level of class A; this bias condition is class AB. For class AB operation, the output signal swing occurs between 180^o and 360^o and is neither class A nor class B operation.

Class C:

The output of a class C amplifier is biased for operation at less than 180^o of the cycle and will operate only with a tuned (resonant) ciecuit, which provides a full cycle of operation for the tune or resonant frequency.

Class D:

This operating class is a form of amplifier operation using pulse (digital) signals, which are on for a short interval and off for a longer interval.