Advantages of Negative Feedback in amplifiers

Advantages of Negative Feedback

• It is possible to improve important characteristics of four basic amplifier types discussed in section 9.2 by the proper use of negative feedback.

• Normally high input resistance of a voltage amplifier can be made higher.

• Normally low output resistance of a voltage amplifier can be lowered.

• The transfer gain Af of the amplifier with feedback can be stabilized against variations of the h or hybrid-n parameters of the transistor or the parameters of the other active devices used in the amplifier.

• The proper use of negative feedback improves frequency response of the amplifier.

• There is a significant improvement in the linearity of operation of the feedback amplifier compared with that of the amplifier without feedback.

Important Concept

All the advantages mentioned above are obtained at the expense of the gain with feedback, which is lowered in comparison with the transfer gain A of an amplifier without feedback.

Review Question

1. What are the advantages of negative feedback in amplifiers