Feedback is a widely used technique to improve the characteristics of an imperfect amplifier. A generalized amplifier with negative voltage feedback is shown in figure 3.15.
Figure 3.15: Amplifier with negative voltage feedback.
The overall transfer function (closed-loop gain) can be written as
we may write
If . The transfer function is now independent of the amplifier gain. is the transfer function of a stable resistive network which means that will also be stable.