The applied negative feedback can improve its performance (gain stability, linearity, frequency response, step response) and reduces sensitivity to parameter variations due to manufacturing or environment. Because of these advantages, many amplifiers and control systems use negative feedback.

Advantages of Negative Feedback to an Amplifier:

• Bandwidth of amplifier increases.

• Noise gets reduced.

• Stability of amplifier increases.

• Decreases frequency distortion.

Negative feedback has several aspects to is. First, it reduces the gain of the circuit. Typical amplifier circuits have very high gain, and then a negative feedback loop is placed around the circuit that lowers the gain to a desired level. 

The major changes that are introduced by negative feedback are:

• Reduced sensitivity to changes in open-loop gain.
• Increases the bandwidth - While open-loop amplifier have high gain, they generally have low bandwidth.
• Increase input impedance and decreases output impedance - Basically makes the amplifier closer to an ideal amplifier
• It Decreases the output noise