Practical Benefits:Negative FeedbackMost practical amplifier circuits use negative feedback for the following practical benefits: |
Index Electronics concepts Op-amp concepts Feedback concepts | ||||||
|
Go Back |
Stabilization of Voltage GainOne of the benefits of negative feedback is the stabilization of the voltage gain of an amplifier against changes in the components (e.g., with temperature, frequency, etc. ). If you represent the gain without feedback (the open loop gain) by A0 , then the system gain with negative feedback is where B is the fraction of the output which feeds back as a negative voltage at the input. The extent of this stabilizing influence can be illustrated as follows:
|
Index Electronics concepts Op-amp concepts Feedback concepts | |||
|
Go Back |
Increasing Input Impedance
|
Index Electronics concepts Feedback concepts Reference Simpson Sec 7.2 | ||||||
|
Go Back |
Decreasing Output ImpedanceAs in the approach to input impedance, the effect of negative feedback on output impedance can be obtained by analysis of the equivalent circuit.
|
Index Electronics concepts Feedback concepts Reference Simpson Sec 7.2 | ||
|
Go Back |