Transistor Feedback Circuits Unit 3 – Shunt Feedback
UNIT 3 – SHUNT FEEDBACK
UNIT OBJECTIVE
At the completion of this unit, you will be able to describe the effects of shunt feedback on ac
gain, bandwidth, input impedance, and output impedance by using a typical shunt feedback
circuit.
UNIT FUNDAMENTALS
Shunt negative feedback places a portion of an amplifier's output voltage in shunt (parallel) with
the input voltage.
Shunt feedback effectively shunts the input and the output of an amplifier.
For a transistor amplifier without feedback, the gain (A) depends on the transistor ac gain (β).
For the transistor used in this circuit, β can vary from 50 to 300.
Av = β