Transistor Feedback Circuits Unit 5 – Differential Amplifiers
UNIT 5 – DIFFERENTIAL AMPLIFIERS
UNIT OBJECTIVE
At the completion of this unit, you will be able to describe the operation of a differential
amplifier by using ac and dc measurements.
UNIT FUNDAMENTALS
This circuit is a differential amplifier. It has two transistors (Q1 and Q2) with equal gains.
The two emitter resistors (R4A and R4B) are tied together and connect to a common emitter
resistor (R5). R5 sets the circuit operating current, which divides equally between the two
transistors.