Differential Amplifier
A differential amplifier serves to amplify the difference
between tow signals. A differential amplifiers forms the basic stage of an integrated
op-amp with differential inputs.
The circuit diagram of the emitter coupled differential
amplifier is shown in the below fig. it uses two identical npn transistors. The
transistors are connected in CE mode. The emitter bias is used here. The two
inputs V1 and V2 and the output is Vo. The
output is derived from the two collector points.