Differential Amplifier using Transistors

As the name indicates Differential Amplifier is a dc-coupled amplifier that amplifies the difference between two input signals. It is the building block of analog integrated circuits and operational amplifiers (op-amp). One of the important feature of differential amplifier is that it tends to reject or nullify the part of input signals which is common to both inputs. This provides very good noise immunity in a lot of applications. Let's see the block diagram of a differential amplifier. Vi1 and Vi2 are input [...]