In the actual circuit, the feedback network is usually combined to form some functional module.
The operational amplifier is a kind of amplifier with special coupling circuit and feedback.
The output signal can be the result of addition, subtraction or differential, integral and other mathematical operations of the input signal.
Because it was early used in analog computers to achieve mathematical operations, it was named \"operational amplifier\".
An operational amplifier is a circuit unit named from a functional point of view, which can be implemented by discrete devices or in semiconductor chips.
With the development of semiconductor technology, most op-amPs exist in the form of single chips.
There are many kinds of operational amplifiers, which are widely used in the electronics industry.