An operational amplifier is a very magical thing

Operational amplifiers are commonly referred to as' operational amplifiers', and operational amplifiers are a very magical thing. Because it can amplify the input voltage by tens of thousands of times. The specific theoretical magnification is: 100000 to million times. So the reason why it is called an operational amplifier is because at the beginning, it was mainly applicable to analog operational circuits such as addition, subtraction, differentiation, and integration. So it is called an operational amplifier.

An operational amplifier is an electronic integrated circuit (integrated device) that contains a multi-stage amplification circuit. Its input stage is a differential amplification circuit, which has high input resistance and the ability to suppress zero drift; The intermediate stage mainly performs voltage amplification, with a high voltage amplification factor, and is generally composed of a common emitter amplification circuit; The output pole is connected to the load and has the characteristics of strong load carrying capacity and low output resistance. The application of operational amplifiers is very extensive.

Differential amplification: A differential amplification circuit, also known as a differential amplification circuit, changes the output voltage only when there is a difference in voltage between the two input terminals of the circuit, hence it is called differential. The differential amplifier circuit is evolved from an amplifier circuit that stabilizes the static working point (actual function is to control the static values of voltage and current). The differential amplifier uses many components just for input, which together form the differential amplifier. This can make the input impedance very high and also enhance the anti-interference ability of the circuit. Its impedance can be regarded as infinite, which means that we can equivalent this part to an infinite resistance. Benefit: The benefit of this design is that it does not affect the input signal.