How does an operational amplifier (op-amp) work?

An operational amplifier (op-amp) amplifies the difference between its two input signals.

An op-amp is a high-gain voltage amplifier with two inputs and one output. It amplifies the difference between its two input signals, known as the inverting and non-inverting inputs. The output voltage is proportional to the difference between the two inputs, with a gain determined by the op-amp's internal circuitry.

The op-amp's high gain is achieved through the use of multiple stages of amplification, including a differential amplifier, voltage amplifier, and output stage. The differential amplifier amplifies the difference between the two inputs, while the voltage amplifier provides additional gain. The output stage buffers the output signal and provides a low output impedance.

Op-amps can be used in a variety of applications, including as amplifiers, filters, oscillators, and comparators. They are commonly used in audio and signal processing circuits, as well as in instrumentation and control systems.

Op-amps have a number of important characteristics, including input impedance, output impedance, gain bandwidth product, and slew rate. These characteristics determine the op-amp's performance in different applications and must be carefully considered when selecting an op-amp for a particular circuit.