How it works
An Operational Amplifier (Op-Amp) is a highly versatile integrated circuit that amplifies the voltage difference between its two input pins. It features a non-inverting input (+), an inverting input (-), and a single output.
An ideal op-amp has infinite input resistance (it draws no current) and infinite open-loop gain. In practice, op-amps are almost always used with "negative feedback," where a portion of the output is routed back to the inverting (-) input. This stabilizes the massive gain and allows the op-amp to perform precise mathematical operations on signals: addition, subtraction, integration, and differentiation.
Op-amps are the fundamental building blocks of analog electronics, used to build audio amplifiers, active filters, sensor signal conditioners, and voltage comparators.