Operational Amplifiers (Op-Amps)

An operational amplifier (Op-Amp) is a differential amplifier that amplifies the difference of voltages applied to its two input terminals (differential input), and provides a single-ended output. The operational amplifier is an extremely efficient and versatile device. Its applications span the broad electronic industry filling requirements for signal conditioning, special transfer functions, analog instrumentation, analog computation, and special systems design.
Originally, the term, “Operational Amplifier,” was used in the computing field to describe amplifiers that performed various mathematical operations. It was found that the application of negative feedback around a high gain DC amplifier would produce a circuit with a precise gain characteristic that depended only on the feedback used. By the proper selection of feedback components, operational amplifier circuits could be used to add, subtract, average, integrate, and differentiate.
An ideal Op-Amp is basically a 3-terminal device that consists of two high impedance inputs, one an Inverting input marked with a negative sign, ("-") and the other a Non-inverting input marked with a positive plus sign ("+").

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