Operational amplifier

An operational amplifier (often op amp or opamp) is a <a href="/facts/Direct_coupling/1PvjXxLp">DC-coupled</a> <a href="/facts/Electronic_component/F3NBVv4Q">electronic</a> <a href="/facts/Voltage/EN2po6N2">voltage</a> <a href="/facts/Amplifier/pnRgxncC">amplifier</a> with a <a href="/facts/Differential_input/jusjFQKo">differential input</a>, a (usually) <a href="/facts/Single-ended_signaling/u1FAC18z">single-ended</a> output, and an extremely high <a href="/facts/Gain_(electronics)/CWbehg27">gain</a>. Its name comes from its original use of performing <a href="/facts/Mathematical_operations/Yplv602Q">mathematical operations</a> in <a href="/facts/Analog_computers/3NhYoCML">analog computers</a>. 
By using <a href="/facts/Negative_feedback/G9byVgpN">negative feedback</a>, an <a href="/facts/Op_amp_circuits/m7VjdVDl">op amp circuit</a>'s characteristics (e.g. its gain, input and <a href="/facts/Output_impedance/80brK3Cv">output impedance</a>, <a href="/facts/Bandwidth_(signal_processing)/7eMDzfJI">bandwidth</a>, and functionality) can be determined by external components and have little dependence on <a href="/facts/Temperature_coefficient/Ayc1aNdm">temperature coefficients</a> or <a href="/facts/Engineering_tolerance/zRrj34dF">engineering tolerance</a> in the op amp itself. This flexibility has made the op amp a popular building block in <a href="/facts/Analog_circuit/Bnlnfwwv">analog circuits</a>.
Today, op amps are used widely in consumer, industrial, and scientific electronics. Many standard <a href="/facts/Integrated_circuit/fjn6vg7C">integrated circuit</a> op amps cost only a few cents; however, some integrated or hybrid operational amplifiers with special performance specifications may cost over <a href="/facts/United_States_dollar/naEEDUhC">US$</a>100. Op amps may be packaged as <a href="/facts/Electronic_component/F3NBVv4Q">components</a> or used as elements of more complex <a href="/facts/Integrated_circuit/fjn6vg7C">integrated circuits</a>.
The op amp is one type of <a href="/facts/Differential_amplifier/0MWj8eCR">differential amplifier</a>. Other differential amplifier types include the <a href="/facts/Fully_differential_amplifier/sDQELGo1">fully differential amplifier</a> (an op amp with a <a href="/facts/Differential_signalling/jusjFQKo">differential</a> rather than single-ended output), the <a href="/facts/Instrumentation_amplifier/YHtKBL7a">instrumentation amplifier</a> (usually built from three op amps), the <a href="/facts/Isolation_amplifier/HKH3HNan">isolation amplifier</a> (with <a href="/facts/Galvanic_isolation/IMQkwezo">galvanic isolation</a> between input and output), and <a href="/facts/Negative-feedback_amplifier/zQSRBReJ">negative-feedback amplifier</a> (usually built from one or more op amps and a resistive feedback network).

Operational amplifier open-in-new

Operational amplifier