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a voltage amplifier with a differential input and a single-ended output

An operational amplifier (op-amp) is a voltage amplifier with a differential input and a single-ended output.

an amplifier circuit with very high open loop gain and differential inputs which employs external feedback for control of very high open loop gain's transfer function or gain

An operational amplifier is an amplifier circuit with very high open loop gain and differential inputs which employs external feedback for control of very high open loop gain's transfer function or gain.

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a differential amplifier with an extremely high gain

An operational amplifier, when considered as a standalone component, is a differential amplifier with an extremely high gain.

direct-coupled high gain differential amplifier

The operational amplifier is direct-coupled high gain differential amplifier.

the building block of analog electronics

The operational amplifier is the building block of analog electronics.

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differential amplifiers above all

Remember that operational amplifiers are differential amplifiers above all: they're supposed to amplify the difference in voltage between the two input connections and nothing more.

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the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems

The operational amplifier ('op amp') is the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems.

which are certain kind of differential amplifiers

The most extensively used electronic devices are operational amplifiers, which are certain kind of differential amplifiers.

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