An isolation amp is a form of differential amplifier that allow measurement of small signals in the presence of a high common mode voltage by providing electrical isolation and an electrical safety barrier. Amplifiers with an isolation barrier allow the front-end of the amplifier to float with respect to common mode voltage to the limit of the barrier’s breakdown voltage, which is often 1,000 volts or more. This action protects the amplifier and the instrument connected to it, while still allowing a reasonably accurate measurement.

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