Which OP AMP configuration provides a voltage gain of 1?

The configuration that provides a voltage gain of 1 is known as a voltage follower, also referred to as a buffer. In this configuration, the output voltage directly follows the input voltage. This means that whatever voltage is applied to the input, the output will also be the same, resulting in a gain of exactly 1.

The primary function of the voltage follower is to provide high input impedance and low output impedance, making it an ideal choice for applications where isolation between stages is required without amplification. This characteristic is particularly valuable in scenarios where the signal source might be adversely affected by loading effects from subsequent stages.

In contrast, the other configurations, such as the inverting and noninverting operational amplifier configurations, do not provide a gain of 1. The inverting configuration typically provides a negative gain that is derived from the ratio of feedback and input resistors, while the noninverting configuration provides a positive gain that is greater than or equal to 1, based on the feedback configuration. The differential amplifier also does not inherently provide a gain of 1, as its function is to amplify the difference between two input signals and can be set for varying levels of gain.

Therefore, the voltage follower is distinctly recognized for its unity gain characteristic.