2.1 Unity Gain / Voltage Follower

One of the simplest configurations for an operational amplifier is unity gain, also sometimes known as a voltage follower. A unity gain operational amplifier has an output that is equal to the signal applied to the non-inverting input. The inverting input is connected directly to the output of the operational amplifier. This configuration is ideal for full-scale, high-impedance signals that are difficult to directly acquire with an Analog-to-Digital Converter (ADC).

Figure 2-1. Unity Gain Schematic

The output of this circuit can be calculated using the following formula:

V O U T ⁢ =   V I N