The devices are configured to monitor the input differential voltage when the input signal gain is set by the external resistor, R_G. The output signal is developed with respect to the voltage on the reference pin, REF. The most common application is where the output is referenced to ground when no input signal is present by connecting the REF pin to ground, as Figure 9-1 shows. In single-supply operation, offsetting the output signal to a precise midsupply level is useful (for example, 2.5 V in a 5-V supply environment). To accomplish this level shift, a voltage source must be connected to the REF pin to level shift the output so that the device can drive a single-supply ADC.

Voltage reference devices are an excellent option for providing a low-impedance voltage source for the reference pin. However, if a resistor voltage divider is used to generate a reference voltage, the voltage must be buffered by an op amp to avoid CMRR degradation.