The INA165x integrates a supply-divider circuit which may bias the input common-mode voltage and output reference voltage to the halfway point between the applied power supply voltages. The nominal output voltage of the supply divider circuit is shown in Equation 2:
Figure 40 illustrates the internal topology of the supply-divider circuit. The supply divider consists of two 500-kΩ resistors connected between the VCC and VEE pins of the INA165x. The noninverting input of a buffer amplifier is connected to the midpoint of the voltage divider that is formed by the 500-kΩ resistors. The buffer amplifier provides a low-impedance output that is required to bias the REF pins without degrading the CMRR. For dual-supply applications where the supply divider circuit may not be used, no connection is required for the VMID(IN) or VMID(OUT) pins.