VCM sets the VOUT common-mode voltage by appropriate selection of precision resistors R1, R2, R3, and R4.
If R1 = R3, R2 = R4, and VSHUNT = 0 V, VOUT is given by Equation 8.
If VOUT is connected to the ADC positive input (AINP) and VCM is connected to the ADC negative input (AINN), VCM appears as a common-mode voltage to the ADC. This configuration allows pseudo-differential measurements and uses the maximum dynamic range of the ADC if VCM is set at midsupply (VDD / 2). A resistor divider from VDD to GND followed by a buffer amplifier can be used to generate VCM.