The analog inputs of the
ADS921x are intended to be driven differentially. Both AC
coupling and DC coupling of the analog inputs is supported. The analog inputs are
designed for an input common-mode voltage that must be equal to the voltage on the
VCMOUT pin. DC-coupled input signals must have a common-mode voltage that meets the
device input common-mode voltage range.
Figure 7-1 shows an equivalent input network diagram.