Q7. What is the AD4111/AD41112 current channel's common-mode input?
The absolute input voltage per IINx pin is from AVSS-0.05V to AVDD+0.05V when input buffers are disabled. The maximum current between IINx+ and IINx- for specified performance is +24mA, therefore the upper voltage limit can only be reached if IINx- is biased to a non-zero voltage. Connecting the IIN- pin to AVSS/GND ensures that for the entire current input range the absolute input voltage at each pin is always within specification.