Recently we've been trying out the ADS122c04 in some applications, and recently we've been trying to make some Pyranometer readouts.
Due to a request from the final client, there are no biasing resistors on the differential output and the system is not connected to local grounding.
An example circuit is as follows, note that filter component do not represent the final values:
As far as we're concerned, the differential input reads return close to zero as the input slowly creep from 0V to 1mV in a 5 minute interval, and after that will not show measurements when exposed to voltages as high as 10mV. Yet, measurements will eventually pick a signal and will output correct readings until there's a 0V input again.
Are there any ways to use a circuit without biasing resistors for common mode voltage?