I wan't to use the P-Channel of the PGA900 as universal differential input, in order to measure various sensors other than a resistive bridge e.g. in order to measure a Thermocouple I need to use the T-Channel for the cold-junction compensation, and the P-Channel to measure the Thermocouple.
As the P-Channel differential inputs need at least a 0,3V Common-Mode Offset (Datasheet: 7.3.9 P Gain) I already did experiments using a compensated High Impedance bridge and overlay the differential signal on the bridge output. Although this worked as a first test, it is no option for us.
Thus i wanted to ask, whether you already had a use case that had the same problem and now can suggest a solution that helps overcoming the Common-Mode Offset.
I wan't to use the P-Channel of the PGA900 as universal differential input, in order to measure various sensors other than a resistive bridge e.g. in order to measure a Thermocouple I need to use the T-Channel for the cold-junction compensation, and the P-Channel to measure the Thermocouple.
As the P-Channel differential inputs need a 0,3V Common-Mode Offset (7.3.9 P Gain) we already did experiments using a compensated High Impedance bridge and overlay the differential Signal on the bridge output. Although this worked as a first test, it is no option for us.
Thus i wanted to ask, whether you already had a use case that had the same problem and now can recommend a solution that helps overcoming the Common-Mode Offset.
