Hello,
Our customer has a question how COM pin should be handled at single ended operation. even he knows COM pin must be connected to GND but did not understand "-IN" description in Table 2.
Could you please help him out the reason or meaning "COM=-IN" in the Table 2, SD=1.
Best regards,
Hello,
The ADS7830 can be used a single ended device, with 8 channels, or it can be used as a pseudo differential input, with 4 channels.
Pseudo differential is a limited version of differential inputs, as the negative input "-in" can only be +/- 200mV from the ground.
In the case of Table 2 in the datasheet, in effort to keep consistently across the table, the COM pin was referred to as the negative input. This also means that the COM pin can be +/-200mV from the ground plain. This helps in cases where the input source, for example a sensor is far away or on a different board from the ADC. The COM line can be a long connected to the ground of the sensor to keep measurement instead of the ADC ground plane.
In any case, the customer can feel confident in connecting the COM pin to ground
Regards
Cynthia
