I want to use the AD8429 with the inputs AC coupled, with 100k resistors to ground at each amp input.
Since the offset current can be 100nA, a 10mV DC differential can exist. To get the low noise, I need Gain of 1000, Rg= 6 ohms,
which would mean a 10V signal at the output, if the offset is not corrected.
If I use the Ref pin, I need to connect a +/-10V signal to it. I also lose significant dynamic range. Also, the source resistance must be VERY low to avoid decreasing the astronomical CMRR of the AD8429.
The only alternative I can see is to connect a bias network to one of the input resistors, and apply a voltage ~ 10mV
to the 100kohm resistor.