Hello Tom,
I dug through our data, and we have very little data with AVDD=3.3V. Noise is measured with AVDD=3V, and can be found in tables 7-3 and 7-4 of the ADS1232 datasheet. Also, we do specify PSRR, which looks like an offset voltage change relative to the AVDD voltage. However, I was not able to find any gain data verses supply voltage, but was able to confirm linearity (INL) holds for a 3.3V supply voltage. These errors are typically due to internal resistor tolerances, and will not change significantly over operating voltage.
In general, we recommend some type of system calibration for gain, which is common for weigh scale applications. In this case, the gain errors are reduced to the level of measurement noise, and the initial gain error is less of a concern in these use cases.
If you need more comprehensive specifications for gain at your specific supply voltage, I recommend looking at either the ADS1220 or ADS124S08 devices. The ADS1220 is specified with AVDD=3.3V, and the ADS124S08 is fully specified over the entire AVDD voltage operating range of 2.7V up to 5.25V.
Regards,
Keith
