with 3.3 volt?
The PGA is implemented by changing the sampling of the input signal, this is a
common PGA structure for most of our sigma delta converters, therefore the
response time of the PGA is not an issue. Changing from 0 to 38db, is
equivalent to a step change or a channel change at the input. The delay to o/p
can be obtained by looking at the group delay of the filter for the various
sampling rates on page 2 of the datasheet.