than 10mS when the input level is below 200mV.
But it seems very difficult for AD736(or for other RMS-to-DC converter from
ADI) to meet such a requirement?
The settling time of the AD736 is a well known issue and it a result of the
design of this device. It can be improved by using the smallest possible value
of averaging capacitor and using the external filter to suppress ripple.
The problem has been fixed in the AD8436. The settling time is dependent only
on the averaging capacitor, not the input level.