By precision I mean that my peak detector shall give DC output corresponding to 1mV p-p to 10V AC input signal, with step size of 1mV. The ripple shall be negligible.. I hope it is clear.
Your concept of 1mV pp to 10VAC peak detection means chopped fn of 10e4.
Accurate determination to 1mV ripple means another 10e-3 .
As such your total chopper frequency for peak and hold needs to be t=10e-7.
Where will you get 10Mhz clock?
Kindly see for getting more realistic OR consider breakup in two overlapping ranges .