Thank you very much for your reply.
The provided information is really helpful to me. As you suggested I have decided to use ADA4941( similar to ADA4940 ). I am using ADA4941 (single to differential converter) as similar to the architecture suggested in the datasheet of AD7982(Page:15, Figure : 26).
The datasheet of ADA4941 doesn't provide the following information.
1. There is no suggestion for selecting the proper external resistors. I need some information about the tolerance and drifts of external resistors to be used. Please suggest some of resistors which suits for ADA4941.
2. The gain error of ADA4941 is mentioned as +/-1% for a gain of 2. Is it the intrinsic gain error associated with ADA4941.