@Chaitanya,
Thanks for the email, I am the applications engineer for rms-dc converters.
This looks like a recent application question from another customer. If I may suggest an alternative device, I developed a single-ended solution with provision for driving a follow-on device with a dissimilar common-mode voltage. You can ac couple the response from the 22051, then re-combine the rms result following conversion. I just released an application note that shows how to do this trick. The application is designed around our recently released AD8436 rms-dc converter. Attached are PDFs of the data AD8436 and AN1341.
Good luck!