hello,
please post the schematic. is it an hbridge with current source or any thing else?

Thanks,
Raj.

hello Girish,
i guess it will be tough to define precise gain and BW.

Gain: CMFB gain will decides common mode error, which may impact receiver performance by it's input common mode change. If you have ac coupling at receiver then i guess gain wont impact much. There are few standards which are having tough spec on TX common mode variation, but there will be some min max range.

BW:  For example there if common mode disturbs, then loop should restore back in few bits span otherwise you receiver front end may be effected. This will get you the bandwidth limitation.

Thanks,
Raj.