We are designing a high speed pulse digitizer that needs strictly DC coupled signal path through out (pulses are max +/-500mV and not necessarily DC centered). For ADC the AD9690-500 will do just fine but I have a hard time finding a good enough FDA to go with it. The main problem being the high Vcm that is required for the input buffer of the ADC (2V). All the high speed FDAs are restricted to 5V total supply range and will not work if wasting 2V on Vcm on their output I suppose. Any suggestion?