I recently built the reference design included with the AD8295 datasheet, which uses the AD8295 to differentially drive an AD7690 ADC chip. This is a very compact implementation but I can't seem to get it to work correctly.
That said, I notice that the evaluation board for the AD8295, EVAL-CN0225, implements a different approach using an AD8275 to generate the differential signal driving an AD7687. I'm not able to find any confirming implementations for the AD8295/AD7690 combination but I haven't seen any web references suggesting that the design has any problem or needs additional components.
I have attached my schematic of the amplifier section. I have four of these channels in a compact area that is space constrained.
Can anyone comment on this in general? I can be more specific later.
Perhaps a few more clues would help us. What did you expect the circuit to do and what are you observing it to be doing that is "not working."