I'm looking for a ~1GHz+ differential amp with high input impedance to sense a current. The AD4960 seems ideal with the decoupled feedback resistors and 10kohms differential input resistance. I'm not clear however from the data sheet on how large the impedance between input common mode and ground is? Is it just the 5kohms single-ended input impedance (I hope not)?
I wanted to test it myself, but when getting the 4960 and the EVAL-FDA-1CPZ-16 evaluation board for fully diff amps with LFCSP-16 package I noticed that the pinout is not compatible. It would be great you either have that parameter in the datasheet or could provide it.
Also, I'm happy to consider other differential amps with same or better bandwidth and high input impedance. I don't care about gain too much as I can easily boost the signal with the low-impedance differential output after the fist stage.