Hi Gonzalo-
We use a Marki Microwave balun, BAL0006GSMG on our evaluation boards for AD9625.
Some alternate choices are:
MiniCircuits TCM1-83X+
MiniCircuits TCM1-63AX+
MiniCircuits TCM1-43X+
Anaren B0322J5050A00
We recommend two front-end network designs based upon the bandwidth needed to the ADC:
<2Ghz BW (Best SNR/SFDR performance):
>2Ghz BW (Highest Bandwidth):
Thanks,
Ian Beavers