In SOM2, clock input to AD9361 is selected between 40MH crystal output or external clock signal using ADG772 mux. It is mentioned in the schematic that, the external clock signal should be 1.3V pk-pk max. but the 40MHz crystal o/p is 1.8V max. Whether i can feed 1.8V pk-pk CMOS signal as external clock signal from a TCXO.
Please refer to the below thread