What is the exact input impedance (LVDS interface) of AD9781? In Datasheet, it is mentioned as 80 to 120 (Rin) ohm. But in the IBIS model, there is no Input impedance shown.
So should we add an external 100ohm resistor at the input? In the SI analuysis, we are seeing that the without this external resistor, the ringing is high.