How do I feed a single-ended signal into a differential input?

It is possible to drive a differential input with a single-ended clock signal. This is done by AC coupling the single-ended signal into one side of the differential input. The other side of the differential input is connected via a capacitor to a quiet ground. The inputs of the AD951x series of parts are self-biased, so no common mode voltage must be set. The performance of the input is not reduced by coming in single-ended rather than differential.

Alternatively, a single-ended clock signal can be converted to differential by using a balun or transformer. The differential signal should be AC coupled into the inputs because they are internally biased.