I am currently developing a board based on the AD9219, and am seeking to design a clock input. Could the clock be provided by a low jitter analogue sine wave? or must be the clock be digital?
We often use a sine source to clock our high-speed ADCs. You will see a description of that recommendation on page 37, and on page 41 there is a schematic of how we use a transformer and some Schottky diodes to transform to a differential signal and clip the sine source. This preserves the high slew rate portion of the sine input without overdriving the clock input, thereby providing a low jitter clock to the ADC.
Good luck with your design,