The AD9528 data sheet directs as follows in Table 4. "Can accommodate single ended input via ac grounding of unused input; instantaneous voltage on either pin must not exceed 1.8V". The AD9528 EVAL BOARD schematic appears setup to drive this pin directly from a CHVD-950 VCXO output which has 3.3V drive. Seems like a conflict! The data sheet also presents a substantial amount of characterization data using the CHVD-950 VCXO. Can the AD9528 VCXO pin be safely driven above 1.8V in single ended mode? ....and.... How should this VCXO be connected to the AD9528?