Frequently Asked Question
How do I use a single-ended REF Clock, with a REF Clock input that is differential?
When applying a single-ended Ref Clk the unused REF CLK/, input pin should be coupled to GND or VCC via a coupling capacitor. Additionally a BALUN can be used to convert the clock from single ended to a differential input. Please refer to the device data sheet for specific clocking info. If the input floats, noise on that node could cause erratic clocking and induce additional noise on the clocking signal. It is never a good idea to leave a CMOS input floating.