Clock behavior of CY26049 when reference fails

Question: What happens when the reference of CY26049 fails?

 

Answer:

The clock output from the CY26049 will be constant if the reference fails. Once your reference goes away, the output frequency will stay constant with the last known ppm offset, but the phase will start to drift because there is no reference to which to lock. When the reference comes back, the phase will be readjusted to match the new reference.