ADS5463: The DRY pin output of the ADC is at 250M, and also at 750M, and the harmonics at 750M are quite comparable in size to those at 250M.

The clock signal I provide to the ADC is 500M, passed from the LMK, AC coupled, not a standard sine wave, 0.8VP-P. Then I measured the ADC's DRY pin with an oscilloscope and found both a 250MHz and a 750MHz signal, both having similar peak values. Is this normal, due to the need to transmit data on both the rising and falling edges?