I use AD9517-1 to generate DAC reference clock, REF1 and REF2 are 10MHz, AC-Coupled, LVCMOS, both about 100Hz deviation, the clock can be locked, VCO 2400MHz. If I use any of the references, the clock output spectrum is very good, but if I enter two clocks at the same time and prefer to use REF1, the clock output near the spectrum(in 10kHz range) will appear some spurs, the range of about -50dBc. I analyzed REF2 for REF1 interference, but the actual working conditions REF1 and REF2 must exist at the same time, in this case the spurs can be eliminated? Or what other ways to reduce these spurs?
Looking forward to reply, thank you very much!