I'm using the AD9578 evaluation board, and I'm experiencing what I hope is two related problems. Once I enable the outputs, the PLLs do not lock for several minutes, if at all. I'm unclear what does cause them to finally lock.
Even after they do lock, I'm measuring 8 ps of RMS jitter and 30ps of peak to peak jitter on a nominally 100MHz output. I do not notice any measureable change in jitter between locked and unlocked. I need to get that jitter down to a picosecond or less.
Is this level of jitter expected? Do I have a faulty board?
Can you recommend a lower jitter solution? I need two clock outputs with 1ppb resolution and >ps rms jitter. My current plan is to keep the AD9578 and add a pair of jitter attenuators - any favorites for this application?
The two clocks will typically be within a few ppm of each other, so I'm a little worried on spurs. Jitter situation happens without turning on the other generator though.