AD9549 no PLL lock


I am using an AD9549 on our own board:

  • 10 MHz Input on REFA
  • 10 MHZ (XO) Input for SysCLK
  • 1 GHz SysCLK
  • 10 MHZ Output

I start with the single tone mode (which works fine) and change to closed loop after a valid signal is detected on REFA.

The holdover and recovery works also fine, but I get never a phase lock and I also see on the oscilloscop that the output signal is not locked to the reference signal.

Is there a way to debug this problem?

Best Regards,