Can I use AD9558 or AD9558 with gapped clock for asynchronous demapping SDH from OTN?
Yes. Absolutely. We've done many tests with gapped clocks.
However, depending on how big the gaps are, you may see the following behavior:
1. The lock detect may indicate loss of lock. However, the lock detector is extremely flexible, so we may only need to experiment with the best settings.
2. You may have to use manual reference validation. If you do, automatic reference switching will not work.
One nice thing about the AD9557/58/59 is that it's possible to set the loop BW as low as 0.1 Hz, which is extremely effective for filtering gapped clocks.