I want to set up a fractional-N PLL with a deterministic phase relationship between RF out and REFin. Specifically, REFin will be 49.92 MHz and RFout will be 38.4 MHz. If REFin drops out momentarily, RFout needs to be lined up with REFin when REFin resumes. REFin may change over the life of the project by up to +/- 40 kHz.
I tried this out with a competitor's product who claimed a deterministic relationship but we found that only worked when integer-N division was being used. I believe you refer to it as "Phase Resync"? I know some of your PLLs have this feature but before I start searching through them I need to know if your phase resync applies to fractional-N as well. I'm perfectly ok with using an external VCO if necessary.