Hi Dan, This is possible with the Broadcom BCM54210SE or BCM54220SE. Ethernet PHY with built in jitter cleaner. External loop filter, 10MHz input is possible, 125MHz output locked to 10MHz is possible but not documented. The Ethernet PHYs will also be locked to the 10MHz input and it has HW 1 step 1588 support I was one of the designers of this part email me off list if you need more info.
Jay On Tuesday, December 31, 2019, 10:15:26 AM CST, Dan Kemppainen <d...@irtelemetrics.com> wrote: Hi All, We've got a project going on where we need a 125MHz clock that should be locked to 10MHz. I'm considering an on board 10MHz oscillator and external 10MHz input to utilize an external standard to lock the 125MHz which would PLL a 125MHz source. The 125MHz becomes a reference for 3.125Ghz, as well as logic running at 125Mhz. (Currently this system is running on small 125MHz TCXO.) Basically we need a reasonably clean 125MHz signal, but locked to 10Mhz for frequency reference. We've identified a few VCXO's that seem to be low noise and are small enough. The 10Mhz is easy enough. However my stumbling block is a simple PLL. What I'm looking for is a simple, small PLL chip. Something with external analog loop filter components to allow easy tweaking would be preferred. In my perfect world, this chip would be a COTS part, with pin strappable divider configuration or similarly simple hardware configuration. An OTP device would work as well, as would one with it's own memory and external programmer. If necessary a small PIC or similar could be used to configure the PLL, but that's one chip which would be nice to avoid. Smaller compact package SMT parts are fine. This is going on a board with lots of SMT components, leadless flat pack devices and BGA's, so smaller is better. If any of you have any suggestions, I'd appreciate it. Happy new year! Dan _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
