Don't forget the "regenerative" frequency divider concept, either. At some point you'll need to do some division, and these things seem to have a rep for better phase noise performance than logic-based dividers.
Dana On Tue, Dec 31, 2019 at 10:15 AM Dan Kemppainen <[email protected]> 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 -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
