Hi If you are talking about a conventional PLL, the days of pin programable single chip devices are long gone. Indeed they didn’t last long “back in the day”. The most common answer is to hook up a cheap micro to shoot the registers. You could also do it with an FPGA. A lot depends on what is already in the system.
With logic, GHz, and a PLL involved, isolation to keep crud down will be part of the answer ….. Bob > On Dec 31, 2019, at 11:01 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.
