SG8002 is definitely a distributor programmable unit. It is a digital synthesizer in a can with no effort towards clean output.
PLL? They would not bother to put a cleanup PLL in the can for the intended microprocessor application. Tim N3QE On 7/21/13, Didier Juges <shali...@gmail.com> wrote: > I am familiar with the Epson Seiko SG8002 series and nowhere does it say > they are programmable. They are not user programmable for sure, only the > distributor has the tools to do it. The data sheet does not have any > information that would be a hint that they are PLL's. > > Http://WWW.KO4BB.com/Timing/MicroprocessorCrystals.php > > Didier > > Hal Murray <hmur...@megapathdsl.net> wrote: >> >>li...@rtty.us said: >>> A number of them are sigma delta PLL's and have some really nasty >>jitter and >>> spur issues. Anything that shows up listed as "user programmable" - >>watch >>> out. >> >>But "user programmable" won't find all the nasty ones. >> >>I haven't been looking recently. There used to be some that were field >> >>programable. The idea was that the distributor would do it so you >>didn't >>have to wait for the factory to grind the crystal to order if you >>wanted an >>oddball frequency. They didn't mention the PLL in the data sheet. You >>had >>to read between the lines. >> >>I assume the distributor stocked a handful of basic frequencies and >>there was >>a PC that told them which one to use and did the programming if you >>told it >>what frequency you wanted. >> >>It looks like a fun math problem. How many frequencies do you need to >>stock >>in order to cover a given frequency range with a given PLL chip? The >>result >>doesn't have to be a direct hit. You can include some fudge as part of >>the >>overall accuracy spec. (If you claim 100 PPM, but cut the crystal >>within 50 >>PPM, then you have 50 PPM left for the PLL.) >> >> >> >>-- >>These are my opinions. I hate spam. >> >> >> >>_______________________________________________ >>time-nuts mailing list -- time-nuts@febo.com >>To unsubscribe, go to >>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>and follow the instructions there. > > -- > Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other > things. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.