Hi, Comparing a reference signal at 162kHz with local 10MHz ocxo. Expected Adev 10E-11 at 10sec. 162kHz / 81 = 2kHz = 10MHz / 5000 GC
> Le 21 juin 2020 à 05:49, Bob kb8tq <[email protected]> a écrit : > > Hi > > *Any* divide approach followed by a flip flop clocked by the input clock will > meet > that same basic requirement. While it *sounds* like it would improve things, > it > very much depends on the details. > > What are you trying to do? What is the input frequency? What is the phase > noise > requirement? > > Bob > >> On Jun 20, 2020, at 2:22 PM, Gilles Clement <[email protected]> wrote: >> >> Hi Robert, >> You are right, its the lambda divider that was discussed. Need to better >> understand this approach.... >> 74HC40103 could also do the 81 Pi-divide easily, but I tend to prefer the >> PICDIV concept where the controller is clocked by the signal to divide (So >> limited or no noise is added). AVR family could do it, as most of the >> instructions take only one clock. >> Gilles. >> >> >>>> Le 20 juin 2020 à 19:48, Robert LaJeunesse <[email protected]> a écrit : >>> >>> Gilles, if I read the Calosso-Rubiola paper correctly a Pi divider is >>> pretty much your standard square-wave producing digital divider, such as a >>> 74163 (for even divides). There's odd-value (3,5,7) Pi dividers shown at >>> https://www.theremin.us/Circuit_Library/symmetrical_digital_dividers.html. >>> What the Calosso-Rubiola paper promotes is the Lambda divider, which is >>> depicted in figure 2 of the paper. >>> >>> Bob L. >>> >>>> Sent: Friday, June 19, 2020 at 10:27 AM >>>> From: "Gilles Clement" <[email protected]> >>>> To: "Poul-Henning Kamp" <[email protected]> >>>> Cc: "Discussion of precise time and frequency measurement" >>>> <[email protected]> >>>> Subject: Re: [time-nuts] Frequency division by 81 >>>> >>>> Hi, >>>> Could you point me to a practical design example of a Pi divider ? >>>> >>>> >>>> Envoyé de mon iPad >>>> >>>>>> Le 19 juin 2020 à 08:56, Poul-Henning Kamp <[email protected]> a écrit >>>>>> : >>>>> >>>>> -------- >>>>> >>>>>> I need to divide the output of an OCXO by a factor D=81 for testing >>>>>> purposes. So with minimum added phase noise. >>>>> >>>>> Two stages of divide by 9 PI-dividers ? >>>>> >>>>> http://rubiola.org/pdf-articles/conference/2013-ifcs-Frequency-dividers.pdf >>>>> >>>>> -- >>>>> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >>>>> [email protected] | TCP/IP since RFC 956 >>>>> FreeBSD committer | BSD since 4.3-tahoe >>>>> Never attribute to malice what can adequately be explained by >>>>> incompetence. >>>> >>>> _______________________________________________ >>>> 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. >> >> _______________________________________________ >> 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. _______________________________________________ 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.
