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.
