Depending on your needs there are many off-the-shelf programmable frequency divider IC's.
Most of the modern ones are not programmed by strapping pins but by serial connection to a microcontroller so this may not be your cup of tea. If so, look at the math and note that 81 = 9*9 or 3*3*3*3. Two divide-by-nines in series is very straightforward with something as old fashioned as a couple 7490's with some AND gates. And four divide-by-threes in series is done with bare flip flops. You can even google to find divide-by-three with a square wave output if that's what you need. Tim N3QE On Thu, Jun 18, 2020 at 11:42 AM Gilles Clement <clemg...@gmail.com> wrote: > Hi > I need to divide the output of an OCXO by a factor D=81 for testing > purposes. So with minimum added phase noise. > PICDIV-like approches would not work (D needs to be divisible by 8 or at > least be even) > I went through the archives and it seems that an Injection Locked > Frequency Divider with resynchronization flip-flop could be a simple and > acceptable solution. > As described in the following Wenzel paper: Unusual Frequency > Dividerswww.wenzel.com › uploads › dividers < > https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwik49qGpIvqAhURahQKHTBVClAQFjABegQIARAB&url=http%3A%2F%2Fwww.wenzel.com%2Fwp-content%2Fuploads%2Fdividers.pdf&usg=AOvVaw2m-9lURROiSbG9XykiDNDU > > > Does this make sense? > Gilles. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.