Hi The simple answer is that pumping the sine wave into a biased logic gate works down to at least the 2x10^-13 (at 1 second tau) level.
Why spend more than 10 cents when you don’t have to ? Bob > On May 18, 2015, at 6:19 AM, Bryan _ <bpl...@outlook.com> wrote: > > Hi Bob: > > i assume when you are referring to the comparator you are referencing the > ADCMP600 or MAX999 that is used to clock shape the input for the logic > dividers etc and the 74AC541 bus drivers. > > Could one modify the circuit to use a low noise LTC6957 to clock shape and > then divide down using the existing circuitry. I would assume this would > offer a greater improvement in phase noise? > > Cheers > > > -=Bryan=- > >> From: kb...@n1k.org >> Date: Fri, 8 May 2015 17:19:59 -0400 >> To: time-nuts@febo.com >> Subject: Re: [time-nuts] Divider circuit for Rubidium Standard >> >> Hi >> >> I guess the simple answer is “when you measure them that’s the result”. >> >> The slightly more complex answer is “fast silicon CMOS is indeed good, other >> types may require further analysis”. In general the faster stuff is better >> than >> the slower CMOS. >> >> Deeper into it you get to the fact that the gate is optimized for one input >> swing range, >> speed and consistent (short) delay. The amount of time that anything in a >> CMOS gate spends >> in-between “on” and “off” if very short. If you look at the time it’s hooked >> to a rail as noiseless (= >> quiet supplies), then the time noise can get into the output is quite short. >> Short time = little noise. >> >> You could go further with fancy tools. >> >> Bob >> >> >>> On May 7, 2015, at 11:09 AM, Attila Kinali <att...@kinali.ch> wrote: >>> >>> On Wed, 06 May 2015 18:09:03 -0700 >>> "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: >>> >>>>> A standard input on a frequency counter is not a very demanding thing in >>>>> the hierarchy of >>>>> TimeNut signals. You can drive any of them with some pretty simple logic >>>>> gate based >>>>> circuits. No need to spend a lot of money. >>>> >>>> Logic gate, yes. Comparator, no. >>> >>> This reminds me a lot of a similar discussion a couple of weeks ago. >>> (where the issue boiled down to noise bandwidth) >>> >>> What is the problem with a comparator vs a logic gate? >>> What makes the logic gate supperior? >>> >>> Attila Kinali >>> >>> -- >>> It is upon moral qualities that a society is ultimately founded. All >>> the prosperity and technological sophistication in the world is of no >>> use without that foundation. >>> -- Miss Matheson, The Diamond Age, Neil Stephenson >>> _______________________________________________ >>> 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. > > _______________________________________________ > 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.
