Hi The “simple / easy / quick” approach is a pps generated by source with a small frequency offset. If your objective is 5 ps, both your reference and your offset source will need to do better than that. While that sounds like it’s specific to this technique, it’s actually a more general constraint.
Just how hard this is depends a bit on your definition of jitter. Since you are looking at 1 second, ADEV with a tau = 1 second *might* be a reasonable measure. If it is, then you need two sources that are well below 5x10^-12 at one second. That eliminates most signal generators and many atomic standards. This gets you to using things like Masers or some pretty good OCXO’s. Tuning a Maser for a low offset is doable. Tuning an OCXO … maybe not so much. Bob > On Nov 29, 2017, at 4:24 PM, Leo Bodnar <l...@leobodnar.com> wrote: > > I am looking for an established and widely accepted procedure for verifying > performance of high resolution time counters. > > I have designed a time stamping counter for qualifying 1PPS signal > performance against external reference (e.g. 10MHz master clock.) > > Simple design verification check I am doing at the moment is gating random > selection of master clock edges back into device's signal input and letting > the device measure this test signal offset against its reference clock - > which, for ideal design, should result in zero offset (modulo 100ns.) My > results are roughly in line with what I expect to see > http://leobodnar.com/balloons/NTP/time-sampler-test1.png > > Now, what would be recognised procedure for sweeping external input pulse > delay over few hundred ns in a controlled, measurable and repeatable way? > > I can see few naïve approaches: > 1) Using selectively gated (or divided) reference clock followed by > adjustable delay line. E.g. something like mechanically adjusted delay lines > used in HP test sets. Or, perhaps, calibrated rigid coax sections? > 2) Slightly offset another master clock (e.g. second Rb oscillator) gated in > a similar way but without delay line, followed by statistical data analysis > 3) Trusted pulse generator with high resolution delay adjustment fed from the > same master clock as the counter > > I am looking for something with ~10ps accuracy, 100ns+ range, and reasonably > low jitter (~5ps or better.) > It is possible that the range needs to be split up (e.g. fixed rigid coax > delay line followed by a mechanically adjust section.) > > This is a low budget fun project so something simple and common sense is > preferred to "price on application" NIST traceable equipment. > > Thanks! > Leo > _______________________________________________ > 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.