"the large print giveth and the small print taketh away" (Quoted from this great description of modern life:
http://www.tomwaits.com/songs/song/322/Step_Right_Up/ ) I'm not trying to be too critical, but look carefully at the datasheet for that part: http://ams.com/eng/content/download/951531/2270299/381482 The "accuracy" can in no way be described as 10 ps. In high resolution mode: * Single shot RMS time resolution: 10 ps typical, 15 ps maximum * Integral non-linearity: 20 ps max * Differential non-linearity: 5 ps typ * Channel to channel isolation: 20 ps typ, 100 ps max * Offset error: 200 ps typ * Offset error drift vs temperature: 1.5 ps typ, 3 ps max / K * FWHM (full width half maximum) histogram: 20-25 ps So if the temperature changes 6 F (3.3 C), the measurement may drift by 10 ps. The single shot absolute uncertainty due to jitter (see the histogram) could easily be +/- 25 ps. There is no mention of long-term drift, since that isn't a typical use of this part. It would be interesting to put one in a simple oven and see how it drifts over a few months. -- Bill Byrom N5BB ----- Original message ----- From: Christopher Hoover <c...@murgatroid.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Subject: [time-nuts] TDC-GPX2 TDC chip Date: Wed, 15 Mar 2017 15:28:20 -0700 http://ams.com/eng/Products/Precision-Time-Measurement/Time-to-Digital-Converters/TDC-GPX2 Claims to have single-shot accuracy of 10 ps. _______________________________________________ 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.