[time-nuts] New Timestamping / Time Interval Counter: the TICC

timeok timeok at timeok.it
Sun Nov 27 12:36:05 UTC 2016


   Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and the 10Mhz clock as single reference.
Luciano
www.timeok.it


   From "time-nuts" time-nuts-bounces at febo.com
   To "Discussion of precise time and frequency measurement" time-nuts at febo.com
   Cc
   Date Wed, 23 Nov 2016 10:48:57 -0500
   Subject [time-nuts] New Timestamping / Time Interval Counter: the TICC
   Counters with resolution below 1 nanosecond are difficult. They require
   either outrageous clock speeds, or interpolators that are typically a
   bunch of analog components mixed with black magic and stirred by
   frequent calibration. The very best single-shot resolution that's been
   commercially available is 22 picoseconds in the HP 5370A/B, with jitter
   somewhat more than that. My 5370B has an one-second noise ADEV of about
   4x10e-11.

   With the help of some very talented friends, I've been working on a new
   counter called the "TICC" with <60ps resolution and similar jitter,
   based the Texas Instruments TDC7200 time-to-data-converter chip. The
   noise ADEV is about 7x10e-11, not much worse than the 5370,
   but here's the trick: the TICC is an Arduino shield (mounting a Mega
   2560 controller) that weighs a couple of ounces, requires *no*
   calibration, and is powered from a USB cable!

   The TICC is implemented as a two-channel timestamping counter. That
   means it can measure or two low-frequency (e.g., pulse-per-second)
   inputs against an external 10 MHz reference, or it can do a traditional
   time interval measurement of input against the other. It can also
   measure period, ratio, or any other function of two-channel timestamp
   data. (And by the way -- multiple TICCs can be connected to yield 4, 6,
   8, or more synchronized channels, though we haven't tested this
   capability yet.)

   I've attached a picture of the TICC prototype as well as an ADEV plot of
   a 17+ day run of multiple measurements taken by two TICCs, and also
   showing the TICC noise floor. The good news behind that plot is that
   there are more than 6 million data points behind these results, and
   there was not a single glitch or significant outlier among them.

   There's more information available at http://febo.com/pages/TICC

   The software is open source (BSD license) and is available at
   https://github.com/TAPR/TICC -- the current version seems be reliable
   but there are still features to add and a *lot* of cleanup to do; it's
   currently ugly and very much a work in process.

   As always, I'll be making the TICC available through TAPR. We're still
   finalizing details, but we expect the price to be less than $200 for a
   turn-key system: TICC mounted an Arduino with software loaded and
   tested for basic functionality. We hope to ship the TICC by February.

   I'll post a note in a week or two with final price and ordering
   information. As a heads up, we will probably offer a small discount for
   pre-orders. TAPR is a shoestring non-profit group and the up-front cost
   to manufacture this unit will frankly be a challenge for us. Getting
   pre-orders will help our cash flow significantly, so we ask you to keep
   that in mind.

   John



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