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

John Ackermann N8UR jra at febo.com
Wed Nov 23 10:48:57 EST 2016

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 

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 on the Texas Instruments TDC7200 time-to-data-converter chip.  The 
one-second noise ADEV is about 7x10e-11, not much worse than the 5370, 
but here's the trick:  the TICC is an Arduino shield (mounting on a Mega 
2560 controller) that weighs only 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 one 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 one 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 on 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.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: TICC_rev_c_photo_small.jpg
Type: image/jpeg
Size: 84763 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20161123/98f898a4/attachment-0001.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ticc_rev_c-perf_test_adev.png
Type: image/png
Size: 100537 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20161123/98f898a4/attachment-0001.png>

More information about the time-nuts mailing list