Hi Without doing a bunch of actual *work* I’m not sure what is inside the guts of the board. Being lazy I’ll just guess ….
There appears to be a 10 MHz time base input and a pair of measurement inputs. In a lot us will be comparing to a “house standard”. That standard has a pps output that is related directly to the 10 MHz reference. If I can uniquely identify one edge (out of 10 million edges) as the right edge, I can use the 10 MHz as my pps reference. Put another way, I don’t really need to measure a pps input from the house standard if I’m already locked up in phase to the 10 MHz. All I need to do is to tag an edge / reset a counter. The advantage of this is that I may not need another fancy TDC chip to set up the reference. I can use *both* inputs for DUT’s rather than using one as a reference. Part of the reason I’m guessing this would work is the claim that boards can be stacked for multiple input setups …. Bob > On Nov 27, 2016, at 7:36 AM, timeok <tim...@timeok.it> wrote: > > > 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-boun...@febo.com > To "Discussion of precise time and frequency measurement" time-nuts@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 > _______________________________________________ > 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.