[time-nuts] 50 ohm driver

Sat Mar 7 21:40:55 UTC 2015

The MOSFET drivers are limited in the max frequency they can operate at without burning. At 1 Hz it is of course not a problem but at 10MHz it most definitely would be.

Since Martin did not originally say at what frequency he wanted to operate, it was most relevant.

MOSFET drivers can deliver a few nS edges while driving significant capacitance at several hundred kHz. They can be very useful for "low" frequency clock drivers.

Didier KO4BB

On March 7, 2015 10:10:45 AM CST, Graham / KE9H <ke9h.graham at gmail.com> wrote:
>The question is not the frequency, but the edge rate.  For a 1 PPS
>signal,
>how fast a rise time do you need?  Do you want to know the time of the
>edge to 1/100 second? one microsecond? one nano-second? A few
>pico-seconds?
>
>If you want to know the time of the edge to one nano-second, then you
>need a driver that can push sine-waves at over a few GHz. Not 10 MHz.
>
>--- Graham / KE9H
>
>==
>
>On Sat, Mar 7, 2015 at 7:58 AM, Didier Juges <shalimr9 at gmail.com>
>wrote:
>
>> Martyn, if you only need 1Hz, I recommend you use a MOSFET driver
>like the
>> MIC4420 series or the UCC27531, powered from 10V with a 50 ohm output
>> resistance. These parts have several A current capability, 18V or
>more max
>> VCC and are designed to drive capacitive loads (large MOSFET gate
>> capacitance). It would not work at 10MHz (because of propagation
>delay and
>> self heating), but at lower frequencies, they work very well.
>> The UCC27531 has lower propagation time and comes in an SOT-23
>package, the
>> others are available in DIP-8 and SO-8.
>>
>> Didier KO4BB
>>
>> On Thu, Mar 5, 2015 at 3:59 PM, Martyn Smith <martyn at ptsyst.com>
>wrote:
>>
>> > Hello,
>> > Thanks for all the feedback.
>> > I should explain.  I have an existing product that uses the 74AC14.
>> > I have a customer who needs 5V into 50 ohm and can’t wait for the
>> > competitive product that does this, or for me to re-design my unit.
>> > So I have been looking for a quick fix.
>> > I got excited when I found the SN74AS1004AD which has the exact
>same
>> > function and pin out but delivers 48 mA per channel.
>> > While one output did give me 0-3.0 V into 50 ohm, combining them,
>as we
>> do
>> > for the 74AC, actually produced worse results.
>> > Maybe the output driver is different.
>> > Anyway I’ve managed to get 0-4.8V by jacking up the supply voltage
>to 5.7
>> > V for the 74AC14 and making the three 47 ohm resistors 0 ohm.
>> > Risetime < 4 ns.
>> > Basically to ideas that TimeNuts gave me.
>> > I’m just worried the IC may die after a few months.  But since the
>> > customer will only use it at 1 Hz and hopefully 50:50 duty, or
>less, I
>> hope
>> > to get away with it.
>> > Of course if he removes the input and the outputs are on high, then
>that
>> > may be a problem.
>> > BTW, the reason he wants this high voltage is because he is driving
>a
>> very
>> > long cable from the distribution  amp to the actual receiver.
>> > Anyway I have an IC on test for a week to make sure it lasts.
>> > Regards
>> > Martyn
>> >
>> >
>> > Today's Topics:
>> >
>> >    1. Re: 50 ohm Driver (Bob Albert)
>> >    2. Re: 50 ohm Driver (Graham / KE9H)
>> >    3. Re: 50 ohm Driver (Tom Van Baak)
>> >    4. Re: 50 ohm Driver (Hal Murray)
>> >    5. Re: 50 ohm Driver (Dan Kemppainen)
>> >    6. Re: Trimble Thunderbolt NMEA ? (Didier Juges)
>> >    7. Re: 50 ohm Driver (Bob Camp)
>> >    8. Re: 50 ohm Driver (Charles Steinmetz)
>> >    9. Re: new tdc from Texas (Angus)
>> >   10. Re: new tdc from Texas (Attila Kinali)
>> >
>> >
>> >
>----------------------------------------------------------------------
>> >
>> > Message: 1
>> > Date: Wed, 4 Mar 2015 16:49:11 +0000 (UTC)
>> > From: Bob Albert <bob91343 at yahoo.com>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID:
>> > <1276775018.2671439.1425487751520.JavaMail.yahoo at mail.yahoo.com>
>> > Content-Type: text/plain; charset=UTF-8
>> >
>> > 5V into 50 Ohms means 100 mA.  Perhaps you need a medium power
>transistor
>> > amplifier or opamp.
>> > Bob
>> >
>> >
>> >      On Wednesday, March 4, 2015 6:09 AM, Martyn Smith <
>> martyn at ptsyst.com>
>> > wrote:
>> >
>> >
>> > Hello,
>> >
>> > A quick question.
>> >
>> > My output driver for a simple amplifier.
>> >
>> > I use three gates (in parallel with resistors) from a 74AC14 to
>give me
>> > about 0-3.2V into 50 ohm.
>> >
>> > I want to have a driver that gives me a full 0-5V (at least 0-4.5V)
>swing
>> > into 50 ohms.
>> >
>> > Can anyone recommend an IC that can delivery this.
>> >
>> > But it needs to have similar jitter performance to the 74AC14.
>> >
>> > I use it up to 10 MHz.
>> >
>> > Best Regards
>> >
>> > Martyn
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-nuts at febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>> >
>> >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 2
>> > Date: Wed, 4 Mar 2015 12:16:02 -0600
>> > From: "Graham / KE9H" <ke9h.graham at gmail.com>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID:
>> >
><CAPyJ-YXrLKw6Y-PogLqWjSS+MEHm6iFc+etyB-mccZkhJPWOQg at mail.gmail.com>
>> > Content-Type: text/plain; charset=UTF-8
>> >
>> > Building on top of John's comments, if you are using a logic gate,
>look
>> at
>> > the
>> > maximum output (pull up) current per pin, set the series resistor
>so that
>> > this
>> > current is not exceeded into a short, then also see if there is a
>maximum
>> > total
>> > current draw for all gates combined, or some power input pin, and
>do not
>> > exceed
>> > that.
>> >
>> > You can also look at switching the termination resistor from a
>simple 50
>> > Ohm
>> > resistor to ground, to a "Thevenin" load, which is 100 Ohms from +V
>to
>> the
>> > load point,
>> > and another 100 Ohm resistor from the load point to ground. This
>way you
>> > still have a 50 Ohm termination, but only draw one half the DC
>current.
>> > In the event of no input, the receiver voltage will go to half
>scale.
>> Make
>> > sure your system will not misbehave when this happens.
>> >
>> > Alternate driver is to use a video line driver with sufficient
>bandwidth.
>> >
>> > --- Graham / KE9H
>> >
>> > ==
>> >
>> > On Wed, Mar 4, 2015 at 7:54 AM, John Ackermann N8UR <jra at febo.com>
>> wrote:
>> >
>> > > One comment on the parallel AC gate approach.  It may not be
>directly
>> > > applicable to Martyn's issue, but there is a common confusion
>about the
>> > > value of the summing resistors.
>> > >
>> > > Per Tom Clark, who came up with the idea, they are *not* intended
>to
>> > > provide a near-end line termination to 50 ohms, but are simply
>there to
>> > > protect the paralleled devices if the gates have slightly
>different
>> > delays
>> > > (in which case one gate could end up sinking the other two).
>> > >
>> > > So, the commonly used 47 ohm value isn't magic.  You can use a
>lower
>> > > value, and thus get more voltage at the far end.  I haven't
>> experimented
>> > to
>> > > see how far you can take that idea before destroying gates.
>> > >
>> > > John
>> > > ----
>> > >
>> > > On 3/4/2015 5:26 AM, Martyn Smith wrote:
>> > >
>> > >> Hello,
>> > >>
>> > >> A quick question.
>> > >>
>> > >> My output driver for a simple amplifier.
>> > >>
>> > >> I use three gates (in parallel with resistors) from a 74AC14 to
>give
>> me
>> > >> about 0-3.2V into 50 ohm.
>> > >>
>> > >> I want to have a driver that gives me a full 0-5V (at least
>0-4.5V)
>> > swing
>> > >> into 50 ohms.
>> > >>
>> > >> Can anyone recommend an IC that can delivery this.
>> > >>
>> > >> But it needs to have similar jitter performance to the 74AC14.
>> > >>
>> > >> I use it up to 10 MHz.
>> > >>
>> > >> Best Regards
>> > >>
>> > >> Martyn
>> > >>
>> > >> _______________________________________________
>> > >> time-nuts mailing list -- time-nuts at 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 at febo.com
>> > > To unsubscribe, go to https://www.febo.com/cgi-bin/
>> > > mailman/listinfo/time-nuts
>> > > and follow the instructions there.
>> > >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 3
>> > Date: Wed, 4 Mar 2015 10:20:45 -0800
>> > From: "Tom Van Baak" <tvb at LeapSecond.com>
>> > To: "Discussion of precise time and frequency measurement"
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID: <231A4CB7D0CB45CAAF6A3015A4900374 at pc52>
>> > Content-Type: text/plain; charset="utf-8"
>> >
>> > Martyn -- the 74AC spec allows Vcc to go up to 6.0 VDC (absolute
>max is
>> > 7.0 VDC) so that might help you meet your 4.5 VDC goal, especially
>if
>> this
>> > is for play and not a product. Pick the resistors and use more than
>3
>> gates
>> > if necessary. Note the peak current spec is 50 mA per gate. Not
>sure what
>> > the combined gate current limit is; there is a package thermal
>limit. You
>> > also have to decide if you want some level of short-circuit
>protection or
>> > if you can always assume 50R termination.
>> >
>> > John -- have you tried long duration output shorts on the TADD-2? I
>> > figured that was also a reason for each gate having its own
>resistor.
>> >
>> > /tvb
>> >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 4
>> > Date: Wed, 04 Mar 2015 12:03:16 -0800
>> > From: Hal Murray <hmurray at megapathdsl.net>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Cc: hmurray at megapathdsl.net
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID:
>> > <20150304200316.6AFBC406057 at ip-64-139-1-69.sjc.megapath.net>
>> > Content-Type: text/plain; charset=us-ascii
>> >
>> >
>> > jra at febo.com said:
>> > > Per Tom Clark, who came up with the idea, they are *not* intended
>to
>> > > provide a near-end line termination to 50 ohms, but are simply
>there to
>> > > protect the paralleled devices if the gates have slightly
>different
>> > delays
>> > > (in which case one gate could end up sinking the other two).
>> >
>> > Is that a real problem?  How far off can the prop delay be for 2
>gates on
>> > the
>> > same chip?
>> >
>> > I seem to remember reading something saying it was OK to just wire
>them
>> up
>> > in
>> > parallel.  It could have been an app note, or it could have been a
>rumor
>> on
>> > usenet.
>> >
>> > --
>> > These are my opinions.  I hate spam.
>> >
>> >
>> >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 5
>> > Date: Wed, 04 Mar 2015 15:57:56 -0500
>> > From: Dan Kemppainen <dan at irtelemetrics.com>
>> > To: time-nuts at febo.com
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID: <54F771D4.4010500 at irtelemetrics.com>
>> > Content-Type: text/plain; charset=utf-8; format=flowed
>> >
>> > Hi,
>> >
>> > Correct me if I'm wrong but being that AC series gates are MOS
>devices,
>> > isn't there inherent current limiting in the MOS junction itself? I
>> > would think that for the few nanoseconds of skew across gates the
>tens
>> > of ohms of junction resistance would make 'shoot through'
>negligible in
>> > terms of heating and gate damage.
>> >
>> > Of course, a TTL device would be a completely different story and I
>> > would fully expect summing or balancing resistor would be needed
>there.
>> >
>> > Does anyone have further input regarding paralleling MOS logic
>devices?
>> >
>> > Dan
>> >
>> >
>> >
>> > > One comment on the parallel AC gate approach.  It may not be
>directly
>> > > applicable to Martyn's issue, but there is a common confusion
>about the
>> > > value of the summing resistors.
>> > >
>> > > Per Tom Clark, who came up with the idea, they are*not*  intended
>to
>> > > provide a near-end line termination to 50 ohms, but are simply
>there to
>> > > protect the paralleled devices if the gates have slightly
>different
>> > > delays (in which case one gate could end up sinking the other
>two).
>> > >
>> > > So, the commonly used 47 ohm value isn't magic.  You can use a
>lower
>> > > value, and thus get more voltage at the far end.  I haven't
>> experimented
>> > > to see how far you can take that idea before destroying gates.
>> > >
>> > > John
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 6
>> > Date: Wed, 04 Mar 2015 17:44:09 -0600
>> > From: Didier Juges <shalimr9 at gmail.com>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] Trimble Thunderbolt NMEA ?
>> > Message-ID: <EF4EDC38-C96B-402F-AB2F-9AC273AB399C at gmail.com>
>> > Content-Type: text/plain; charset=UTF-8
>> >
>> > The code is in C and Silabs has small dev kits (Toolsticks) that
>cost $10
>> > to which you need to add $18 for the programming dongle. A little
>more
>> > expensive than an Arduino, or less, depending on where you buy
>it...
>> >
>> > To that you need to add a MAX232 (or two serial-TTL adapters at $4
>each
>> or
>> > so on ebay) and you are in business.
>> >
>> > Total cost about the same as a dedicated GPS receiver with antenna
>and
>> > NMEA output. Choose your poison :)
>> >
>> > Didier KO4BB
>> >
>> >
>> > On March 3, 2015 10:23:56 PM CST, Chris Albertson <
>> > albertson.chris at gmail.com> wrote:
>> > >Is the code in C?  If so I bet it would run on some development
>board.
>> > >No
>> > >need to make custom PCBs.
>> > >
>> > >On Tue, Mar 3, 2015 at 5:00 AM, Didier Juges <shalimr9 at gmail.com>
>> > >wrote:
>> > >
>> > >> Tim,
>> > >>
>> > >> It shouldn't be too hard to modify the code for my Thunderbolt
>> > >monitor to
>> > >> make it into a TSIP->NMEA converter. The last version of the kit
>has
>> > >a uC
>> > >> with two serial ports. I m out of the kits at the moment but I
>have a
>> > >few
>> > >> spare boards left over.
>> > >>
>> > >
>> > >--
>> > >
>> > >Chris Albertson
>> > >Redondo Beach, California
>> > >_______________________________________________
>> > >time-nuts mailing list -- time-nuts at febo.com
>> > >To unsubscribe, go to
>> > >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > >and follow the instructions there.
>> >
>> > --
>> > Sent from my Motorola Droid Razr HD 4G LTE wireless tracker while I
>do
>> > other things.
>> >
>> > ------------------------------
>> >
>> > Message: 7
>> > Date: Wed, 4 Mar 2015 18:47:13 -0500
>> > From: Bob Camp <kb8tq at n1k.org>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID: <EFC260CC-CAF3-4021-8EF9-27540AE57494 at n1k.org>
>> > Content-Type: text/plain; charset=utf-8
>> >
>> > Hi
>> >
>> > If you want to drive out of a 50 ohm source into your 50 ohm load
>*and*
>> > get 5V into the load … that’s a fancy amp. 10V power and some
>careful
>> > work to get it going.
>> >
>> > If you just want to get roughly 5V into a 50 ohm load, then it’s a
>matter
>> > of how
>> > many gates you decide to parallel. If you go with “32 ma” drivers,
>you
>> > should
>> > be able to get it done with 8 of them in parallel. Drive them all
>off of
>> a
>> > single
>> > dedicated fast gate that’s on the same supply. Probably best to
>stuff
>> > a 20 or 30 ohm resistor in series with each of the outputs. If it’s
>*got*
>> > to
>> > be a full 5V, don’t use the resistors.
>> >
>> > Bob
>> >
>> > > On Mar 4, 2015, at 5:26 AM, Martyn Smith <martyn at ptsyst.com>
>wrote:
>> > >
>> > > Hello,
>> > >
>> > > A quick question.
>> > >
>> > > My output driver for a simple amplifier.
>> > >
>> > > I use three gates (in parallel with resistors) from a 74AC14 to
>give me
>> > about 0-3.2V into 50 ohm.
>> > >
>> > > I want to have a driver that gives me a full 0-5V (at least
>0-4.5V)
>> > swing into 50 ohms.
>> > >
>> > > Can anyone recommend an IC that can delivery this.
>> > >
>> > > But it needs to have similar jitter performance to the 74AC14.
>> > >
>> > > I use it up to 10 MHz.
>> > >
>> > > Best Regards
>> > >
>> > > Martyn
>> > >
>> > > _______________________________________________
>> > > time-nuts mailing list -- time-nuts at febo.com
>> > > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > > and follow the instructions there.
>> >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 8
>> > Date: Wed, 04 Mar 2015 19:44:29 -0500
>> > From: Charles Steinmetz <csteinmetz at yandex.com>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] 50 ohm Driver
>> > Message-ID: <20150305034434.iYveMp4n at smtp12.mail.yandex.net>
>> > Content-Type: text/plain; charset="us-ascii"; format=flowed
>> >
>> >
>> > >Is [one gate sourcing or sinking current into paralleled gates
>that
>> > >don't switch at
>> > >exactly the same time] a real problem?  How far off can the prop
>> > >delay be for 2
>> > >gates on the same chip?
>> > >
>> > >I seem to remember reading something saying it was OK to just wire
>them
>> > up in
>> > >parallel.  It could have been an app note, or it could have been a
>rumor
>> > on
>> > >usenet.
>> >
>> > Most manufacturers sanction direct paralleling of gates on the same
>> > chip (and forbid any paralleling, ballasted or otherwise, of
>outputs
>> > from different chips).  However, there are other considerations
>> > (short-circuit protection, maximum output current rating per gate,
>> > maximum supply and/or ground current rating per package, maximum
>> > power dissipation, etc.).  Good design practice is to put series
>> > resistors on each gate output that will prevent any of these
>ratings
>> > from being exceeded into a short circuit to ground or to Vcc.  For
>> > HC, AC, NC7NZ, and NC7SZ, the per-gate output current rating is +/-
>> > 24 (or 25) mA, which suggests that each gate should have a 200 ohm
>> > series resistor -- but you need to check all of the other ratings
>> > mentioned above for the chip you use, to make sure they won't be
>> violated.
>> >
>> > Unfortunately, if the load is 50 ohms to ground, pulling it to even
>> > 4.5v from a 5v logic supply requires a source resistance of only
>5.6
>> > ohms, or 36 parallel gates each with 200 ohms in series (this
>assumes
>> > that the gates can pull all the way to 5v while delivering rated
>> > current, which they can't -- so the reality is even worse).  You
>can
>> > make things a little better by terminating the output into 50 ohms
>to
>> > 1/2 Vcc (i.e, the center of a voltage divider with 100 ohms to Vcc
>> > and 100 ohms to ground), but (i) it only gets a little better, and
>> > (ii) now it won't pull all the way to ground.
>> >
>> > All that said, why do you want to generate a high-current square
>> > wave, anyway?  If you're distributing a frequency standard, it is
>> > much better to distribute a sine wave (you don't have to worry
>about
>> > the harmonics being skewed, and there is exponentially less of a
>> > problem with it radiating and getting into every radio and other
>> > sensitive electronic device in your house and the other houses on
>the
>> > block).
>> >
>> > Best regards,
>> >
>> > Charles
>> >
>> >
>> >
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 9
>> > Date: Thu, 05 Mar 2015 01:27:23 +0000
>> > From: Angus <not.again at btinternet.com>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] new tdc from Texas
>> > Message-ID: <uu9ffapgkl5t7qnv73m9v7j2ba5mttl0u6 at 4ax.com>
>> > Content-Type: text/plain; charset=us-ascii
>> >
>> > Hi,
>> >
>> > I've not seen any mention of anything other than the TDC1000.
>> >
>> > I was a bit surprised that they went down the less-integrated route
>> > and separated the TDC, but it turns out that for a lot of the sort
>of
>> > things they designed it for, a uC provides good enough timing
>itself,
>> > and no extra TDC is needed at all.
>> >
>> > I see that Acam have released a bit more info on their new GP30,
>> > although no data sheet yet. It quotes typical LSB of 11ps, and rms
>> > noise of 1.2 LSB, which is quite an improvement on the GP22.
>> > It would just be good if they offered a simple online way of
>getting
>> > low volumes of them - I suspect that the specialist distributors
>would
>> > be just as happy as the customers would be!
>> >
>> > Angus.
>> >
>> >
>> > On Tue, 03 Mar 2015 15:43:25 -0800, you wrote:
>> >
>> > >Hi Angus:
>> > >
>> > >Do you know if they have an IR pulse front end which would be more
>> > interesting than the ultrasonic front end?
>> > >
>> > >Mail_Attachment --
>> > >Have Fun,
>> > >
>> > >Brooke Clarke
>> > >http://www.PRC68.com
>> > >http://www.end2partygovernment.com/2012Issues.html
>> > >http://www.prc68.com/I/DietNutrition.html
>> > >Angus wrote:
>> > >> In case anyone is interested, the full data sheet is on the TI
>site
>> > >> now, although I didn't see any actual IC's yet other than the
>ones in
>> > >> the eval boards.
>> > >>
>> > >> Angus.
>> > >>
>> > >>
>> > >> On Tue, 17 Feb 2015 21:24:08 -0200, you wrote:
>> > >>
>> > >>> Initial datasheet:
>> > >>>
>> > >>> http://www.ti.com/lit/ds/symlink/tdc7200.pdf
>> > >>>
>> > >>> EVM:
>> > >>>
>> > >>> http://www.ti.com/tool/tdc1000-tdc7200evm
>> > >>>
>> > >>> Seems good... what do you think?
>> > >>>
>> > >>> Daniel
>> > >>> _______________________________________________
>> > >>> time-nuts mailing list -- time-nuts at 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 at 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 at febo.com
>> > >To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > >and follow the instructions there.
>> >
>> >
>> > ------------------------------
>> >
>> > Message: 10
>> > Date: Thu, 5 Mar 2015 08:56:23 +0100
>> > From: Attila Kinali <attila at kinali.ch>
>> > To: Discussion of precise time and frequency measurement
>> > <time-nuts at febo.com>
>> > Subject: Re: [time-nuts] new tdc from Texas
>> > Message-ID: <20150305085623.cb5218ab541d5ffaf13dcfcb at kinali.ch>
>> > Content-Type: text/plain; charset=US-ASCII
>> >
>> > On Thu, 05 Mar 2015 01:27:23 +0000
>> > Angus <not.again at btinternet.com> wrote:
>> >
>> > > I've not seen any mention of anything other than the TDC1000.
>> > >
>> > > I was a bit surprised that they went down the less-integrated
>route
>> > > and separated the TDC, but it turns out that for a lot of the
>sort of
>> > > things they designed it for, a uC provides good enough timing
>itself,
>> > > and no extra TDC is needed at all.
>> >
>> > I think the main application TI intended it for is for ultrasonic
>> > flow meeters (like [1]). There you have quite small and bounded
>> > start-stop delays. With this they can get into the growing
>electronics
>> > for low energy building market.
>> >
>> > In contrast to that, the Acam devices seem to be general purpose
>TDCs
>> >
>> >
>> > Attila Kinali
>> >
>> >
>> > [1] http://www.shk-profi.de/imgs/52579203_0d4dd378d4.jpg
>> > --
>> > < _av500_> phd is easy
>> > < _av500_> getting dsl is hard
>> >
>> >
>> > ------------------------------
>> >
>> > Subject: Digest Footer
>> >
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>> > ------------------------------
>> >
>> > End of time-nuts Digest, Vol 128, Issue 5
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