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Discussion of precise time and frequency measurement

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LT1016 as a pulse shaper...

UK
Ulf Kylenfall
Sat, Mar 3, 2018 5:08 PM

Gentlemen,
I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
Ulf Kylenfall
SM6GXV

Gentlemen, I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? Ulf Kylenfall SM6GXV
DC
David C. Partridge
Sat, Mar 3, 2018 5:38 PM

You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

I've seen documents saying that using fast logic gates can result in lower jitter/phase noise.  Bruce - do you know ?

David

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
Sent: 03 March 2018 17:08
To: Discussion of Precise Time and Frequency Measurement
Subject: [time-nuts] LT1016 as a pulse shaper...

Gentlemen,
I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
Ulf Kylenfall
SM6GXV

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.

You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? David -----Original Message----- From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts Sent: 03 March 2018 17:08 To: Discussion of Precise Time and Frequency Measurement Subject: [time-nuts] LT1016 as a pulse shaper... Gentlemen, I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? Ulf Kylenfall SM6GXV _______________________________________________ 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.
MG
Mark Goldberg
Sat, Mar 3, 2018 5:55 PM

Search for ultra fast comparator yields TL3016 and AD8611, claims to be
faster pin compatible replacements.  I have found low parasitic capacitance
on the outputs of these types of comparators is important, and I have used
balanced hysteresis (use positive feedback from both + and - outputs). I
haven't needed jitter lower than 10 ns or so, with awful inputs, so have
not optimized for lower jitter.

Search google for "ultra fast comparator" and several turn up that are in
the low ns or hundreds of ps range for prop delay. ADCMP566, TL3116,
LMH7322, LTC6752, MAX9691 turn up among others. I haven't investigated or
used any of them.

Regards,

Mark Goldberg

On Sat, Mar 3, 2018 at 10:08 AM, Ulf Kylenfall via time-nuts <
time-nuts@febo.com> wrote:

Gentlemen,
I have so far been using LT1016 as a pulse shaper and also whenever I
needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all
the decouplingand layout precautions as recommended by LT.
Are there any similar or better alternatives out there that could be
usedthat would provide lower jitter and that are less expenceive?
Ulf Kylenfall
SM6GXV

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.

Search for ultra fast comparator yields TL3016 and AD8611, claims to be faster pin compatible replacements. I have found low parasitic capacitance on the outputs of these types of comparators is important, and I have used balanced hysteresis (use positive feedback from both + and - outputs). I haven't needed jitter lower than 10 ns or so, with awful inputs, so have not optimized for lower jitter. Search google for "ultra fast comparator" and several turn up that are in the low ns or hundreds of ps range for prop delay. ADCMP566, TL3116, LMH7322, LTC6752, MAX9691 turn up among others. I haven't investigated or used any of them. Regards, Mark Goldberg On Sat, Mar 3, 2018 at 10:08 AM, Ulf Kylenfall via time-nuts < time-nuts@febo.com> wrote: > > Gentlemen, > I have so far been using LT1016 as a pulse shaper and also whenever I > needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all > the decouplingand layout precautions as recommended by LT. > Are there any similar or better alternatives out there that could be > usedthat would provide lower jitter and that are less expenceive? > Ulf Kylenfall > SM6GXV > _______________________________________________ > 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. >
BG
Bruce Griffiths
Sat, Mar 3, 2018 9:34 PM

Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above.

Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list.

Bruce

 On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote:

 You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

 They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

 I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ?

 David

 -----Original Message-----
 From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
 Sent: 03 March 2018 17:08
 To: Discussion of Precise Time and Frequency Measurement
 Subject: [time-nuts] LT1016 as a pulse shaper...

 Gentlemen,
 I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
 Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
 Ulf Kylenfall
 SM6GXV

 _______________________________________________
 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.
Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above. Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list. Bruce > > On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote: > > You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. > > They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. > > I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? > > David > > -----Original Message----- > From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts > Sent: 03 March 2018 17:08 > To: Discussion of Precise Time and Frequency Measurement > Subject: [time-nuts] LT1016 as a pulse shaper... > > Gentlemen, > I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. > Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? > Ulf Kylenfall > SM6GXV > > _______________________________________________ > 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. >
BK
Bob kb8tq
Sat, Mar 3, 2018 9:56 PM

Hi

If you are simply dealing with 10 MHz sine waves (as many of us are).

— and —

It’s a “matched” application ( = you know the level / the source and converter are tied together)

— and —

You don’t mind an L network to match increase the Vpp when it goes to the gate

— and —

Once the performance of the circuit is better than any source you can drive it with, you
don’t care. ( = you only care if it degrades the signal)

You can do a very good job with a biased CMOS gate. Running at 5V (or even better 5.5)
will out perform 3.3V. They are dirt cheap. They are easy to solder down in SOT-23 packages.
They are reasonably robust in terms of overload. They perform pretty well when under driven
by modest amounts. They have nice short delay paths.

What’s not to like :)

Bob

On Mar 3, 2018, at 4:34 PM, Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:

Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above.

Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list.

Bruce

On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote:

You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ?

David

-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
Sent: 03 March 2018 17:08
To: Discussion of Precise Time and Frequency Measurement
Subject: [time-nuts] LT1016 as a pulse shaper...

Gentlemen,
I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
Ulf Kylenfall
SM6GXV

_______________________________________________
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.

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.

Hi If you are simply dealing with 10 MHz sine waves (as many of us are). — and — It’s a “matched” application ( = you know the level / the source and converter are tied together) — and — You don’t mind an L network to match increase the Vpp when it goes to the gate — and — Once the performance of the circuit is better than any source you can drive it with, you don’t care. ( = you only care if it degrades the signal) You can do a very good job with a biased CMOS gate. Running at 5V (or even better 5.5) will out perform 3.3V. They are dirt cheap. They are easy to solder down in SOT-23 packages. They are reasonably robust in terms of overload. They perform pretty well when under driven by modest amounts. They have nice short delay paths. What’s not to like :) Bob > On Mar 3, 2018, at 4:34 PM, Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > > Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above. > > Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list. > > Bruce > >> >> On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote: >> >> You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. >> >> They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. >> >> I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? >> >> David >> >> -----Original Message----- >> From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts >> Sent: 03 March 2018 17:08 >> To: Discussion of Precise Time and Frequency Measurement >> Subject: [time-nuts] LT1016 as a pulse shaper... >> >> Gentlemen, >> I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. >> Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? >> Ulf Kylenfall >> SM6GXV >> >> _______________________________________________ >> 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. >> > _______________________________________________ > 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.
BG
Bruce Griffiths
Sat, Mar 3, 2018 9:56 PM

Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases.

Bruce

 On 04 March 2018 at 10:34 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote:

 Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above.

 Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list.

 Bruce

     On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote:

     You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

     They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

     I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ?

     David

     -----Original Message-----
     From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
     Sent: 03 March 2018 17:08
     To: Discussion of Precise Time and Frequency Measurement
     Subject: [time-nuts] LT1016 as a pulse shaper...

     Gentlemen,
     I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
     Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
     Ulf Kylenfall
     SM6GXV

     _______________________________________________
     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.

     _______________________________________________
     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.
Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases. Bruce > > On 04 March 2018 at 10:34 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > > Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above. > > Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list. > > Bruce > > > > > > On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote: > > > > You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. > > > > They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. > > > > I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? > > > > David > > > > -----Original Message----- > > From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts > > Sent: 03 March 2018 17:08 > > To: Discussion of Precise Time and Frequency Measurement > > Subject: [time-nuts] LT1016 as a pulse shaper... > > > > Gentlemen, > > I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. > > Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? > > Ulf Kylenfall > > SM6GXV > > > > _______________________________________________ > > 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. > > > > _______________________________________________ > > 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. > > > > >
E
ewkehren
Sat, Mar 3, 2018 10:29 PM

We only use three circuits Wenzel sn65ELT35 and LTC6957. For critical applications it is the LTC we refer to it in our designs the Bruce circuit the only problem is solderability, my eyes. Bought 25, to poor to buy junk and not smart  enough to select something less in critical applications.        Bert Kehren

Sent from my Galaxy Tab® A
-------- Original message --------From: Bruce Griffiths bruce.griffiths@xtra.co.nz Date: 3/3/18  4:56 PM  (GMT-05:00) To: "David C. Partridge" david.partridge@perdrix.co.uk, Discussion of precise time and frequency measurement time-nuts@febo.com, Ulf Kylenfall ulf_r_k@yahoo.com Subject: Re: [time-nuts] LT1016 as a pulse shaper...
Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases.

Bruce

     On 04 March 2018 at 10:34 Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:

     Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above.

     Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list.

     Bruce

         > >

         On 04 March 2018 at 06:38 "David C. Partridge" david.partridge@perdrix.co.uk wrote:

         You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

         They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

         I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ?

         David

         -----Original Message-----
         From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
         Sent: 03 March 2018 17:08
         To: Discussion of Precise Time and Frequency Measurement
         Subject: [time-nuts] LT1016 as a pulse shaper...

         Gentlemen,
         I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
         Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
         Ulf Kylenfall
         SM6GXV

         _______________________________________________
         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.

         _______________________________________________
         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.

We only use three circuits Wenzel sn65ELT35 and LTC6957. For critical applications it is the LTC we refer to it in our designs the Bruce circuit the only problem is solderability, my eyes. Bought 25, to poor to buy junk and not smart  enough to select something less in critical applications.        Bert Kehren Sent from my Galaxy Tab® A -------- Original message --------From: Bruce Griffiths <bruce.griffiths@xtra.co.nz> Date: 3/3/18 4:56 PM (GMT-05:00) To: "David C. Partridge" <david.partridge@perdrix.co.uk>, Discussion of precise time and frequency measurement <time-nuts@febo.com>, Ulf Kylenfall <ulf_r_k@yahoo.com> Subject: Re: [time-nuts] LT1016 as a pulse shaper... Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases. Bruce > >     On 04 March 2018 at 10:34 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > >     Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above. > >     Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list. > >     Bruce > >         > > > >         On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote: > > > >         You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. > > > >         They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. > > > >         I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? > > > >         David > > > >         -----Original Message----- > >         From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts > >         Sent: 03 March 2018 17:08 > >         To: Discussion of Precise Time and Frequency Measurement > >         Subject: [time-nuts] LT1016 as a pulse shaper... > > > >         Gentlemen, > >         I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. > >         Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? > >         Ulf Kylenfall > >         SM6GXV > > > >         _______________________________________________ > >         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. > > > >         _______________________________________________ > >         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.
BG
Bruce Griffiths
Sun, Mar 4, 2018 1:52 AM

The attached circuit is suitable for testing the PN of various CMOS inveters etc used as sine to CMOS converters.
Just adjust the input LC network and resistors to suit the source, frequency, power and CMOS device Vcc.
Select  the resistor in series with the CMOS output to produce a total series R ~ 68 ohms when the CMOS device output R is included. Some fast CMOS devices (esp clock drivers) have an output R close to 50 ohms as they are intended to drive 50 ohm source terminated transmision lines.
Output network LC values are selected to suit the output frequency of the CMOS device.

Bruce

On 04 March 2018 at 10:56 Bruce Griffiths bruce.griffiths@xtra.co.nz wrote:

Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases.

Bruce

 On 04 March 2018 at 10:34 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote:

 Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above.

 Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list.

 Bruce

     On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote:

     You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels.

     They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed.

     I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ?

     David

     -----Original Message-----
     From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts
     Sent: 03 March 2018 17:08
     To: Discussion of Precise Time and Frequency Measurement
     Subject: [time-nuts] LT1016 as a pulse shaper...

     Gentlemen,
     I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT.
     Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive?
     Ulf Kylenfall
     SM6GXV

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The attached circuit is suitable for testing the PN of various CMOS inveters etc used as sine to CMOS converters. Just adjust the input LC network and resistors to suit the source, frequency, power and CMOS device Vcc. Select the resistor in series with the CMOS output to produce a total series R ~ 68 ohms when the CMOS device output R is included. Some fast CMOS devices (esp clock drivers) have an output R close to 50 ohms as they are intended to drive 50 ohm source terminated transmision lines. Output network LC values are selected to suit the output frequency of the CMOS device. Bruce > On 04 March 2018 at 10:56 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > > > Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which increases as the amount of hysteresis increases. > > > Bruce > > > > > On 04 March 2018 at 10:34 Bruce Griffiths <bruce.griffiths@xtra.co.nz> wrote: > > > > Ideally one should use a Collins style optimised cascade of increasing bandwidth and gain limiting stages. The LTC6957 with its selectable input stage bandwidth has a performance that is comparable with the Holzworth sine to CMOS "amplifier" which is better than any comparator by itself. If the amplitude of the input signal is large enough (i.e. input slew rate seen by the gate is large enough) the performance of a single CMOS gate can be very good. However the performance of current CMOS gates degrades in this application with input frequencies of 100MHz and above. > > > > Measuring the PN performance of CMOS gates used as sine to CMOS converters is on the todo list. > > > > Bruce > > > > > > > > > On 04 March 2018 at 06:38 "David C. Partridge" <david.partridge@perdrix.co.uk> wrote: > > > > > > You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting buffers) depending on the exact voltage levels. > > > > > > They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or SOT23-5 case and can drive 25mA output if needed. > > > > > > I've seen documents saying that using fast logic gates can result in lower jitter/phase noise. Bruce - do you know ? > > > > > > David > > > > > > -----Original Message----- > > > From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Ulf Kylenfall via time-nuts > > > Sent: 03 March 2018 17:08 > > > To: Discussion of Precise Time and Frequency Measurement > > > Subject: [time-nuts] LT1016 as a pulse shaper... > > > > > > Gentlemen, > > > I have so far been using LT1016 as a pulse shaper and also whenever I needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all the decouplingand layout precautions as recommended by LT. > > > Are there any similar or better alternatives out there that could be usedthat would provide lower jitter and that are less expenceive? > > > Ulf Kylenfall > > > SM6GXV > > > > > > _______________________________________________ > > > 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. > > > > > > _______________________________________________ > > > 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.
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