On Thu, 07 Mar 2013 14:48:53 -0800, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Thu, 07 Mar 2013 16:36:35 -0600, John Fields <jfields@austininstruments.com> >wrote: > >>On Thu, 07 Mar 2013 13:32:22 -0800, John Larkin >><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>>>Post something better. >> >>--- >>OK, >> >>From "Einstein's Theory of Relativity" by Max Born, we have: >> v� >>sqrt (1-beta�) = sqrt 1- --- >> ac� > >What a sad old dork.--- Commentary, but nothing relevant... -- JF
Simple pulse stretcher
Started by ●March 7, 2013
Reply by ●March 7, 20132013-03-07
Reply by ●March 7, 20132013-03-07
On Thu, 07 Mar 2013 17:02:37 -0600, John Fields <jfields@austininstruments.com> wrote:>On Thu, 07 Mar 2013 14:48:53 -0800, John Larkin ><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > >>On Thu, 07 Mar 2013 16:36:35 -0600, John Fields <jfields@austininstruments.com> >>wrote: >> >>>On Thu, 07 Mar 2013 13:32:22 -0800, John Larkin >>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > >>>>Post something better. >>> >>>--- >>>OK, >>> >>>From "Einstein's Theory of Relativity" by Max Born, we have: >>> v� >>>sqrt (1-beta�) = sqrt 1- --- >>> ac� >> >>What a sad old dork. > >--- >Commentary, but nothing relevant...Another one of JL's non-working "designs". A quick check of 74HC proves my supposition that a 5ns wide pulse goes nowhere... at least reliably... something JL never worries about... but that's what you get when you're pompously ignorant. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●March 7, 20132013-03-07
George Herold wrote:> Hi guys, I need a little digital pulse stretcher. I've got pulses > that are 5ns to 25ns in width, and I'd like to bump them all up to all > be at least 10ns. I've got a few spare 74HC14 inverters. I was > thinking of just feeding one through a diode followed by an R/C to > ground. Any other ways? There might be an extra AND gate too. > (not my circuit so I'm not quite sure.) > > Thanks > > George H. > (and who ordered the second t in stretcher)I think you're going to have a little problem with that inverter in regards to the speed you are referring to. Jamie
Reply by ●March 7, 20132013-03-07
On Thu, 07 Mar 2013 16:19:36 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Thu, 07 Mar 2013 17:02:37 -0600, John Fields ><jfields@austininstruments.com> wrote: > >>On Thu, 07 Mar 2013 14:48:53 -0800, John Larkin >><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Thu, 07 Mar 2013 16:36:35 -0600, John Fields <jfields@austininstruments.com> >>>wrote: >>> >>>>On Thu, 07 Mar 2013 13:32:22 -0800, John Larkin >>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >> >>>>>Post something better. >>>> >>>>--- >>>>OK, >>>> >>>>From "Einstein's Theory of Relativity" by Max Born, we have: >>>> v� >>>>sqrt (1-beta�) = sqrt 1- --- >>>> ac� >>> >>>What a sad old dork. >> >>--- >>Commentary, but nothing relevant... > >Another one of JL's non-working "designs". A quick check of 74HC >proves my supposition that a 5ns wide pulse goes nowhere... at least >reliably... something JL never worries about... but that's what you >get when you're pompously ignorant. > > ...Jim ThompsonI didn't say it was a 74HC, much less an HC14. Note that the delay elements are non-inverting. Having no ideas of your own, you two old hens are naturally hostile to ideas. Design an original pulse stretcher concept, if you can. Post it here. This one makes pulses adjustable from 100 ps to 25 ns. How would you do that? http://www.highlandtechnology.com/DSS/T240DS.shtml -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Reply by ●March 7, 20132013-03-07
On Thursday, March 7, 2013 1:21:33 PM UTC-5, George Herold wrote:> Hi guys, I need a little digital pulse stretcher. I've got pulses >=20 > that are 5ns to 25ns in width, and I'd like to bump them all up to all >=20 > be at least 10ns. I've got a few spare 74HC14 inverters. I was >=20 > thinking of just feeding one through a diode followed by an R/C to >=20 > ground. Any other ways? There might be an extra AND gate too. >=20 > (not my circuit so I'm not quite sure.) >=20The 5ns is way out of line for HC. You can apply the pulse directly to an e= mitter follower loaded with parallel RC and then to HC to stretch it to any= width you want. The BE junction is your diode. HC will not work reliably a= cross VCC and temperature with anything less than about 25ns.
Reply by ●March 7, 20132013-03-07
On Mar 7, 3:43=A0pm, John Fields <jfie...@austininstruments.com> wrote:> On Thu, 7 Mar 2013 10:21:33 -0800 (PST), George Herold > > <gher...@teachspin.com> wrote: > >Hi guys, =A0I need a little digital pulse stretcher. =A0I've got pulses > >that are 5ns to 25ns in width, and I'd like to bump them all up to all > >be at least 10ns. =A0 I've got a few spare 74HC14 inverters. =A0I was > >thinking of just feeding one through a diode followed by an R/C to > >ground. =A0Any other ways? =A0There might be an extra AND gate too. > >(not my circuit so I'm not quite sure.) > > >Thanks > > >George H. > >(and who ordered the second t in stretcher) > > --- > "Pulse stretcher" implies that the leading edge of the source pulse > should be presented at the input of the load simultaneously with its > generation, and that its fall should occur after the desired delay. > > The former is, of course, unrealizable, while the latter is easy. > > How much delay can you tolerate between the generation of the leading > edge of the source pulse and its presentation to the load? > > -- > JFYeah there's already ~20ns of latency between the input pulse and the output so a bit extra ain't too bad. I'll knock the 10pF down to 4.7 George H.
Reply by ●March 7, 20132013-03-07
On Mar 7, 3:56=A0pm, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:> On Thu, 7 Mar 2013 11:01:25 -0800 (PST), George Herold <gher...@teachspin=.com>> wrote: > > > > > > >On Mar 7, 1:33=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My- > >Web-Site.com> wrote: > >> On Thu, 7 Mar 2013 10:21:33 -0800 (PST), George Herold > > >> <gher...@teachspin.com> wrote: > >> >Hi guys, =A0I need a little digital pulse stretcher. =A0I've got puls=es> >> >that are 5ns to 25ns in width, and I'd like to bump them all up to al=l> >> >be at least 10ns. =A0 I've got a few spare 74HC14 inverters. =A0I was > >> >thinking of just feeding one through a diode followed by an R/C to > >> >ground. =A0Any other ways? =A0There might be an extra AND gate too. > >> >(not my circuit so I'm not quite sure.) > > >> >Thanks > > >> >George H. > >> >(and who ordered the second t in stretcher) > > >> Isn't 10ns width just a wee-bit tight for 74HC parts? > > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 ...Jim Thompson> >> -- > >> | James E.Thompson =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0==A0 =A0 =A0 | =A0 =A0mens =A0 =A0 |> >> | Analog Innovations =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 | =A0 =A0 et =A0 =A0 =A0|> >> | Analog/Mixed-Signal ASIC's and Discrete Systems =A0| =A0 =A0manus ==A0 =A0|> >> | Phoenix, Arizona =A085048 =A0 =A0Skype: Contacts Only =A0| =A0 =A0 ==A0 =A0 =A0 =A0 |> >> | Voice:(480)460-2350 =A0Fax: Available upon request | =A0Brass Rat ==A0|> >> | E-mail Icon athttp://www.analog-innovations.com|=A0 =A01962 =A0 =A0 =|> > >> I love to cook with wine. =A0 =A0 Sometimes I even put it in the food. > > >OK, maybe I should stretch to 20 ns. > > >George H. > > The diode+RC thing is perfectly feasible with an HC14, likely at 20 ns ou=t and> certainly at 30. > > A bit of inductance in series with the R would be interesting. > > Here's a variation on Vlad's circuit: > > https://dl.dropbox.com/u/53724080/SED/Stretcher.JPG > > -- > > John Larkin =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Highland Technology Incwww=.highlandtechnology.com=A0 jlarkin at highlandtechnology dot com> > Precision electronic instrumentation > Picosecond-resolution Digital Delay and Pulse generators > Custom timing and laser controllers > Photonics and fiberoptic TTL data links > VME =A0analog, thermocouple, LVDT, synchro, tachometer > Multichannel arbitrary waveform generators- Hide quoted text - > > - Show quoted text -Whee... fun! George H.
Reply by ●March 7, 20132013-03-07
On Mar 7, 4:08=A0pm, John Fields <jfie...@austininstruments.com> wrote:> On Thu, 07 Mar 2013 12:56:22 -0800, John Larkin > > > > > > <jjlar...@highNOTlandTHIStechnologyPART.com> wrote: > >On Thu, 7 Mar 2013 11:01:25 -0800 (PST), George Herold <gher...@teachspi=n.com>> >wrote: > > >>On Mar 7, 1:33=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My=-> >>Web-Site.com> wrote: > >>> On Thu, 7 Mar 2013 10:21:33 -0800 (PST), George Herold > > >>> <gher...@teachspin.com> wrote: > >>> >Hi guys, =A0I need a little digital pulse stretcher. =A0I've got pul=ses> >>> >that are 5ns to 25ns in width, and I'd like to bump them all up to a=ll> >>> >be at least 10ns. =A0 I've got a few spare 74HC14 inverters. =A0I wa=s> >>> >thinking of just feeding one through a diode followed by an R/C to > >>> >ground. =A0Any other ways? =A0There might be an extra AND gate too. > >>> >(not my circuit so I'm not quite sure.) > > >>> >Thanks > > >>> >George H. > >>> >(and who ordered the second t in stretcher) > > >>> Isn't 10ns width just a wee-bit tight for 74HC parts? > > >>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 ...Jim Thompson> >>> -- > >>> | James E.Thompson =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 =A0 | =A0 =A0mens =A0 =A0 |> >>> | Analog Innovations =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 | =A0 =A0 et =A0 =A0 =A0|> >>> | Analog/Mixed-Signal ASIC's and Discrete Systems =A0| =A0 =A0manus ==A0 =A0|> >>> | Phoenix, Arizona =A085048 =A0 =A0Skype: Contacts Only =A0| =A0 =A0 ==A0 =A0 =A0 =A0 |> >>> | Voice:(480)460-2350 =A0Fax: Available upon request | =A0Brass Rat ==A0|> >>> | E-mail Icon athttp://www.analog-innovations.com|=A0 =A01962 =A0 =A0=|> > >>> I love to cook with wine. =A0 =A0 Sometimes I even put it in the food=.> > >>OK, maybe I should stretch to 20 ns. > > >>George H. > > >The diode+RC thing is perfectly feasible with an HC14, likely at 20 ns o=ut and> >certainly at 30. > > >A bit of inductance in series with the R would be interesting. > > >Here's a variation on Vlad's circuit: > > >https://dl.dropbox.com/u/53724080/SED/Stretcher.JPG > > --- > You've still got the initial gate delay from input to output, and the > prop delay through the buffers isn't exactly precise... > > -- > JF- Hide quoted text - > > - Show quoted text -Yeah in this case there's certainly already some delay. But it doesn't really matter. OK it matters.. it all adds to the built in latency of the device. But at the moment there's some 'software' latency that's ~x10's as bad. So I can burn 10's of nanoseconds with abandon. George H.
Reply by ●March 7, 20132013-03-07
On 3/7/2013 8:43 PM, bloggs.fredbloggs.fred@gmail.com wrote:> On Thursday, March 7, 2013 1:21:33 PM UTC-5, George Herold wrote: >> Hi guys, I need a little digital pulse stretcher. I've got >> pulses >> >> that are 5ns to 25ns in width, and I'd like to bump them all up to >> all >> >> be at least 10ns. I've got a few spare 74HC14 inverters. I was >> >> thinking of just feeding one through a diode followed by an R/C to >> >> ground. Any other ways? There might be an extra AND gate too. >> >> (not my circuit so I'm not quite sure.) >> > > The 5ns is way out of line for HC.The 5...6 ns per gate is what you can practically expect from today's HC. VLV
Reply by ●March 7, 20132013-03-07
On Mar 7, 4:32=A0pm, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:> On Thu, 07 Mar 2013 15:08:49 -0600, John Fields <jfie...@austininstrument=s.com>> wrote: > > > > > > >On Thu, 07 Mar 2013 12:56:22 -0800, John Larkin > ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: > > >>On Thu, 7 Mar 2013 11:01:25 -0800 (PST), George Herold <gher...@teachsp=in.com>> >>wrote: > > >>>On Mar 7, 1:33=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-M=y-> >>>Web-Site.com> wrote: > >>>> On Thu, 7 Mar 2013 10:21:33 -0800 (PST), George Herold > > >>>> <gher...@teachspin.com> wrote: > >>>> >Hi guys, =A0I need a little digital pulse stretcher. =A0I've got pu=lses> >>>> >that are 5ns to 25ns in width, and I'd like to bump them all up to =all> >>>> >be at least 10ns. =A0 I've got a few spare 74HC14 inverters. =A0I w=as> >>>> >thinking of just feeding one through a diode followed by an R/C to > >>>> >ground. =A0Any other ways? =A0There might be an extra AND gate too. > >>>> >(not my circuit so I'm not quite sure.) > > >>>> >Thanks > > >>>> >George H. > >>>> >(and who ordered the second t in stretcher) > > >>>> Isn't 10ns width just a wee-bit tight for 74HC parts? > > >>>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 ...Jim Thompson> >>>> -- > >>>> | James E.Thompson =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 =A0 =A0 | =A0 =A0mens =A0 =A0 |> >>>> | Analog Innovations =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0==A0 =A0 =A0 | =A0 =A0 et =A0 =A0 =A0|> >>>> | Analog/Mixed-Signal ASIC's and Discrete Systems =A0| =A0 =A0manus ==A0 =A0|> >>>> | Phoenix, Arizona =A085048 =A0 =A0Skype: Contacts Only =A0| =A0 =A0==A0 =A0 =A0 =A0 |> >>>> | Voice:(480)460-2350 =A0Fax: Available upon request | =A0Brass Rat ==A0|> >>>> | E-mail Icon athttp://www.analog-innovations.com|=A0 =A01962 =A0 ==A0 |> > >>>> I love to cook with wine. =A0 =A0 Sometimes I even put it in the foo=d.> > >>>OK, maybe I should stretch to 20 ns. > > >>>George H. > > >>The diode+RC thing is perfectly feasible with an HC14, likely at 20 ns =out and> >>certainly at 30. > > >>A bit of inductance in series with the R would be interesting. > > >>Here's a variation on Vlad's circuit: > > >>https://dl.dropbox.com/u/53724080/SED/Stretcher.JPG > > >--- > >You've still got the initial gate delay from input to output, > > That's pretty much unavoidable. I doubt that it matters to George. > > =A0and the > > >prop delay through the buffers isn't exactly precise... > > How do you know that? I didn't specify the parts, other than max PD. They=could> be implemented as a tapped delay line, passive or silicon. Or one could t=rim Vcc> to tweak prop delay. There are lots of possibilities. > > Post something better. > > -- > > John Larkin =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Highland Technology Incwww=.highlandtechnology.com=A0 jlarkin at highlandtechnology dot com> > Precision electronic instrumentation > Picosecond-resolution Digital Delay and Pulse generators > Custom timing and laser controllers > Photonics and fiberoptic TTL data links > VME =A0analog, thermocouple, LVDT, synchro, tachometer > Multichannel arbitrary waveform generators- Hide quoted text - > > - Show quoted text -In this case I'm timing a pulse stream. But absolute time doesn't matter as much as relative time. So as long as the prop. delay doesn't stop more than one pulse from traveling down the signal chain, then it may not matter. George H.
