On Fri, 08 Mar 2013 15:08:02 -0600, John Fields <jfields@austininstruments.com> wrote:>On Fri, 08 Mar 2013 09:46:41 -0800, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Fri, 08 Mar 2013 11:08:42 -0600, John Fields >><jfields@austininstruments.com> wrote: >> >>>On Fri, 08 Mar 2013 06:54:50 -0800, John Larkin >>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Fri, 08 Mar 2013 01:18:53 -0600, John Fields <jfields@austininstruments.com> >>>>wrote: >>>> >>>>>On Thu, 07 Mar 2013 16:02:49 -0800, John Larkin >>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>>http://www.highlandtechnology.com/DSS/T240DS.shtml >>>>> >>>>>--- >>>>>That's not a pulse stretcher, cheater, that's a pulse _generator_. >>>> >>>>It's a one-shot. It has no internal trigger. It generates no pulses. >>> >>>--- >>>Geez, and here I always thought that one-shots generated waveforms >>>with more-or-less crispy edges with a more-or less constant voltage >>>level between them. >>> >>>You know, what we here in the real world call a "pulse". >>> >>>Take a look at the first bulleted item on your data sheet and you'll >>>see that you do too, you fucking loon... >> >>More uninformed whining. > >--- >Hey, you're the one with a data sheet touting your widget as a pulse >generator, and I'm agreeing with it, so what's your problem? >--- > >>All you want to do is argue about words, because you can't design electronics. > >--- >All you want to do is argue, about anything, in the vain hope that >some miracle will come around when you've made a mistake - and it's >been pointed out to you - and bail you out of the ocean of shit you >get yourself into with that silly macho facade of infallibility. > >As for the "design" part, we've both seen my posting history, so we >both know you're just having a hissie fit. >--- > >>You don't like any of my pulse stretchers, so design a better one. > >--- >In your own words, they're not pulse stretchers, they're: > >"single-channel externally-triggered complementary-output pulse >generator"(s). > >and, having had no experience with them, I neither like them nor >dislike them. > >I would like to see some more data, though; Zout, maximum trigger >rate, stuff like that... >--- > >>Post it here. > >--- >Sorry Charlie; too much work for too little return. > >Especially when all you're looking for is something - anything - you >can mouth off against and start another harangue to keep you in the >limelight. >--- > >>Your great love Jim can do the same. > >--- >Over the years, after a rocky beginning, I've come to appreciate Jim >as a friend, a colleague, and a very clever circuit designer, and what >love I have for him is fraternal.Well, the feeling doesn't seem to be mutual; he's dissing you lately. I suppose his goal is to be universally disliked. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Simple pulse stretcher
Started by ●March 7, 2013
Reply by ●March 8, 20132013-03-08
Reply by ●March 8, 20132013-03-08
On Fri, 08 Mar 2013 14:55:50 -0600, Vladimir Vassilevsky <nospam@nowhere.com> wrote:>On 3/7/2013 2:36 PM, George Herold wrote: >> On Mar 7, 3:12 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >>> On 3/7/2013 12:21 PM, 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.) >>> > >>> Something like this: >>> >>> http://www.abvolt.com/misc/pulse_stretch.jpg >>> >>> You got the idea. >>> >> Yeah I was thinking of something like that too. The diode thing was >> an easy 'hack' and seems to be working just fine. (I stuck in 10k >> and 10pF and have about a 50ns minimum pulse.) Life is good. > >Fie. Analog parts on the digital board. > >http://www.abvolt.com/misc/pulse_stretch_2.jpg > >This should satisfy most captious critics. > >VLVThe low input flushes the delay chain. Cute. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Reply by ●March 8, 20132013-03-08
On Fri, 08 Mar 2013 13:24:35 -0800, John Larkin <jlarkin@highlandtechnology.com> wrote:>On Fri, 08 Mar 2013 15:08:02 -0600, John Fields ><jfields@austininstruments.com> wrote: > >>On Fri, 08 Mar 2013 09:46:41 -0800, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >>>On Fri, 08 Mar 2013 11:08:42 -0600, John Fields >>><jfields@austininstruments.com> wrote: >>> >>>>On Fri, 08 Mar 2013 06:54:50 -0800, John Larkin >>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>> >>>>>On Fri, 08 Mar 2013 01:18:53 -0600, John Fields <jfields@austininstruments.com> >>>>>wrote: >>>>> >>>>>>On Thu, 07 Mar 2013 16:02:49 -0800, John Larkin >>>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>>> >>>>>>>http://www.highlandtechnology.com/DSS/T240DS.shtml >>>>>> >>>>>>--- >>>>>>That's not a pulse stretcher, cheater, that's a pulse _generator_. >>>>> >>>>>It's a one-shot. It has no internal trigger. It generates no pulses. >>>> >>>>--- >>>>Geez, and here I always thought that one-shots generated waveforms >>>>with more-or-less crispy edges with a more-or less constant voltage >>>>level between them. >>>> >>>>You know, what we here in the real world call a "pulse". >>>> >>>>Take a look at the first bulleted item on your data sheet and you'll >>>>see that you do too, you fucking loon... >>> >>>More uninformed whining. >> >>--- >>Hey, you're the one with a data sheet touting your widget as a pulse >>generator, and I'm agreeing with it, so what's your problem? >>--- >> >>>All you want to do is argue about words, because you can't design electronics. >> >>--- >>All you want to do is argue, about anything, in the vain hope that >>some miracle will come around when you've made a mistake - and it's >>been pointed out to you - and bail you out of the ocean of shit you >>get yourself into with that silly macho facade of infallibility. >> >>As for the "design" part, we've both seen my posting history, so we >>both know you're just having a hissie fit. >>--- >> >>>You don't like any of my pulse stretchers, so design a better one. >> >>--- >>In your own words, they're not pulse stretchers, they're: >> >>"single-channel externally-triggered complementary-output pulse >>generator"(s). >> >>and, having had no experience with them, I neither like them nor >>dislike them. >> >>I would like to see some more data, though; Zout, maximum trigger >>rate, stuff like that... >>--- >> >>>Post it here. >> >>--- >>Sorry Charlie; too much work for too little return. >> >>Especially when all you're looking for is something - anything - you >>can mouth off against and start another harangue to keep you in the >>limelight. >>--- >> >>>Your great love Jim can do the same. >> >>--- >>Over the years, after a rocky beginning, I've come to appreciate Jim >>as a friend, a colleague, and a very clever circuit designer, and what >>love I have for him is fraternal. > >Well, the feeling doesn't seem to be mutual; he's dissing you lately.--- You think? My take on it is that he's criticizing me for interacting with assholes like you who very rarely have anything good to say and am, therefore, wasting bandwidth. He's right, kinda, But you still need your comeuppance. --->I suppose his goal is to be universally disliked.--- Well, since you're not the universe and he has clients who fall outside of your sphere of influence, I suspect your wish for him to be universally disliked won't be fulfilled. More to the point, however, why would you want him to be universally disliked? -- JF
Reply by ●March 8, 20132013-03-08
On Mar 8, 3:55=A0pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote:> On 3/7/2013 2:36 PM, George Herold wrote: > > > > > > > > > > > On Mar 7, 3:12 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: > >> On 3/7/2013 12:21 PM, George Herold 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.) > > >> Something like this: > > >>http://www.abvolt.com/misc/pulse_stretch.jpg > > >> You got the idea. > > > Yeah I was thinking of something like that too. =A0The diode thing was > > an easy 'hack' =A0and seems to be working just fine. =A0(I stuck in 10k > > and 10pF and have about a 50ns minimum pulse.) =A0Life is good. > > Fie. Analog parts on the digital board. > > http://www.abvolt.com/misc/pulse_stretch_2.jpg > > This should satisfy most captious critics. > > VLVThat's pretty, but if the part's fast it might not meet George's min. output pulse needs. An R-C or two would fix that. <ducks> -- Cheers, James Arthur
Reply by ●March 8, 20132013-03-08
On Mar 8, 9:38=A0am, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat> wrote:> On Fri, 8 Mar 2013 05:45:37 -0800 (PST), George Herold > > <gher...@teachspin.com> wrote: > >On Mar 8, 12:44=A0am, bloggs.fredbloggs.f...@gmail.com wrote: > >> On Thursday, March 7, 2013 11:14:01 PM UTC-5, Vladimir Vassilevsky wro=te:> >> > truth? Take a good scope, pulse generator and see for yourself. > > >> Okay, you know what you measured, but you need to be real careful with=layout using that parts family. It used to be a point of advantage for a l= ogic family that it was unresponsive to full logic level transitions of dur= ation less than the fastest edge rates in the system. Interwiring capacitiv= e coupling into a nice high impedance input converts the transition into a = nice square pulse there. I think Lenin covered that one.> > >Hi Fred, As Vlad said the HC series was really doing just fine with > >10ns pulses and perhaps only 'missing' 1% =A0of the 5 or 6 ns ones. =A0I > > The tinylogic one-shot that John mentioned is guaranteed to trigger > off 2.5ns pulses (with a 5V 'Vcc'). Available in a nice friendly > 0.65mm pitch 8-pin package (also a 0.5mm pitch or 1 x 2mm BGA if you > are in need of pain).Sweet, I think a nice one shot is the right medicine. It looks like I'll stretch it out to ~200ns, not a big deal with 1us bins, the first time bin is ~20% 'short'. We'll document it in the manual and specs, 70% of our users will never notice. Hey, we should use the 200ns pulse as the monitor output! maybe they'll notice if it's on the 'scope. I'm not sure why I didn't have a one-shot in to begin with. (there's been some 'vibe' that one shots are bad.(?) It all seems so obvious in retrospect. George H.
Reply by ●March 8, 20132013-03-08
On Fri, 8 Mar 2013 17:26:12 -0800 (PST), dagmargoodboat@yahoo.com wrote:>On Mar 8, 3:55�pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >> On 3/7/2013 2:36 PM, George Herold wrote: >> >> >> >> >> >> >> >> >> >> > On Mar 7, 3:12 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >> >> On 3/7/2013 12:21 PM, 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.) >> >> >> Something like this: >> >> >>http://www.abvolt.com/misc/pulse_stretch.jpg >> >> >> You got the idea. >> >> > Yeah I was thinking of something like that too. �The diode thing was >> > an easy 'hack' �and seems to be working just fine. �(I stuck in 10k >> > and 10pF and have about a 50ns minimum pulse.) �Life is good. >> >> Fie. Analog parts on the digital board. >> >> http://www.abvolt.com/misc/pulse_stretch_2.jpg >> >> This should satisfy most captious critics. >> >> VLV > >That's pretty, but if the part's fast it might not meet George's min. >output pulse needs. An R-C or two would fix that. > ><ducks>It's so crappy, it's almost Larkinesque. The f...ing "specification" was to widen a 5ns sliver. A 5ns sliver won't even produce a sigh out of 74HC stuff. ...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 8, 20132013-03-08
On Fri, 08 Mar 2013 15:56:16 -0600, John Fields <jfields@austininstruments.com> wrote:>On Fri, 08 Mar 2013 13:24:35 -0800, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Fri, 08 Mar 2013 15:08:02 -0600, John Fields >><jfields@austininstruments.com> wrote: >> >>>On Fri, 08 Mar 2013 09:46:41 -0800, John Larkin >>><jlarkin@highlandtechnology.com> wrote: >>> >>>>On Fri, 08 Mar 2013 11:08:42 -0600, John Fields >>>><jfields@austininstruments.com> wrote: >>>> >>>>>On Fri, 08 Mar 2013 06:54:50 -0800, John Larkin >>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>>On Fri, 08 Mar 2013 01:18:53 -0600, John Fields <jfields@austininstruments.com> >>>>>>wrote: >>>>>> >>>>>>>On Thu, 07 Mar 2013 16:02:49 -0800, John Larkin >>>>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>>>> >>>>>>>>http://www.highlandtechnology.com/DSS/T240DS.shtml >>>>>>> >>>>>>>--- >>>>>>>That's not a pulse stretcher, cheater, that's a pulse _generator_. >>>>>> >>>>>>It's a one-shot. It has no internal trigger. It generates no pulses. >>>>> >>>>>--- >>>>>Geez, and here I always thought that one-shots generated waveforms >>>>>with more-or-less crispy edges with a more-or less constant voltage >>>>>level between them. >>>>> >>>>>You know, what we here in the real world call a "pulse". >>>>> >>>>>Take a look at the first bulleted item on your data sheet and you'll >>>>>see that you do too, you fucking loon... >>>> >>>>More uninformed whining. >>> >>>--- >>>Hey, you're the one with a data sheet touting your widget as a pulse >>>generator, and I'm agreeing with it, so what's your problem? >>>--- >>> >>>>All you want to do is argue about words, because you can't design electronics. >>> >>>--- >>>All you want to do is argue, about anything, in the vain hope that >>>some miracle will come around when you've made a mistake - and it's >>>been pointed out to you - and bail you out of the ocean of shit you >>>get yourself into with that silly macho facade of infallibility. >>> >>>As for the "design" part, we've both seen my posting history, so we >>>both know you're just having a hissie fit. >>>--- >>> >>>>You don't like any of my pulse stretchers, so design a better one. >>> >>>--- >>>In your own words, they're not pulse stretchers, they're: >>> >>>"single-channel externally-triggered complementary-output pulse >>>generator"(s). >>> >>>and, having had no experience with them, I neither like them nor >>>dislike them. >>> >>>I would like to see some more data, though; Zout, maximum trigger >>>rate, stuff like that... >>>--- >>> >>>>Post it here. >>> >>>--- >>>Sorry Charlie; too much work for too little return. >>> >>>Especially when all you're looking for is something - anything - you >>>can mouth off against and start another harangue to keep you in the >>>limelight. >>>--- >>> >>>>Your great love Jim can do the same. >>> >>>--- >>>Over the years, after a rocky beginning, I've come to appreciate Jim >>>as a friend, a colleague, and a very clever circuit designer, and what >>>love I have for him is fraternal. >> >>Well, the feeling doesn't seem to be mutual; he's dissing you lately. > >--- >You think? > >My take on it is that he's criticizing me for interacting with >assholes like you who very rarely have anything good to say and am, >therefore, wasting bandwidth. > >He's right, kinda, > >But you still need your comeuppance.Design something. That's how things are counted here. -- 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 8, 20132013-03-08
On Fri, 08 Mar 2013 19:00:33 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Fri, 8 Mar 2013 17:26:12 -0800 (PST), dagmargoodboat@yahoo.com >wrote: > >>On Mar 8, 3:55�pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >>> On 3/7/2013 2:36 PM, George Herold wrote: >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> > On Mar 7, 3:12 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >>> >> On 3/7/2013 12:21 PM, 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.) >>> >>> >> Something like this: >>> >>> >>http://www.abvolt.com/misc/pulse_stretch.jpg >>> >>> >> You got the idea. >>> >>> > Yeah I was thinking of something like that too. �The diode thing was >>> > an easy 'hack' �and seems to be working just fine. �(I stuck in 10k >>> > and 10pF and have about a 50ns minimum pulse.) �Life is good. >>> >>> Fie. Analog parts on the digital board. >>> >>> http://www.abvolt.com/misc/pulse_stretch_2.jpg >>> >>> This should satisfy most captious critics. >>> >>> VLV >> >>That's pretty, but if the part's fast it might not meet George's min. >>output pulse needs. An R-C or two would fix that. >> >><ducks> > >It's so crappy, it's almost Larkinesque. The f...ing "specification" >was to widen a 5ns sliver. A 5ns sliver won't even produce a sigh out >of 74HC stuff. > > ...Jim ThompsonSo design something. Do you remember how? -- 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 8, 20132013-03-08
John Larkin wrote:> On Fri, 08 Mar 2013 19:00:33 -0700, Jim Thompson > <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > > >>On Fri, 8 Mar 2013 17:26:12 -0800 (PST), dagmargoodboat@yahoo.com >>wrote: >> >> >>>On Mar 8, 3:55 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >>> >>>>On 3/7/2013 2:36 PM, George Herold wrote: >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>>>On Mar 7, 3:12 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >>>>> >>>>>>On 3/7/2013 12:21 PM, 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.) >>>> >>>>>>Something like this: >>>> >>>>>>http://www.abvolt.com/misc/pulse_stretch.jpg >>>> >>>>>>You got the idea. >>>> >>>>>Yeah I was thinking of something like that too. The diode thing was >>>>>an easy 'hack' and seems to be working just fine. (I stuck in 10k >>>>>and 10pF and have about a 50ns minimum pulse.) Life is good. >>>> >>>>Fie. Analog parts on the digital board. >>>> >>>>http://www.abvolt.com/misc/pulse_stretch_2.jpg >>>> >>>>This should satisfy most captious critics. >>>> >>>>VLV >>> >>>That's pretty, but if the part's fast it might not meet George's min. >>>output pulse needs. An R-C or two would fix that. >>> >>><ducks> >> >>It's so crappy, it's almost Larkinesque. The f...ing "specification" >>was to widen a 5ns sliver. A 5ns sliver won't even produce a sigh out >>of 74HC stuff. >> >> ...Jim Thompson > > > > So design something. Do you remember how? > >:) Jamie
Reply by ●March 8, 20132013-03-08
On Mar 9, 3:54=A0am, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:> On Fri, 08 Mar 2013 01:18:53 -0600, John Fields <jfie...@austininstrument=s.com>> wrote: > > >On Thu, 07 Mar 2013 16:02:49 -0800, John Larkin > ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: > > >>http://www.highlandtechnology.com/DSS/T240DS.shtml > > >--- > >That's not a pulse stretcher, cheater, that's a pulse _generator_. > > It's a one-shot. It has no internal trigger. It generates no pulses. > > And neither you nor Jim have a clue as to how this might be done. > > We have a customer who wants us to take this down to 10 ps pulses. At tha=t> point, I'm not sure that I know how that might be done. We're thinking ab=out it. http://books.google.co.nz/books?id=3D-pi4vP6xMOQC&pg=3DPA571&lpg=3DPA571&dq= =3D%22emitter-coupled%22+monostable&source=3Dbl&ots=3DCFsGlVE2YN&sig=3DTUbj= QhyQPk_cd5tj_UKlIhFVXt8&hl=3Den&sa=3DX&ei=3DTZw6UYmmPMeNyAHA4oHYAg&ved=3D0C= EIQ6AEwAw#v=3Donepage&q=3D%22emitter-coupled%22%20monostable&f=3Dfalse describes the emitter-coupled monostable. Put one together out of a pair of wide-band tansistors - BFR92 or better - with 33R up against each base, and you can cetainly get below 10nsec. Since the mechanism depends on the change of base-emitter impedance with emitter current, it isn't as easy as it might be to get a wide range of output pulse widths. Jim Thompson could probably remember a better solution for you. The long-obsolete MC10198 ECL monostable http://www.digchip.com/datasheets/parts/datasheet/343/MC10198-pdf.php could just get down to 10nsec, but we used two of them when we wanted to offer long pulses as well - being able to switch in bigger capacitors put too much stray capacitance on the relevant input pin for 10nsec operation. Something boringly obvious with a constant current ramp and a fast comparator would do the job, but - as with the MC10198, being able to switch in bigger capacitors to generate much longer pulses is probably incompatible with a 10nsec pulse width. -- Bill Sloman, Sydney
