On Wednesday, June 26, 2013 12:39:43 PM UTC-4, Joerg wrote: Clamping makes no sense for logic families designed to operate off a wide r= ange of power supplies and able to withstand being mixed up with logic oper= ating off different supplies. Your thinking is very 1970ish. Nothing wrong = with the architecture, it is used in some extremely fast logic families, it= has been perfected IOW. Finally, the modern gate oxide process does not bl= ow a hole instantaneously when the voltage stress exceeds some threshold by= one microvolt. It is a graded breakdown that requires time.
8051F020 series, 5V tolerant input schematic?
Started by ●June 25, 2013
Reply by ●June 26, 20132013-06-26
Reply by ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>><jlarkin@highlandtechnology.com> wrote: >>> >>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>wrote: >>>> >>>>>Jim Thompson wrote: >>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> Jim Thompson wrote: >>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Jim Thompson wrote: >>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Jim Thompson wrote: >>>>> >>>>>[...] >>>>> >>>>> >>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>> >>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>> >>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>> about model quality... did no good.) >>>>>>>>>> >>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>> >>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>> is the de facto winner, oh well. >>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>> >>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>> efficient method. >>>>>>> >>>>>>> >>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>> >>>>>>> Me, too. >>>>>>> >>>>>>> >>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>> board? You're screwed. >>>>>>>> >>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>> then that gets simulated separately. >>>>>>> >>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>> the early 90's. >>>>>>> >>>>>>> >>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>> customer. Enjoy >:-} >>>>>>>> >>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>> made my choice, and that choice is LTC. >>>>>> >>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>> >>>>> >>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>one who had to discover that the hard way. >>>>> >>>>> >>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>> have passed, no solution. >>>>>> >>>>> >>>>>In my case the LTC design engineers looked at it right away, found out >>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>and corrected things. That left a very positive impression with me. >>>>> >>>>>Over the years I experienced numerous similar situations with other, >>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>> >>>>> >>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>> "LTspice, love it or leave it" :-( >>>>>> >>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>> behavioral internally. >>>>>> >>>>> >>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>sure beats non-behavioral sims that take hours. >>>> >>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>of sim to model my product, so I'd get two or three runs per week. And >>>>I'd run out of hard drive for the RAW file! >>>> >>>>I've ordered samples. >>> >>>Look thru the HELP for "alternate solver"... some types of parts >>>require a different matrix parsing. >>> >>> ...Jim Thompson >> >>If I improved it 20:1 it would still be too slow to give me useful >>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>files from milliseconds of sim time. >> >>And I don't entirely trust the simulation; sometimes it does weird >>double or staggered gate drive pulses that don't make obvious sense. >> >>Besides, it's fun to solder stuff now and then. > >Some of those LT parts are known by those of us "versed in the art" to >have _real_ bugs. > > ...Jim ThompsonYou seem to be mainly versed in yourself. Maybe JF will write a poem in your honor. -- 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 ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 13:05:59 -0700, John Larkin <jlarkin@highlandtechnology.com> wrote:>On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >>>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>>><jlarkin@highlandtechnology.com> wrote: >>>> >>>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>>wrote: >>>>> >>>>>>Jim Thompson wrote: >>>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>>> wrote: >>>>>>> >>>>>>>> Jim Thompson wrote: >>>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> Jim Thompson wrote: >>>>>> >>>>>>[...] >>>>>> >>>>>> >>>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>>> >>>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>>> >>>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>>> about model quality... did no good.) >>>>>>>>>>> >>>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>>> >>>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>>> is the de facto winner, oh well. >>>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>>> >>>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>>> efficient method. >>>>>>>> >>>>>>>> >>>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>>> >>>>>>>> Me, too. >>>>>>>> >>>>>>>> >>>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>>> board? You're screwed. >>>>>>>>> >>>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>>> then that gets simulated separately. >>>>>>>> >>>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>>> the early 90's. >>>>>>>> >>>>>>>> >>>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>>> customer. Enjoy >:-} >>>>>>>>> >>>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>>> made my choice, and that choice is LTC. >>>>>>> >>>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>>> >>>>>> >>>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>>one who had to discover that the hard way. >>>>>> >>>>>> >>>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>>> have passed, no solution. >>>>>>> >>>>>> >>>>>>In my case the LTC design engineers looked at it right away, found out >>>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>>and corrected things. That left a very positive impression with me. >>>>>> >>>>>>Over the years I experienced numerous similar situations with other, >>>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>>> >>>>>> >>>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>>> "LTspice, love it or leave it" :-( >>>>>>> >>>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>>> behavioral internally. >>>>>>> >>>>>> >>>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>>sure beats non-behavioral sims that take hours. >>>>> >>>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>>of sim to model my product, so I'd get two or three runs per week. And >>>>>I'd run out of hard drive for the RAW file! >>>>> >>>>>I've ordered samples. >>>> >>>>Look thru the HELP for "alternate solver"... some types of parts >>>>require a different matrix parsing. >>>> >>>> ...Jim Thompson >>> >>>If I improved it 20:1 it would still be too slow to give me useful >>>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>>files from milliseconds of sim time. >>> >>>And I don't entirely trust the simulation; sometimes it does weird >>>double or staggered gate drive pulses that don't make obvious sense. >>> >>>Besides, it's fun to solder stuff now and then. >> >>Some of those LT parts are known by those of us "versed in the art" to >>have _real_ bugs. >> >> ...Jim Thompson > >You seem to be mainly versed in yourself. Maybe JF will write a poem >in your honor.Please do me the honor of keeping your mouth shut. I have no interest in your opinions. I can confirm as fact an LT part that simulates nicely, but fails on the PCB, confounding the FAE, and, now, the factory. NOLA white trash. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 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 ●June 26, 20132013-06-26
John Larkin wrote:> On Wed, 26 Jun 2013 11:51:19 -0700, Joerg <invalid@invalid.invalid> > wrote: > >> John Larkin wrote: >>> On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>> wrote: >>> >>>> Jim Thompson wrote: >>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>> wrote: >>>>> >>>>>> Jim Thompson wrote: >>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>> wrote: >>>>>>> >>>>>>>> Jim Thompson wrote: >>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Jim Thompson wrote: >>>> [...] >>>> >>>> >>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>> >>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>> >>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>> about model quality... did no good.) >>>>>>>>> >>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>> >>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>> is the de facto winner, oh well. >>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>> >>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>> efficient method. >>>>>> >>>>>> >>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>> Me, too. >>>>>> >>>>>> >>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>> board? You're screwed. >>>>>>> >>>>>> On high end designs I never do that, and there is no need to. You can >>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>> then that gets simulated separately. >>>>>> >>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>> time. For example, my first mass-produced device with a boost converter >>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>> the early 90's. >>>>>> >>>>>> >>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>> customer. Enjoy >:-} >>>>>>> >>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>> made my choice, and that choice is LTC. >>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>> >>>> Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>> one who had to discover that the hard way. >>>> >>>> >>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>> have passed, no solution. >>>>> >>>> In my case the LTC design engineers looked at it right away, found out >>>> that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>> and corrected things. That left a very positive impression with me. >>>> >>>> Over the years I experienced numerous similar situations with other, >>>> larger manufacturers. The classic solution was an attempt to cover it up. >>>> >>>> >>>>> I posted the problem on the LTspice list, but was basically told, >>>>> "LTspice, love it or leave it" :-( >>>>> >>>>> All I've been able to find out is that LTspice encrypted models are >>>>> behavioral internally. >>>>> >>>> They are, mostly. That is the reason why you can simulate switchers so >>>> blazingly fast. This does come with pitfalls and (minor) risks but it >>>> sure beats non-behavioral sims that take hours. >>> My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>> of sim to model my product, so I'd get two or three runs per week. And >>> I'd run out of hard drive for the RAW file! >>> >> If it's not super secret send it over and I'll take a look. There's >> usually a way to speed things up, like by pre-charging a large cap and >> things like that. > > > No secret, here it is. But C1 needs to be 4000 uF in real life, and I > want to see how it ramps up and stabilizes, and how it recovers after > a big load pulse. I'm making 10G RAW files in milliseconds of sim > time, and I need seconds. > > But if you know of any tweaks that would speed it up, I'd appreciate > that. >I don't see much of a point in doing that. The switcher can deliver a certain amount of energy per cycle, mainly set per R5 and V2. So for long term sims you could just assume a current source that's curbed when the regulated output voltage is reached. If you absolutely have to simulate with 4000uF you could set the inductor coupling to k=1 which helps a little, then play with abstol and reltol. But it'll still take forever. 4000uF is huge. Like modeling rear axle shock response for one complete Sahara desert crossing. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●June 26, 20132013-06-26
bloggs.fredbloggs.fred@gmail.com wrote:> On Wednesday, June 26, 2013 12:39:43 PM UTC-4, Joerg wrote: > > > Clamping makes no sense for logic families designed to operate off a > wide range of power supplies and able to withstand being mixed up > with logic operating off different supplies. Your thinking is very > 1970ish. Nothing wrong with the architecture, it is used in some > extremely fast logic families, it has been perfected IOW. Finally, > the modern gate oxide process does not blow a hole instantaneously > when the voltage stress exceeds some threshold by one microvolt. It > is a graded breakdown that requires time.The last sentence sums it up what is missing: How many volts above abs max are allowed over how many milliseconds or microseconds? There use to be family specs and stuff like that but not anymore. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 13:09:52 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Wed, 26 Jun 2013 13:05:59 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin >>><jlarkin@highlandtechnology.com> wrote: >>> >>>>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>>>><jlarkin@highlandtechnology.com> wrote: >>>>> >>>>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>>>wrote: >>>>>> >>>>>>>Jim Thompson wrote: >>>>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Jim Thompson wrote: >>>>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>>> Jim Thompson wrote: >>>>>>> >>>>>>>[...] >>>>>>> >>>>>>> >>>>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>>>> >>>>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>>>> >>>>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>>>> about model quality... did no good.) >>>>>>>>>>>> >>>>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>>>> >>>>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>>>> is the de facto winner, oh well. >>>>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>>>> >>>>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>>>> efficient method. >>>>>>>>> >>>>>>>>> >>>>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>>>> >>>>>>>>> Me, too. >>>>>>>>> >>>>>>>>> >>>>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>>>> board? You're screwed. >>>>>>>>>> >>>>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>>>> then that gets simulated separately. >>>>>>>>> >>>>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>>>> the early 90's. >>>>>>>>> >>>>>>>>> >>>>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>>>> customer. Enjoy >:-} >>>>>>>>>> >>>>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>>>> made my choice, and that choice is LTC. >>>>>>>> >>>>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>>>> >>>>>>> >>>>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>>>one who had to discover that the hard way. >>>>>>> >>>>>>> >>>>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>>>> have passed, no solution. >>>>>>>> >>>>>>> >>>>>>>In my case the LTC design engineers looked at it right away, found out >>>>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>>>and corrected things. That left a very positive impression with me. >>>>>>> >>>>>>>Over the years I experienced numerous similar situations with other, >>>>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>>>> >>>>>>> >>>>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>>>> "LTspice, love it or leave it" :-( >>>>>>>> >>>>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>>>> behavioral internally. >>>>>>>> >>>>>>> >>>>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>>>sure beats non-behavioral sims that take hours. >>>>>> >>>>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>>>of sim to model my product, so I'd get two or three runs per week. And >>>>>>I'd run out of hard drive for the RAW file! >>>>>> >>>>>>I've ordered samples. >>>>> >>>>>Look thru the HELP for "alternate solver"... some types of parts >>>>>require a different matrix parsing. >>>>> >>>>> ...Jim Thompson >>>> >>>>If I improved it 20:1 it would still be too slow to give me useful >>>>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>>>files from milliseconds of sim time. >>>> >>>>And I don't entirely trust the simulation; sometimes it does weird >>>>double or staggered gate drive pulses that don't make obvious sense. >>>> >>>>Besides, it's fun to solder stuff now and then. >>> >>>Some of those LT parts are known by those of us "versed in the art" to >>>have _real_ bugs. >>> >>> ...Jim Thompson >> >>You seem to be mainly versed in yourself. Maybe JF will write a poem >>in your honor. > >Please do me the honor of keeping your mouth shut. I have no interest >in your opinions.Honor? Among Thompsons?> >I can confirm as fact an LT part that simulates nicely, but fails on >the PCB, confounding the FAE, and, now, the factory.Likely a bad PCB design. Did you do it? -- 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 ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 13:15:21 -0700, Joerg <invalid@invalid.invalid> wrote:>John Larkin wrote: >> On Wed, 26 Jun 2013 11:51:19 -0700, Joerg <invalid@invalid.invalid> >> wrote: >> >>> John Larkin wrote: >>>> On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>> wrote: >>>> >>>>> Jim Thompson wrote: >>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> Jim Thompson wrote: >>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Jim Thompson wrote: >>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Jim Thompson wrote: >>>>> [...] >>>>> >>>>> >>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>> >>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>> >>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>> about model quality... did no good.) >>>>>>>>>> >>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>> >>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>> is the de facto winner, oh well. >>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>> >>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>> efficient method. >>>>>>> >>>>>>> >>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>> Me, too. >>>>>>> >>>>>>> >>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>> board? You're screwed. >>>>>>>> >>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>> then that gets simulated separately. >>>>>>> >>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>> the early 90's. >>>>>>> >>>>>>> >>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>> customer. Enjoy >:-} >>>>>>>> >>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>> made my choice, and that choice is LTC. >>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>> >>>>> Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>> one who had to discover that the hard way. >>>>> >>>>> >>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>> have passed, no solution. >>>>>> >>>>> In my case the LTC design engineers looked at it right away, found out >>>>> that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>> and corrected things. That left a very positive impression with me. >>>>> >>>>> Over the years I experienced numerous similar situations with other, >>>>> larger manufacturers. The classic solution was an attempt to cover it up. >>>>> >>>>> >>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>> "LTspice, love it or leave it" :-( >>>>>> >>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>> behavioral internally. >>>>>> >>>>> They are, mostly. That is the reason why you can simulate switchers so >>>>> blazingly fast. This does come with pitfalls and (minor) risks but it >>>>> sure beats non-behavioral sims that take hours. >>>> My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>> of sim to model my product, so I'd get two or three runs per week. And >>>> I'd run out of hard drive for the RAW file! >>>> >>> If it's not super secret send it over and I'll take a look. There's >>> usually a way to speed things up, like by pre-charging a large cap and >>> things like that. >> >> >> No secret, here it is. But C1 needs to be 4000 uF in real life, and I >> want to see how it ramps up and stabilizes, and how it recovers after >> a big load pulse. I'm making 10G RAW files in milliseconds of sim >> time, and I need seconds. >> >> But if you know of any tweaks that would speed it up, I'd appreciate >> that. >> > >I don't see much of a point in doing that. The switcher can deliver a >certain amount of energy per cycle, mainly set per R5 and V2. So for >long term sims you could just assume a current source that's curbed when > the regulated output voltage is reached.With all the cap load that I can stand to sim, it actually bursts. That is probably good in my application. It does run at about 300 KHz, which isn't what I expected, given the timing resistor. Maybe, with the inductor I have, it's skipping clocks waiting for the current to build up to the peak trip point. OK, go ahead, force me to buy a smaller, cheaper inductor.> >If you absolutely have to simulate with 4000uF you could set the >inductor coupling to k=1 which helps a little, then play with abstol and >reltol. But it'll still take forever. 4000uF is huge. Like modeling rear >axle shock response for one complete Sahara desert crossing.Mantis and Metcal next! -- 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 ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 14:31:11 -0700, John Larkin <jlarkin@highlandtechnology.com> wrote:>On Wed, 26 Jun 2013 13:09:52 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Wed, 26 Jun 2013 13:05:59 -0700, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >>>On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin >>>><jlarkin@highlandtechnology.com> wrote: >>>> >>>>>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >>>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>> >>>>>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>>>>><jlarkin@highlandtechnology.com> wrote: >>>>>> >>>>>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>>>>wrote: >>>>>>> >>>>>>>>Jim Thompson wrote: >>>>>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>>>> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> Jim Thompson wrote: >>>>>>>> >>>>>>>>[...] >>>>>>>> >>>>>>>> >>>>>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>>>>> >>>>>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>>>>> about model quality... did no good.) >>>>>>>>>>>>> >>>>>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>>>>> >>>>>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>>>>> is the de facto winner, oh well. >>>>>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>>>>> >>>>>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>>>>> efficient method. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>>>>> >>>>>>>>>> Me, too. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>>>>> board? You're screwed. >>>>>>>>>>> >>>>>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>>>>> then that gets simulated separately. >>>>>>>>>> >>>>>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>>>>> the early 90's. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>>>>> customer. Enjoy >:-} >>>>>>>>>>> >>>>>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>>>>> made my choice, and that choice is LTC. >>>>>>>>> >>>>>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>>>>> >>>>>>>> >>>>>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>>>>one who had to discover that the hard way. >>>>>>>> >>>>>>>> >>>>>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>>>>> have passed, no solution. >>>>>>>>> >>>>>>>> >>>>>>>>In my case the LTC design engineers looked at it right away, found out >>>>>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>>>>and corrected things. That left a very positive impression with me. >>>>>>>> >>>>>>>>Over the years I experienced numerous similar situations with other, >>>>>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>>>>> >>>>>>>> >>>>>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>>>>> "LTspice, love it or leave it" :-( >>>>>>>>> >>>>>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>>>>> behavioral internally. >>>>>>>>> >>>>>>>> >>>>>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>>>>sure beats non-behavioral sims that take hours. >>>>>>> >>>>>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>>>>of sim to model my product, so I'd get two or three runs per week. And >>>>>>>I'd run out of hard drive for the RAW file! >>>>>>> >>>>>>>I've ordered samples. >>>>>> >>>>>>Look thru the HELP for "alternate solver"... some types of parts >>>>>>require a different matrix parsing. >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>>If I improved it 20:1 it would still be too slow to give me useful >>>>>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>>>>files from milliseconds of sim time. >>>>> >>>>>And I don't entirely trust the simulation; sometimes it does weird >>>>>double or staggered gate drive pulses that don't make obvious sense. >>>>> >>>>>Besides, it's fun to solder stuff now and then. >>>> >>>>Some of those LT parts are known by those of us "versed in the art" to >>>>have _real_ bugs. >>>> >>>> ...Jim Thompson >>> >>>You seem to be mainly versed in yourself. Maybe JF will write a poem >>>in your honor.--- There's no need to, since Jim's doing all right. But Wow, that poetry thing really has you wired up, huh? It's something that you're not good at, which casts aspersions on you, and which you can't refute using your crude complaints. --->>Please do me the honor of keeping your mouth shut. I have no interest >>in your opinions. > >Honor? Among Thompsons?--- Since you've decided to cast aspersions, why not apprise us about the superiority of your family tree? --->>I can confirm as fact an LT part that simulates nicely, but fails on >>the PCB, confounding the FAE, and, now, the factory. > >Likely a bad PCB design. Did you do it?--- With the factory befuddled, It's not likely that your input is important. -- JF
Reply by ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 18:46:54 -0500, John Fields <jfields@austininstruments.com> wrote:>On Wed, 26 Jun 2013 14:31:11 -0700, John Larkin ><jlarkin@highlandtechnology.com> wrote: > >>On Wed, 26 Jun 2013 13:09:52 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Wed, 26 Jun 2013 13:05:59 -0700, John Larkin >>><jlarkin@highlandtechnology.com> wrote: >>> >>>>On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin >>>>><jlarkin@highlandtechnology.com> wrote: >>>>> >>>>>>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >>>>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>>> >>>>>>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>>>>>><jlarkin@highlandtechnology.com> wrote: >>>>>>> >>>>>>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>wrote: >>>>>>>> >>>>>>>>>Jim Thompson wrote: >>>>>>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>>>>> wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>>> Jim Thompson wrote: >>>>>>>>> >>>>>>>>>[...] >>>>>>>>> >>>>>>>>> >>>>>>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>>>>>> >>>>>>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>>>>>> about model quality... did no good.) >>>>>>>>>>>>>> >>>>>>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>>>>>> >>>>>>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>>>>>> is the de facto winner, oh well. >>>>>>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>>>>>> >>>>>>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>>>>>> efficient method. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>>>>>> >>>>>>>>>>> Me, too. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>>>>>> board? You're screwed. >>>>>>>>>>>> >>>>>>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>>>>>> then that gets simulated separately. >>>>>>>>>>> >>>>>>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>>>>>> the early 90's. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>>>>>> customer. Enjoy >:-} >>>>>>>>>>>> >>>>>>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>>>>>> made my choice, and that choice is LTC. >>>>>>>>>> >>>>>>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>>>>>> >>>>>>>>> >>>>>>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>>>>>one who had to discover that the hard way. >>>>>>>>> >>>>>>>>> >>>>>>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>>>>>> have passed, no solution. >>>>>>>>>> >>>>>>>>> >>>>>>>>>In my case the LTC design engineers looked at it right away, found out >>>>>>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>>>>>and corrected things. That left a very positive impression with me. >>>>>>>>> >>>>>>>>>Over the years I experienced numerous similar situations with other, >>>>>>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>>>>>> >>>>>>>>> >>>>>>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>>>>>> "LTspice, love it or leave it" :-( >>>>>>>>>> >>>>>>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>>>>>> behavioral internally. >>>>>>>>>> >>>>>>>>> >>>>>>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>>>>>sure beats non-behavioral sims that take hours. >>>>>>>> >>>>>>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>>>>>of sim to model my product, so I'd get two or three runs per week. And >>>>>>>>I'd run out of hard drive for the RAW file! >>>>>>>> >>>>>>>>I've ordered samples. >>>>>>> >>>>>>>Look thru the HELP for "alternate solver"... some types of parts >>>>>>>require a different matrix parsing. >>>>>>> >>>>>>> ...Jim Thompson >>>>>> >>>>>>If I improved it 20:1 it would still be too slow to give me useful >>>>>>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>>>>>files from milliseconds of sim time. >>>>>> >>>>>>And I don't entirely trust the simulation; sometimes it does weird >>>>>>double or staggered gate drive pulses that don't make obvious sense. >>>>>> >>>>>>Besides, it's fun to solder stuff now and then. >>>>> >>>>>Some of those LT parts are known by those of us "versed in the art" to >>>>>have _real_ bugs. >>>>> >>>>> ...Jim Thompson >>>> >>>>You seem to be mainly versed in yourself. Maybe JF will write a poem >>>>in your honor. > >--- >There's no need to, since Jim's doing all right. > >But Wow, that poetry thing really has you wired up, huh? > >It's something that you're not good at, which casts aspersions on you, >and which you can't refute using your crude complaints. >--- > >>>Please do me the honor of keeping your mouth shut. I have no interest >>>in your opinions. >> >>Honor? Among Thompsons? > >--- >Since you've decided to cast aspersions, why not apprise us about the >superiority of your family tree?Nice, hard-working, innocuous people, mostly. JT has bragged about what a vengeful, unforgiving lot the Thompsons are, himself included. Hey, I believe him.>--- > >>>I can confirm as fact an LT part that simulates nicely, but fails on >>>the PCB, confounding the FAE, and, now, the factory. >> >>Likely a bad PCB design. Did you do it? > >--- >With the factory befuddled, It's not likely that your input is >important.He could actually provide some on-topic content once in a while. Like what part it is and what the problem is. Hell, you could provide some on-topic content once in a while, instead of just whining about personalities. -- 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 ●June 26, 20132013-06-26
On Wed, 26 Jun 2013 14:31:11 -0700, John Larkin <jlarkin@highlandtechnology.com> wrote:>On Wed, 26 Jun 2013 13:09:52 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Wed, 26 Jun 2013 13:05:59 -0700, John Larkin >><jlarkin@highlandtechnology.com> wrote: >> >>>On Wed, 26 Jun 2013 12:33:06 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Wed, 26 Jun 2013 11:57:42 -0700, John Larkin >>>><jlarkin@highlandtechnology.com> wrote: >>>> >>>>>On Wed, 26 Jun 2013 11:47:04 -0700, Jim Thompson >>>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>> >>>>>>On Wed, 26 Jun 2013 11:34:14 -0700, John Larkin >>>>>><jlarkin@highlandtechnology.com> wrote: >>>>>> >>>>>>>On Wed, 26 Jun 2013 10:54:54 -0700, Joerg <invalid@invalid.invalid> >>>>>>>wrote: >>>>>>> >>>>>>>>Jim Thompson wrote: >>>>>>>>> On Wed, 26 Jun 2013 10:04:19 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>> On Wed, 26 Jun 2013 09:26:58 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> Jim Thompson wrote: >>>>>>>>>>>>> On Wed, 26 Jun 2013 09:08:52 -0700, Joerg <invalid@invalid.invalid> >>>>>>>>>>>>> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> Jim Thompson wrote: >>>>>>>> >>>>>>>>[...] >>>>>>>> >>>>>>>> >>>>>>>>>>>>>>> And Analog Devices modeling efforts are now managed by a MARKETING VP, >>>>>>>>>>>>>>> and they are ultimately heading to requiring simulation of their parts >>>>>>>>>>>>>>> ONLY on their web-based simulator. >>>>>>>>>>>>>>> >>>>>>>>>>>>>> That would be a marketing decision that borders on stupid. >>>>>>>>>>>>> I was there (San Jose) last August trying to convince them of the best >>>>>>>>>>>>> way to do modeling... let me see the real netlist and then I'd match >>>>>>>>>>>>> it behaviorally. The MARKETING VP nixed the idea. >>>>>>>>>>>>> >>>>>>>>>>>>> (I even showed them various posts from this newsgroup complaining >>>>>>>>>>>>> about model quality... did no good.) >>>>>>>>>>>>> >>>>>>>>>>>> Then I assume they'll never understand why, when it comes to performance >>>>>>>>>>>> and cost is not a major issue, I always default to LTC and never even >>>>>>>>>>>> look at AD unless I can't find a chip at LTC. This is because LTC has >>>>>>>>>>>> behavioral models that work in LTSpice and AD does not. >>>>>>>>>>>> >>>>>>>>>>>> Same with TI. Who in their right mind would install and learn half a >>>>>>>>>>>> dozen competing "free" simulators? If they can't understand that LTSpice >>>>>>>>>>>> is the de facto winner, oh well. >>>>>>>>>>> PSpice will run ANY non-encrypted model, as will LTspice, HSpice, any >>>>>>>>>>> Cadence tool, and most amateur spin-offs. >>>>>>>>>>> >>>>>>>>>> If you run a complicated switcher non-behavioral (and I had to do that) >>>>>>>>>> the sims take forever. For designing SMPS that clearly is not the most >>>>>>>>>> efficient method. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Encrypting so a model will run only on the parent tool turns me off. >>>>>>>>>> >>>>>>>>>> Me, too. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> What do you do if you want to mix LT and ADI and TI parts on your >>>>>>>>>>> board? You're screwed. >>>>>>>>>>> >>>>>>>>>> On high end designs I never do that, and there is no need to. You can >>>>>>>>>> usually get everything at LTC. Except for some hardcore RF stuff and >>>>>>>>>> then that gets simulated separately. >>>>>>>>>> >>>>>>>>>> If it has to be cheap then no special ICs are used anyhow most of the >>>>>>>>>> time. For example, my first mass-produced device with a boost converter >>>>>>>>>> revolves around a CD40106 as the "highest-tech" chip. There is no >>>>>>>>>> dedicated PWM chip because that would have added at least 10c back in >>>>>>>>>> the early 90's. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>> Joerg, sounds like LT is happy as a clam with you. You're a locked-in >>>>>>>>>>> customer. Enjoy >:-} >>>>>>>>>>> >>>>>>>>>> Well, yeah, at some point you have to pick one and run with that. I have >>>>>>>>>> made my choice, and that choice is LTC. >>>>>>>>> >>>>>>>>> "Most" of their stuff is good. I've had a recent situation where an >>>>>>>>> encrypted model works just fine on LTspice, but not on a PCB. >>>>>>>>> >>>>>>>> >>>>>>>>Same here, the LT6700 had a glitch on the chip and I was the unfortunate >>>>>>>>one who had to discover that the hard way. >>>>>>>> >>>>>>>> >>>>>>>>> The FAE was flummoxed, referred the problem to factory... 4 months >>>>>>>>> have passed, no solution. >>>>>>>>> >>>>>>>> >>>>>>>>In my case the LTC design engineers looked at it right away, found out >>>>>>>>that it was indeed a bug, fessed up, apologized, rolled up the sleeves >>>>>>>>and corrected things. That left a very positive impression with me. >>>>>>>> >>>>>>>>Over the years I experienced numerous similar situations with other, >>>>>>>>larger manufacturers. The classic solution was an attempt to cover it up. >>>>>>>> >>>>>>>> >>>>>>>>> I posted the problem on the LTspice list, but was basically told, >>>>>>>>> "LTspice, love it or leave it" :-( >>>>>>>>> >>>>>>>>> All I've been able to find out is that LTspice encrypted models are >>>>>>>>> behavioral internally. >>>>>>>>> >>>>>>>> >>>>>>>>They are, mostly. That is the reason why you can simulate switchers so >>>>>>>>blazingly fast. This does come with pitfalls and (minor) risks but it >>>>>>>>sure beats non-behavioral sims that take hours. >>>>>>> >>>>>>>My LT3757 boost sim runs at about 15 PPM of real time. I need seconds >>>>>>>of sim to model my product, so I'd get two or three runs per week. And >>>>>>>I'd run out of hard drive for the RAW file! >>>>>>> >>>>>>>I've ordered samples. >>>>>> >>>>>>Look thru the HELP for "alternate solver"... some types of parts >>>>>>require a different matrix parsing. >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>>If I improved it 20:1 it would still be too slow to give me useful >>>>>feedback, and I'd still run out of hard drive. I was getting 10G RAW >>>>>files from milliseconds of sim time. >>>>> >>>>>And I don't entirely trust the simulation; sometimes it does weird >>>>>double or staggered gate drive pulses that don't make obvious sense. >>>>> >>>>>Besides, it's fun to solder stuff now and then. >>>> >>>>Some of those LT parts are known by those of us "versed in the art" to >>>>have _real_ bugs. >>>> >>>> ...Jim Thompson >>> >>>You seem to be mainly versed in yourself. Maybe JF will write a poem >>>in your honor. >> >>Please do me the honor of keeping your mouth shut. I have no interest >>in your opinions. > >Honor? Among Thompsons? > >> >>I can confirm as fact an LT part that simulates nicely, but fails on >>the PCB, confounding the FAE, and, now, the factory. > >Likely a bad PCB design. Did you do it?Learn to read... your comprehension is REALLY BAD... "confounding the FAE, and, now, the factory" ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 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.
