On 01/02/2017 19:36, JM wrote:> On 01/02/2017 19:20, Jim Thompson wrote: >> On Wed, 01 Feb 2017 19:14:17 +0000, JM <dontreplytothis173@gmail.com> >> wrote: >> >>>> On Wed, 01 Feb 2017 10:06:33 -0700, Jim Thompson >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >> [snip] >>>>> >>>>> Here is a first-pass model without a whole lot of data... >>>>> >>>>> <http://www.analog-innovations.com/DeviceModelsSubckts/D1N4148_FO_RRSpice_Model_2017-02-01_10-01-02.png> >>>>> >>>>> >>>>> for various rise/fall times... >>>>> >>>>> ** Analysis setup ** >>>>> .tran 200ns 200ns 0 10ps >>>>> .STEP PARAM TRF LIST >>>>> + 100ps 1ns 10ns 20ns 50ns >>>>> >>>>> ...Jim Thompson >> [snip] >>>> >>> >>> There have been a lot of Spice diode models which account for charge >>> storage developed. Most if not all of them concentrate on PIN diodes >>> but I'm sure the same modeling techniques would apply to non PIN diodes. >>> Search in the IEEE journals related to power electronics if you're >>> interested (an example is http://ieeexplore.ieee.org/document/349750/). >> >> Papers aren't _my_ problem... I have several dozen on the subject. I >> have developed a fairly simple modeling method that seems robust. All >> I need is data from specific devices to test my method. >> >> ...Jim Thompson >> > > Here's some data courtesy of Bob Pease > https://www.dropbox.com/s/6s0o7j2rx59k5i8/pease.pdf?dl=0Which isn't of much use - just shows turn on.
Spice Diode Modeling of Forward Overshoot & Reverse Recovery
Started by ●January 30, 2017
Reply by ●February 1, 20172017-02-01
Reply by ●February 1, 20172017-02-01
On Wed, 01 Feb 2017 12:27:10 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Wed, 01 Feb 2017 11:15:27 -0800, John Larkin ><jjlarkinxyxy@highlandtechnology.com> wrote: > >>On Wed, 01 Feb 2017 12:07:04 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >[snip] >>>>>> >>>>>>That's not a model, it's a screenshot of some waveforms. As usual. >>>>> >>>>>You and Phil need to grow up and cut the crap... I'm not going to >>>>>divulge what's in the model... unless you want to pay for a model >:-} >>>>>I'll post an encrypted model as soon as I figure out how to get a DOS >>>>>prompt in Win7 !@#$%^&* >>>>> >>>>> ...Jim Thompson >>>> >>>>If you're not going to share what you know, all you are doing is >>>>bragging about how smart you are, with no proof. >>> >>>How do we know if _your_ scope photos weren't rigged ?>:-} >> >>Because I am known to share stuff like this. > >You shared photos, I shared screenshots. What's the difference?I shared all the info I had, and you are hiding and encripting what you claim to know. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●February 1, 20172017-02-01
On Wed, 01 Feb 2017 14:45:07 -0800, John Larkin <jjlarkinxyxy@highlandtechnology.com> wrote:>On Wed, 01 Feb 2017 12:27:10 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Wed, 01 Feb 2017 11:15:27 -0800, John Larkin >><jjlarkinxyxy@highlandtechnology.com> wrote: >> >>>On Wed, 01 Feb 2017 12:07:04 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>[snip] >>>>>>> >>>>>>>That's not a model, it's a screenshot of some waveforms. As usual. >>>>>> >>>>>>You and Phil need to grow up and cut the crap... I'm not going to >>>>>>divulge what's in the model... unless you want to pay for a model >:-} >>>>>>I'll post an encrypted model as soon as I figure out how to get a DOS >>>>>>prompt in Win7 !@#$%^&* >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>>If you're not going to share what you know, all you are doing is >>>>>bragging about how smart you are, with no proof. >>>> >>>>How do we know if _your_ scope photos weren't rigged ?>:-} >>> >>>Because I am known to share stuff like this. >> >>You shared photos, I shared screenshots. What's the difference? > >I shared all the info I had, and you are hiding and encripting what >you claim to know.I never claim anything I'm not sure of. And you're a horse's ass >:-} ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions.
Reply by ●February 1, 20172017-02-01
On Wed, 01 Feb 2017 15:54:11 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Wed, 01 Feb 2017 14:45:07 -0800, John Larkin ><jjlarkinxyxy@highlandtechnology.com> wrote: > >>On Wed, 01 Feb 2017 12:27:10 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Wed, 01 Feb 2017 11:15:27 -0800, John Larkin >>><jjlarkinxyxy@highlandtechnology.com> wrote: >>> >>>>On Wed, 01 Feb 2017 12:07:04 -0700, Jim Thompson >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>[snip] >>>>>>>> >>>>>>>>That's not a model, it's a screenshot of some waveforms. As usual. >>>>>>> >>>>>>>You and Phil need to grow up and cut the crap... I'm not going to >>>>>>>divulge what's in the model... unless you want to pay for a model >:-} >>>>>>>I'll post an encrypted model as soon as I figure out how to get a DOS >>>>>>>prompt in Win7 !@#$%^&* >>>>>>> >>>>>>> ...Jim Thompson >>>>>> >>>>>>If you're not going to share what you know, all you are doing is >>>>>>bragging about how smart you are, with no proof. >>>>> >>>>>How do we know if _your_ scope photos weren't rigged ?>:-} >>>> >>>>Because I am known to share stuff like this. >>> >>>You shared photos, I shared screenshots. What's the difference? >> >>I shared all the info I had, and you are hiding and encripting what >>you claim to know. > >I never claim anything I'm not sure of. And you're a horse's ass >:-} > > ...Jim ThompsonWell, helping you sure turns out to be a stupid thing to do. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●February 3, 20172017-02-03
On 02/01/2017 01:28 PM, Jim Thompson wrote:> On Wed, 01 Feb 2017 09:48:54 -0800, John Larkin > <jjlarkin@highlandtechnology.com> wrote: > >> On Wed, 01 Feb 2017 10:06:33 -0700, Jim Thompson >> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>> On Mon, 30 Jan 2017 17:33:05 -0800, John Larkin >>> <jjlarkinxyxy@highlandtechnology.com> wrote: >>> >>>> On Mon, 30 Jan 2017 17:37:44 -0700, Jim Thompson >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>> Nothing like a PhD telling me something can't be done to get my solver >>>>> genes working double-time... >>>>> >>>>> Over baby-back ribs at Firebirds this afternoon I realized how to >>>>> parameterize my method. >>>>> >>>>> But all the information I have is from "peer-reviewed" semi-BS IEEE >>>>> papers. >>>>> >>>>> Would someone be so kind as to take data on something common like a >>>>> 1N914... forward overshoot and reverse recovery at various slew rates >>>>> and current levels? >>>>> >>>>> Then I can fit a known object. >>>>> >>>>> Thanks! >>>>> >>>>> ...Jim Thompson >>>> >>>> I posted this previously: >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Diode_TurnOn/1N914_a.JPG >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Diode_TurnOn/1N914_b.JPG >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Diode_TurnOn/1N914_c.JPG >>>> >>>> https://dl.dropboxusercontent.com/u/53724080/Diode_TurnOn/1N914_d.JPG >>>> >>>> >>>> That's a 1N914 from the middle of a 50-ohm transmission line to >>>> ground. You can see the pulse drive level on the P400 display; that's >>>> the unloaded generator output voltage... divide by 2 for the 50 ohm >>>> load. >>>> >>>> The diode is effectively driven by 25 ohms. >>>> >>>> Generator rise time is about 1 ns. >>>> >>>> In that last pic, you can see the diode holding up the falling edge of >>>> the pulse for a couple of ns until it runs out of stored charge. >>>> >>>> I wouldn't expect various "1N914" parts to be super similar. >>> >>> Here is a first-pass model without a whole lot of data... >>> >>> <http://www.analog-innovations.com/DeviceModelsSubckts/D1N4148_FO_RRSpice_Model_2017-02-01_10-01-02.png> >>> >>> for various rise/fall times... >>> >>> ** Analysis setup ** >>> .tran 200ns 200ns 0 10ps >>> .STEP PARAM TRF LIST >>> + 100ps 1ns 10ns 20ns 50ns >>> >>> ...Jim Thompson >> >> >> That's not a model, it's a screenshot of some waveforms. As usual. > > You and Phil need to grow up and cut the crap... I'm not going to > divulge what's in the model... unless you want to pay for a model >:-} > I'll post an encrypted model as soon as I figure out how to get a DOS > prompt in Win7 !@#$%^&* > > ...Jim Thompson >We aren't the ones doing the bragging at the moment, though, and an encrypted model wouldn't prove anything, any more than the silly screen shots do. If your IP is that valuable, why take it to your grave? And if money is your real reason for not posting the model, you have your business plan all wrong. I published a major fraction of everything I know about technology in a book that has been the foundation of my consulting business. If you were to write the H&H of modelling, you wouldn't have to be looking for work, believe me. Folks would be better able to do the routine jobs in house, but they'd send you the interesting ones. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●February 3, 20172017-02-03
Phil Hobbs wrote...> > On 02/01/2017 01:28 PM, Jim Thompson wrote: >> >> You and Phil need to grow up and cut the crap... >> I'm not going to divulge what's in the model... >> unless you want to pay for a model >:-} > > If you were to write the H&H of modelling, you > wouldn't have to be looking for work, believe me. > Folks would be better able to do the routine > jobs in house, but they'd send you the > interesting ones.I agree. And anyway, Jim makes his $$ and most enjoys designing ICs. Nobody will be able to match his skills at that, simply because he might teach people how to model better. And as you say, giving away secrets increases business. Jim is getting along in years, and he should start creating a serious legacy. -- Thanks, - Win
Reply by ●February 3, 20172017-02-03
On Fri, 3 Feb 2017 09:26:03 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>On 02/01/2017 01:28 PM, Jim Thompson wrote: >> On Wed, 01 Feb 2017 09:48:54 -0800, John Larkin >> <jjlarkin@highlandtechnology.com> wrote:[snip]>>> >>> That's not a model, it's a screenshot of some waveforms. As usual. >> >> You and Phil need to grow up and cut the crap... I'm not going to >> divulge what's in the model... unless you want to pay for a model >:-} >> I'll post an encrypted model as soon as I figure out how to get a DOS >> prompt in Win7 !@#$%^&* >> >> ...Jim Thompson >> > >We aren't the ones doing the bragging at the moment, though, and an >encrypted model wouldn't prove anything, any more than the silly screen >shots do. >[snip] Running the encrypted model in LTspice and seeing the results wouldn't prove anything ?? ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions.
Reply by ●February 3, 20172017-02-03
On 02/03/2017 10:09 AM, Jim Thompson wrote:> On Fri, 3 Feb 2017 09:26:03 -0500, Phil Hobbs > <pcdhSpamMeSenseless@electrooptical.net> wrote: > >> On 02/01/2017 01:28 PM, Jim Thompson wrote: >>> On Wed, 01 Feb 2017 09:48:54 -0800, John Larkin >>> <jjlarkin@highlandtechnology.com> wrote: > > [snip] >>>> >>>> That's not a model, it's a screenshot of some waveforms. As >>>> usual. >>> >>> You and Phil need to grow up and cut the crap... I'm not going to >>> divulge what's in the model... unless you want to pay for a model >>> >:-} I'll post an encrypted model as soon as I figure out how to >>> get a DOS prompt in Win7 !@#$%^&* ...Jim Thompson >>> >> >> We aren't the ones doing the bragging at the moment, though, and >> an encrypted model wouldn't prove anything, any more than the >> silly screen shots do. >> > [snip] > > Running the encrypted model in LTspice and seeing the results > wouldn't prove anything ??No, it wouldn't. Let me refresh your memory of what I actually wrote in the "is there something wrong with PMOS" thread (with snippage restored):> On 01/29/2017 10:59 AM, Jim Thompson wrote: >> On Sun, 29 Jan 2017 04:43:37 -0800 (PST), pcdhobbs@gmail.com >> wrote: >>>>>> >>>>>> There's generally nothing wrong with Spice... whatever the >>>>>> flavor... IF the model is good.>>>>>>>>> There are two issues, I think. The first is (as you say) that the mfg >>>>> needs to make good models if possible. >>>>> >>>>> The second is more of a SPICE limitation: the D() facility doesn't >>>>> include diffusion delays, which makes it intrinsically incapable of >>>>> accounting for V_F overshoot, and the MESFET facility doesn't model >>>>> real device behaviour such as the aforementioned self-biasing of >>>>> pHEMTs. >>>>> >>>>> The one is a modelling issue, but the second is an intrinsic >>>>> limitation of the simulator. >>>>> >>>>> This is not to say that it can't be patched up, just that after N >>>>> years we're still waiting. (Other more expensive tools may be better, >>>>> of course.)>>>>> The second is more of a SPICE limitation: the D() facility >>>>> doesn't >>>> include diffusion delays, which makes it intrinsically >>>> incapable of accounting for V_F overshoot, and the MESFET >>>> facility doesn't model real device behaviour such as the >>>> aforementioned self-biasing of pHEMTs. >>> >>>> (1) Nonsense. It's quite feasible to write such a MODEL. >>> >>> I've asked about SPICE modelling the forward overshoot of diodes >>> both here and in the Yahoo LTspice group, and heard in both >>> places that the SPICE D() facility is too stupid to model it. If >>> you can produce a model for a 1N4148 that overshoots to 1.4 V or >>> so on turn-on (about par for a real unit), and exhibits the same >>> variation with dI/dt as a real one, I'll happily concede your >>> point. >>> >>> It won't be using just D(), though, that's for sure. >> >> You're evading my point. I said it is possible to write a proper >> model. It just hasn't been done (properly) yet, though I've >> developed a model that's pretty close, it's not _perfect_... I >> strive for perfection so I'm still playing with it as time permits > > I'm not evading your point, I'm disagreeing with it. I claim that > no such model exists, and you appear to agree. Your faith in SPICE > is touching but provably wrong--it can't model everything without > hacking the simulator code, not merely the models. > > For something whose behaviour is fairly simple and which has wide > device-to-device variations, such as a diode with diffusion > overshoot, you can probably cruft together some subcircuit model > that gets vaguely into the ballpark, maybe using the transmission > line model to account for time delays. > > It sure won't be just D() with parameters, though.Which you eventually agreed with, and apparently have built such a model for the simple step-excitation case. I can't use it for anything because I don't use glass-package 1N914s any more except in crufty breadboards, and can't adjust it to fit other diodes. And since it doesn't model actual diffusion behaviour, I have no reason to suppose that it would work in more complicated and realistic situations such as tone bursts in wideband noise. If it were human-readable, I'd certainly read it, and might learn something. But it isn't, which makes it entirely uninteresting.> >> >>> >>>>> >>>> The one is a modelling issue, but the second is an intrinsic >>>> limitation of the simulator. >>> >>> (2) Nonsense. Refer to (1) above. >>> >>> SPICE is a pretty capable solver for largish sparse systems of >>> nonlinear OD >> >> Yes. Pretty much as long as you can write an equation for it Spice >> can solve it. >> >> ...Jim Thompson >> > > No. Not transport equations, as I said, and there are lots of other > examples of integral or integrodifferential equations. They're > generally not reducible to systems of ODEs, because no ODE can be > nonlocal, and so no solver limited to ODEs can handle them. > > You can't even write an ODE to describe a piece of coax from a > circuits point of view--the SPICE transmission line isn't an ODE > model, it's a special case, i.e. the simulator code has to be hacked > up to support it. > > Cheers > > Phil HobbsYou see here that what I'm disagreeing with is your blanket statement, "Pretty much as long as you can write an equation for it Spice can solve it." Which is provably false, as I said (and then proved). Hacking together a subcircuit model that produces a similar curve is not solving the actual 1-D transport equation. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●February 3, 20172017-02-03
On Fri, 3 Feb 2017 11:08:57 -0500, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: [snip]> >Hacking together a subcircuit model that produces a similar curve is not >solving the actual 1-D transport equation. > >Cheers > >Phil HobbsSorry. It's behavior is that of diffusion. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions.
Reply by ●February 3, 20172017-02-03
