On Thu, 20 Jul 2017 15:02:16 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Thu, 20 Jul 2017 14:56:32 -0700, Joerg <news@analogconsultants.com> >wrote: > >>On 2017-07-20 14:38, Jim Thompson wrote: >>> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin >>> <jjlarkin@highland_snip_technology.com> wrote: >>> >>>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin >>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>> >>>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson >>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>>> >>>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin >>>>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I'm simulating a flyback switcher and noticed that any K < 1 in the >>>>>>>> transformer radically slows down the sim, which is annoyingly slow >>>>>>>> already... 90 seconds to sim 60 ms of startup and a little pulsed load >>>>>>>> blip. Maybe 6:1 slower with a little leakage inductance. So I only >>>>>>>> include leakage inductance to tweak the snubber. >>>>>>> >>>>>>> You have to use Mikey's idealized components... fast, but... >>>>>>> >>>>>>> ...Jim Thompson >>>>>> >>>>>> Using a discrete inductor to simulate the leakage inductance is no >>>>>> faster. Nice try, JL. >>>>> >>>>> What happened to LTspice's "fastest simulator ever" ?>:-} >>>>> >>>>> ...Jim Thompson >>>> >>>> I have no idea how fast this would run in some other simulator, or if >>>> the leakage L would matter as much. But since I'm using an LTC3803, >>>> probably no other software would work. >>> >>> That's the problem with LT, and Analog Devices and sometime TI... if >>> your model will run on only your proprietary simulator, what the f**k >>> good is it? >>> >> >>The beauty is that there _is_ a model and it usually is a good >>compromise between "real" and behavioral simulation. With other mfgs you >>eitehr get no model at all or one that has no behavioral parts and where >>you can have an extensive dinner in town and the sim still won't be past 5%. >> >>I am certain that LTSpice has brought LTC more profits than any of their >>marketing efforts. >> >>[...] > >Suppose that LT parts are only a percentage of those parts in my >system, and there are parts from AD and TI, models of which won't run >on LTspice? Now what? I think it's a universally DUMB marketing >strategy.It's TI's fault if LT Spice won't run their models. ADI will be transitioning to LT Spice, I've heard. Maybe that's why they bought LT.> >If I was in the jelly-bean-user business I wouldn't buy any part whose >model wasn't Berkeley-Spice-compliant. > > ...Jim ThompsonI buy lots of parts that have no models, or that I don't care to simulate. I can read data sheets, and breadboard a part if I think it's necessary. You can't fully trust the models anyhow. I use UniversalOpamp2 a lot, in LT Spice, to sim other parts. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
LT spice, leakage inductance
Started by ●July 20, 2017
Reply by ●July 20, 20172017-07-20
Reply by ●July 20, 20172017-07-20
On Thu, 20 Jul 2017 15:40:10 -0700, John Larkin <jjlarkin@highland_snip_technology.com> wrote:>On Thu, 20 Jul 2017 15:02:16 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >[snip]>>Suppose that LT parts are only a percentage of those parts in my >>system, and there are parts from AD and TI, models of which won't run >>on LTspice? Now what? I think it's a universally DUMB marketing >>strategy. > >It's TI's fault if LT Spice won't run their models. > >ADI will be transitioning to LT Spice, I've heard. Maybe that's why >they bought LT.We'll see. AD has their own proprietary simulator, ADICE. My expectation is that LTspice will continue to exist, but you'll have to simulate AD parts in THEIR cloud.> >> >>If I was in the jelly-bean-user business I wouldn't buy any part whose >>model wasn't Berkeley-Spice-compliant. >> >> ...Jim Thompson > >I buy lots of parts that have no models, or that I don't care to >simulate. I can read data sheets, and breadboard a part if I think >it's necessary. You can't fully trust the models anyhow. > >I use UniversalOpamp2 a lot, in LT Spice, to sim other parts.You're just so wonderful >:-} Actually I think you're nothing but a contrarian. ...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 | I'm looking for work... see my website. Thinking outside the box...producing elegant & economic solutions.
Reply by ●July 20, 20172017-07-20
On 2017-07-20 15:36, Jim Thompson wrote:> On Thu, 20 Jul 2017 15:30:20 -0700, Joerg <news@analogconsultants.com> > wrote: > >> On 2017-07-20 15:02, Jim Thompson wrote: > > [snip] > >>> >>> Suppose that LT parts are only a percentage of those parts in my >>> system, and there are parts from AD and TI, models of which won't run >>> on LTspice? Now what? I think it's a universally DUMB marketing >>> strategy. >>> >> >> Au contraire. When cost isn't critical but R&D time is of the essence I >> always default to LTC parts. Just like everyone around me does. Mission >> accomplished, I'd say. >> >> >>> If I was in the jelly-bean-user business I wouldn't buy any part whose >>> model wasn't Berkeley-Spice-compliant. >>> >> >> If you work in super-jelly-bean mode you will. Because the 10c switcher >> chip from Asia will only come with a skimpy datasheet and there is no >> model at all but it costs less than the 18c domestic IC. > > Duh! What happened with your "mission accomplished"? You bought a > cheapy rip-off instead ?;-) >Huh? What I meant is that you have to do many jelly-bean design completely sans simulator. Because there are neither SPICE nor LTSpice models. If, as you said, you won't consider parts without a Berkeley SPICE model you cannot play in that kind of game. It's simply not possible. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 20, 20172017-07-20
On 2017-07-20 15:32, John Larkin wrote:> On Thu, 20 Jul 2017 14:38:33 -0700, Jim Thompson > <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin >> <jjlarkin@highland_snip_technology.com> wrote: >> >>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson >>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin >>>> <jjlarkin@highland_snip_technology.com> wrote: >>>> >>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson >>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>> >>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin >>>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>>> >>>>>>> >>>>>>> >>>>>>> I'm simulating a flyback switcher and noticed that any K < 1 in the >>>>>>> transformer radically slows down the sim, which is annoyingly slow >>>>>>> already... 90 seconds to sim 60 ms of startup and a little pulsed load >>>>>>> blip. Maybe 6:1 slower with a little leakage inductance. So I only >>>>>>> include leakage inductance to tweak the snubber. >>>>>> >>>>>> You have to use Mikey's idealized components... fast, but... >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>> Using a discrete inductor to simulate the leakage inductance is no >>>>> faster. Nice try, JL. >>>> >>>> What happened to LTspice's "fastest simulator ever" ?>:-} >>>> >>>> ...Jim Thompson >>> >>> I have no idea how fast this would run in some other simulator, or if >>> the leakage L would matter as much. But since I'm using an LTC3803, >>> probably no other software would work. >> >> That's the problem with LT, and Analog Devices and sometime TI... if >> your model will run on only your proprietary simulator, what the f**k >> good is it? > > It sells a lot of parts. LT Spice is great, and free. It works with > non-LT parts, too! >Sure does. I designed a few complete TDRs where only one fast comparator was from LTC and the rest all discrete. All RF part models ran immediately. LTSpice can take in regular SPICE models. Since I don't have a 20GHz sampling scope the simulator was the only way to get that job done, couldn't do it on the bench. Works great and is in production now. In hindsight the whole design process took less time that it likely would have on the bench. Unfortunately is was also less healthy because one sits all day long. One of the reasons why I now have a mountain bike. [...] -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 20, 20172017-07-20
On Thu, 20 Jul 2017 15:59:18 -0700, Joerg <news@analogconsultants.com> wrote: [snip]> >What I meant is that you have to do many jelly-bean design completely >sans simulator. Because there are neither SPICE nor LTSpice models. If, >as you said, you won't consider parts without a Berkeley SPICE model you >cannot play in that kind of game. It's simply not possible.OK. I understand. After all I have over 15 years of design experience (and almost all of my standard products, and patents) under my belt without aid of any simulator... just paper and breadboard. I think I first got on a VAX780 sometime around 1980, got my first personal 386/387 and copy of PSpice around 1987. I tend, now, to roll my own models for those parts the customer wants to use (I/O to/from my chip design) from their datasheets so that I can at least come close to a full system simulation. My models will run on LTspice since a number of my customers want to "play along" and verify my PSpice results. (Device level circuits, such as my chip designs, run just fine on LTspice... you just paste-in, for example... .LIB "C:\PSpice\DeviceLib\CD4007\CD4007_RIT.lib" and away you go.) ...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 | I'm looking for work... see my website. Thinking outside the box...producing elegant & economic solutions.
Reply by ●July 20, 20172017-07-20
"Joerg" <news@analogconsultants.com> wrote in message news:etcpbjFi5iuU2@mid.individual.net...> A lot of times all one needs to know is how far a certain circuitry is > from the point of going unstable. There it doesn't really matter.High Q (RF) circuits are notoriously bad at that. Sure, there are better approaches to nonlinear RF, but none cheaper than SPICE. My concern comes mainly when I want to know current consumption and power dissipation accurately. Most of the power is burned on the edges, so the edges need to be known precisely, to have the subtraction in the efficiency calculation come out accurate. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
Reply by ●July 21, 20172017-07-21
On Friday, 21 July 2017 00:30:15 UTC+2, Joerg wrote:> On 2017-07-20 15:02, Jim Thompson wrote: > > On Thu, 20 Jul 2017 14:56:32 -0700, Joerg <news@analogconsultants.com> > > wrote: > > > >> On 2017-07-20 14:38, Jim Thompson wrote: > >>> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin > >>> <jjlarkin@highland_snip_technology.com> wrote: > >>> > >>>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson > >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>>> > >>>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin > >>>>> <jjlarkin@highland_snip_technology.com> wrote: > >>>>> > >>>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson > >>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>>>>> > >>>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin > >>>>>>> <jjlarkin@highland_snip_technology.com> wrote: > >>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> I'm simulating a flyback switcher and noticed that any K < 1 in the > >>>>>>>> transformer radically slows down the sim, which is annoyingly slow > >>>>>>>> already... 90 seconds to sim 60 ms of startup and a little pulsed load > >>>>>>>> blip. Maybe 6:1 slower with a little leakage inductance. So I only > >>>>>>>> include leakage inductance to tweak the snubber. > >>>>>>> > >>>>>>> You have to use Mikey's idealized components... fast, but... > >>>>>>> > >>>>>>> ...Jim Thompson > >>>>>> > >>>>>> Using a discrete inductor to simulate the leakage inductance is no > >>>>>> faster. Nice try, JL. > >>>>> > >>>>> What happened to LTspice's "fastest simulator ever" ?>:-} > >>>>> > >>>>> ...Jim Thompson > >>>> > >>>> I have no idea how fast this would run in some other simulator, or if > >>>> the leakage L would matter as much. But since I'm using an LTC3803, > >>>> probably no other software would work. > >>> > >>> That's the problem with LT, and Analog Devices and sometime TI... if > >>> your model will run on only your proprietary simulator, what the f**k > >>> good is it? > >>> > >> > >> The beauty is that there _is_ a model and it usually is a good > >> compromise between "real" and behavioral simulation. With other mfgs you > >> eitehr get no model at all or one that has no behavioral parts and where > >> you can have an extensive dinner in town and the sim still won't be past 5%. > >> > >> I am certain that LTSpice has brought LTC more profits than any of their > >> marketing efforts. > >> > >> [...] > > > > Suppose that LT parts are only a percentage of those parts in my > > system, and there are parts from AD and TI, models of which won't run > > on LTspice? Now what? I think it's a universally DUMB marketing > > strategy. > > > > Au contraire. When cost isn't critical but R&D time is of the essence I > always default to LTC parts. Just like everyone around me does. Mission > accomplished, I'd say. > > > > If I was in the jelly-bean-user business I wouldn't buy any part whose > > model wasn't Berkeley-Spice-compliant. > > > > If you work in super-jelly-bean mode you will. Because the 10c switcher > chip from Asia will only come with a skimpy datasheet and there is no > model at all but it costs less than the 18c domestic IC. >I have never used a LT part, the costs are simply too high, doing almost only high volume products Just for fun, needing an analog mux, searching Digikey came up with 2.5USD for the cheapest LT (LTC222), and the cheapest comparable product was the good old 74HC4066D, at a price of 9 US cents (almost 30 times cheaper) Just try to search for the cheapest LT opamp: https://www.digikey.com/products/en/integrated-circuits-ics/linear-amplifiers-instrumentation-op-amps-buffer-amps/687?FV=ffe002af%2Cfffc00a1&mnonly=0&ColumnSort=1000011&page=1&stock=0&pbfree=0&rohs=0&cad=0&datasheet=0&nstock=0&photo=0&nonrohs=0&newproducts=0&k=opamp&quantity=&ptm=0&fid=0&pageSize=25&pkeyword=opamp That is really some sort of advanced marketing joke Again, the cheapest LT is 10 times more expensive than the cheapest alternative Don't we have an obbligation to select the best part and not let it all be too easy? (no offense Joerg, couldn't resist, I know that you are one of the best out there, we have done business before together, a real pleasure) (bytheway, soon more work is coming your way) Cheers Klaus
Reply by ●July 21, 20172017-07-21
On 2017-07-21 04:23, klaus.kragelund@gmail.com wrote:> On Friday, 21 July 2017 00:30:15 UTC+2, Joerg wrote: >> On 2017-07-20 15:02, Jim Thompson wrote: >>> On Thu, 20 Jul 2017 14:56:32 -0700, Joerg >>> <news@analogconsultants.com> wrote: >>> >>>> On 2017-07-20 14:38, Jim Thompson wrote: >>>>> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin >>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>> >>>>>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson >>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>>> >>>>>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin >>>>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>>>> >>>>>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson >>>>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin >>>>>>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> I'm simulating a flyback switcher and noticed that >>>>>>>>>> any K < 1 in the transformer radically slows down >>>>>>>>>> the sim, which is annoyingly slow already... 90 >>>>>>>>>> seconds to sim 60 ms of startup and a little pulsed >>>>>>>>>> load blip. Maybe 6:1 slower with a little leakage >>>>>>>>>> inductance. So I only include leakage inductance to >>>>>>>>>> tweak the snubber. >>>>>>>>> >>>>>>>>> You have to use Mikey's idealized components... fast, >>>>>>>>> but... ...Jim Thompson >>>>>>>> >>>>>>>> Using a discrete inductor to simulate the leakage >>>>>>>> inductance is no faster. Nice try, JL. >>>>>>> >>>>>>> What happened to LTspice's "fastest simulator ever" >>>>>>> ?>:-} ...Jim Thompson >>>>>> >>>>>> I have no idea how fast this would run in some other >>>>>> simulator, or if the leakage L would matter as much. But >>>>>> since I'm using an LTC3803, probably no other software >>>>>> would work. >>>>> >>>>> That's the problem with LT, and Analog Devices and sometime >>>>> TI... if your model will run on only your proprietary >>>>> simulator, what the f**k good is it? >>>>> >>>> >>>> The beauty is that there _is_ a model and it usually is a good >>>> compromise between "real" and behavioral simulation. With other >>>> mfgs you eitehr get no model at all or one that has no >>>> behavioral parts and where you can have an extensive dinner in >>>> town and the sim still won't be past 5%. >>>> >>>> I am certain that LTSpice has brought LTC more profits than any >>>> of their marketing efforts. >>>> >>>> [...] >>> >>> Suppose that LT parts are only a percentage of those parts in my >>> system, and there are parts from AD and TI, models of which won't >>> run on LTspice? Now what? I think it's a universally DUMB >>> marketing strategy. >>> >> >> Au contraire. When cost isn't critical but R&D time is of the >> essence I always default to LTC parts. Just like everyone around me >> does. Mission accomplished, I'd say. >> >> >>> If I was in the jelly-bean-user business I wouldn't buy any part >>> whose model wasn't Berkeley-Spice-compliant. >>> >> >> If you work in super-jelly-bean mode you will. Because the 10c >> switcher chip from Asia will only come with a skimpy datasheet and >> there is no model at all but it costs less than the 18c domestic >> IC. >> > I have never used a LT part, the costs are simply too high, doing > almost only high volume products >Yes, for high-volume their products make no sense.> Just for fun, needing an analog mux, searching Digikey came up with > 2.5USD for the cheapest LT (LTC222), and the cheapest comparable > product was the good old 74HC4066D, at a price of 9 US cents (almost > 30 times cheaper) > > Just try to search for the cheapest LT opamp: > > https://www.digikey.com/products/en/integrated-circuits-ics/linear-amplifiers-instrumentation-op-amps-buffer-amps/687?FV=ffe002af%2Cfffc00a1&mnonly=0&ColumnSort=1000011&page=1&stock=0&pbfree=0&rohs=0&cad=0&datasheet=0&nstock=0&photo=0&nonrohs=0&newproducts=0&k=opamp&quantity=&ptm=0&fid=0&pageSize=25&pkeyword=opamp > > That is really some sort of advanced marketing joke > > Again, the cheapest LT is 10 times more expensive than the cheapest > alternative > > Don't we have an obbligation to select the best part and not let it > all be too easy?We do but the cheapest part is not always the best. Sometimes I design higher end gear which is mission-critical. Cost is not very important but they need a very thoroughly vetted solution within a short time. Then LTC wins hands-down. The other upside is their support. Their app EEs know their stuff and you can get access to their IC designers. Often I have to do very unorthodox stuff with a chip, what medical people call "off-label use". With most other companies the answer is "That is not what the IC is intended for" but with LTC it is more like "Interesting! Let's see if this can be done safely". However, lately they seem to be losing their sizzle. For example, right now I am searching for a forward converter chip that can be tied into LTSpice and their newer ones do not have a model. Then the LTC advantage goes out the window. (no offense Joerg, couldn't resist, I know that you> are one of the best out there, we have done business before together, > a real pleasure) (bytheway, soon more work is coming your way) >Thanks. As long as it's nothing urgent over the next six weeks because one client has just loaded me with a project. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 21, 20172017-07-21
"John Larkin" wrote in message news:dub2nctc478iel0eg9mslak3la5d6bi29t@4ax.com... On Thu, 20 Jul 2017 15:02:16 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Thu, 20 Jul 2017 14:56:32 -0700, Joerg <news@analogconsultants.com> >wrote: > >>On 2017-07-20 14:38, Jim Thompson wrote: >>> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin >>> <jjlarkin@highland_snip_technology.com> wrote: >>> >>>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin >>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>> >>>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson >>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>>> >>>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin >>>>>>> <jjlarkin@highland_snip_technology.com> wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I'm simulating a flyback switcher and noticed that any K < 1 in the >>>>>>>> transformer radically slows down the sim, which is annoyingly slow >>>>>>>> already... 90 seconds to sim 60 ms of startup and a little pulsed >>>>>>>> load >>>>>>>> blip. Maybe 6:1 slower with a little leakage inductance. So I only >>>>>>>> include leakage inductance to tweak the snubber. >>>>>>> >>>>>>> You have to use Mikey's idealized components... fast, but... >>>>>>> >>>>>>> ...Jim Thompson >>>>>> >>>>>> Using a discrete inductor to simulate the leakage inductance is no >>>>>> faster. Nice try, JL. >>>>> >>>>> What happened to LTspice's "fastest simulator ever" ?>:-} >>>>> >>>>> ...Jim Thompson >>>> >>>> I have no idea how fast this would run in some other simulator, or if >>>> the leakage L would matter as much. But since I'm using an LTC3803, >>>> probably no other software would work. >>> >>> That's the problem with LT, and Analog Devices and sometime TI... if >>> your model will run on only your proprietary simulator, what the f**k >>> good is it? >>> >> >>The beauty is that there _is_ a model and it usually is a good >>compromise between "real" and behavioral simulation. With other mfgs you >>eitehr get no model at all or one that has no behavioral parts and where >>you can have an extensive dinner in town and the sim still won't be past >>5%. >> >>I am certain that LTSpice has brought LTC more profits than any of their >>marketing efforts. >> >>[...] > >>Suppose that LT parts are only a percentage of those parts in my >>system, and there are parts from AD and TI, models of which won't run >>on LTspice? Now what? I think it's a universally DUMB marketing >>strategy.>It's TI's fault if LT Spice won't run their models.>ADI will be transitioning to LT Spice, I've heard. Maybe that's why >they bought LT.Oh dear... as he says, loudly, in a McEnro voice..."You can't be serious.." That is truly a delusional view, says he, hitting his head against the wall... Companies buy companies because the bought companies are eating onto the buying companies revenues. The buying company wants the, now get this, the *Customers* of the bought company, and secondly, their *products* that customers *buy*. LT gets billions of revenue from paying customers, that's what ADI want and bought. Dah.... LTSpice is just a nice icing on the cake sort of thing. If it ceased to exist, it would make F'all difference. That's reality. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●July 21, 20172017-07-21
On Fri, 21 Jul 2017 04:23:50 -0700 (PDT), klaus.kragelund@gmail.com wrote:>On Friday, 21 July 2017 00:30:15 UTC+2, Joerg wrote: >> On 2017-07-20 15:02, Jim Thompson wrote: >> > On Thu, 20 Jul 2017 14:56:32 -0700, Joerg <news@analogconsultants.com> >> > wrote: >> > >> >> On 2017-07-20 14:38, Jim Thompson wrote: >> >>> On Thu, 20 Jul 2017 14:31:49 -0700, John Larkin >> >>> <jjlarkin@highland_snip_technology.com> wrote: >> >>> >> >>>> On Thu, 20 Jul 2017 13:02:23 -0700, Jim Thompson >> >>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>> >> >>>>> On Thu, 20 Jul 2017 12:26:42 -0700, John Larkin >> >>>>> <jjlarkin@highland_snip_technology.com> wrote: >> >>>>> >> >>>>>> On Thu, 20 Jul 2017 12:05:52 -0700, Jim Thompson >> >>>>>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>>>> >> >>>>>>> On Thu, 20 Jul 2017 11:39:25 -0700, John Larkin >> >>>>>>> <jjlarkin@highland_snip_technology.com> wrote: >> >>>>>>> >> >>>>>>>> >> >>>>>>>> >> >>>>>>>> I'm simulating a flyback switcher and noticed that any K < 1 in the >> >>>>>>>> transformer radically slows down the sim, which is annoyingly slow >> >>>>>>>> already... 90 seconds to sim 60 ms of startup and a little pulsed load >> >>>>>>>> blip. Maybe 6:1 slower with a little leakage inductance. So I only >> >>>>>>>> include leakage inductance to tweak the snubber. >> >>>>>>> >> >>>>>>> You have to use Mikey's idealized components... fast, but... >> >>>>>>> >> >>>>>>> ...Jim Thompson >> >>>>>> >> >>>>>> Using a discrete inductor to simulate the leakage inductance is no >> >>>>>> faster. Nice try, JL. >> >>>>> >> >>>>> What happened to LTspice's "fastest simulator ever" ?>:-} >> >>>>> >> >>>>> ...Jim Thompson >> >>>> >> >>>> I have no idea how fast this would run in some other simulator, or if >> >>>> the leakage L would matter as much. But since I'm using an LTC3803, >> >>>> probably no other software would work. >> >>> >> >>> That's the problem with LT, and Analog Devices and sometime TI... if >> >>> your model will run on only your proprietary simulator, what the f**k >> >>> good is it? >> >>> >> >> >> >> The beauty is that there _is_ a model and it usually is a good >> >> compromise between "real" and behavioral simulation. With other mfgs you >> >> eitehr get no model at all or one that has no behavioral parts and where >> >> you can have an extensive dinner in town and the sim still won't be past 5%. >> >> >> >> I am certain that LTSpice has brought LTC more profits than any of their >> >> marketing efforts. >> >> >> >> [...] >> > >> > Suppose that LT parts are only a percentage of those parts in my >> > system, and there are parts from AD and TI, models of which won't run >> > on LTspice? Now what? I think it's a universally DUMB marketing >> > strategy. >> > >> >> Au contraire. When cost isn't critical but R&D time is of the essence I >> always default to LTC parts. Just like everyone around me does. Mission >> accomplished, I'd say. >> >> >> > If I was in the jelly-bean-user business I wouldn't buy any part whose >> > model wasn't Berkeley-Spice-compliant. >> > >> >> If you work in super-jelly-bean mode you will. Because the 10c switcher >> chip from Asia will only come with a skimpy datasheet and there is no >> model at all but it costs less than the 18c domestic IC. >> >I have never used a LT part, the costs are simply too high, doing almost only high volume products > >Just for fun, needing an analog mux, searching Digikey came up with 2.5USD for the cheapest LT (LTC222), and the cheapest comparable product was the good old 74HC4066D, at a price of 9 US cents (almost 30 times cheaper) > >Just try to search for the cheapest LT opamp: > >https://www.digikey.com/products/en/integrated-circuits-ics/linear-amplifiers-instrumentation-op-amps-buffer-amps/687?FV=ffe002af%2Cfffc00a1&mnonly=0&ColumnSort=1000011&page=1&stock=0&pbfree=0&rohs=0&cad=0&datasheet=0&nstock=0&photo=0&nonrohs=0&newproducts=0&k=opamp&quantity=&ptm=0&fid=0&pageSize=25&pkeyword=opamp > >That is really some sort of advanced marketing joke > >Again, the cheapest LT is 10 times more expensive than the cheapest alternative > >Don't we have an obbligation to select the best part and not let it all be too easy? (no offense Joerg, couldn't resist, I know that you are one of the best out there, we have done business before together, a real pleasure) (bytheway, soon more work is coming your way) > >Cheers > >KlausMost LT parts are too expensive. The LTC3803 switcher controller isn't bad at $1.32. For a long time, the LT1028 was the lowest noise opamp available. They have some nice octal DACs. We've used over 2K pieces of their 250 MHz ADC, the LTC2242, at $60 each. It's very good. LTC parts are worth it when they make a product seriously better. Their best product is LT Spice, for free. -- John Larkin Highland Technology, Inc lunatic fringe electronics
