On Sun, 23 Jul 2017 04:51:34 -0700 (PDT), klaus.kragelund@gmail.com wrote:>On Sunday, 23 July 2017 07:05:10 UTC+2, John Larkin wrote: >> On Sat, 22 Jul 2017 21:00:58 -0700, Jim Thompson >> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >> >On Sat, 22 Jul 2017 20:35:43 -0700, John Larkin >> ><jjlarkin@highlandtechnology.com> wrote:[snip]>> >> >> >>Who needs a Spice model for a comparator? I sure don't. >> > >> >You apparently only do _one_device_at_a_time_ simulations? >> > >> >No whole-system simulations? >> > >> > ...Jim Thompson >> >> My systems are way too complex to simulate. I only sim one little >> section if I think there's any risk. Lots of products don't need >> simulation at all; design it, lay out the board, and sell it. For a >> complex product, I can do that sooner than someone could sim it. >> > >"Way to complex to simulate"? > >I think you meant to say you don't want to spend the time to simulate your systems? > >We routinely do complete system simulations, cross discliplinary ones, mixing motors, power electronics and even C-code) > >What is complex to simulate is radiated EMC, we have not done that yet, but it's in the pipeline > >Cheers > >KlausOften a chip that I'm designing is _not_ a stand-alone system all by itself... there are standard off-the-shelf parts all around it. Thus my need to simulate a full system to ensure that everything "plays" together properly. It's rare when all those auxiliary components are the same brand... thus there's no way I can use a single proprietary simulator. If there are components without Berkeley-Spice-compliant models I'm forced to roll my own... not that it's a terrible bother... I'm rather good at it... customers pay me to 'write' such models (*) for their products ;-) (*) Usually completely behavioral... thus no proprietary IP is disclosed via the model.... the customers like that >:-} ...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.
LT spice, leakage inductance
Started by ●July 20, 2017
Reply by ●July 23, 20172017-07-23
Reply by ●July 23, 20172017-07-23
On Sun, 23 Jul 2017 04:47:28 -0700 (PDT), klaus.kragelund@gmail.com wrote:>On Sunday, 23 July 2017 02:01:51 UTC+2, k...@notreal.com wrote: >> On Sat, 22 Jul 2017 12:05:37 -0700 (PDT), Klaus Kragelund[snip]>> > >> >I have worked at 6 different firms and I have never come across any colleagues using a single LT part. Only here at SED >> >> So you're saying that LT doesn't actually sell parts in the $Bs? Or >> are you saying that everyone who uses those $Bs worth of LT parts is >> here on SED? >> >I am saying that no-one I know of in the real world (if SED is not a real world) uses LT parts and I know several hundreds HW designers > >The wild claim that LTspice would spawn 7 digit generated extra sales is totally unsupported and sounds like something Trump could say, or not even him, like 100 times Trump.Or Larkin >:-}> >Proof it by looking at the 2001 1 billion rise in sales that should be visible in the financial statement (it was 2001 when Switchercad became LTspice, right) > >Cheers > >Klaus...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 23, 20172017-07-23
On Sun, 23 Jul 2017 07:56:31 -0700, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Sun, 23 Jul 2017 04:47:28 -0700 (PDT), klaus.kragelund@gmail.com >wrote: >[snip]>> >>The wild claim that LTspice would spawn 7 digit generated extra sales is totally unsupported and sounds like something Trump could say, or not even him, like 100 times Trump. > >Not annual parts sales, but sales price of LTC to ADI. If I had meant >parts sales, I would have specified a timebase, as in "annual" or >"accumulated" or something. I talked to an LTC-ADI transition team, >and they agreed that LT Spice mattered in the acquisition. So, one >billion added out of 15 is not a wild claim. > >I'd guess more.Q.E.D. >:-} ...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 23, 20172017-07-23
On Sun, 23 Jul 2017 04:51:34 -0700, klaus.kragelund wrote:> On Sunday, 23 July 2017 07:05:10 UTC+2, John Larkin wrote: >> On Sat, 22 Jul 2017 21:00:58 -0700, Jim Thompson >> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >> >On Sat, 22 Jul 2017 20:35:43 -0700, John Larkin >> ><jjlarkin@highlandtechnology.com> wrote: >> > >> >>On Sat, 22 Jul 2017 12:57:59 -0700, Jim Thompson >> >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >> >> >>>On Sat, 22 Jul 2017 12:39:45 -0700, John Larkin >> >>><jjlarkin@highlandtechnology.com> wrote: >> >>> >> >>>>On Sat, 22 Jul 2017 12:11:44 -0700, Jim Thompson >> >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>> >> >>>>>On Sat, 22 Jul 2017 12:05:37 -0700 (PDT), Klaus Kragelund >> >>>>><klauskvik@hotmail.com> wrote: >> >>>>> >> >>>>>>On Saturday, July 22, 2017 at 8:40:24 PM UTC+2, Joerg wrote: >> >>>>>>> On 2017-07-22 07:43, John Larkin wrote: >> >>>>> >> >>>>>[snip] >> >>>>>>> > >> >>>>>>> > Colleges use LT Spice all over the world. It has its own >> >>>>>>> > culture. >> >>>>>>> > Culture matters. >> >>>>>>> > >> >>>>>>> > >> >>>>>>> I'll second all that. 100%. >> >>>>>>> >> >>>>>>> I don't know how much sales I generated for LTC because of >> >>>>>>> LTSpice but it likely was 7-digit. And I am only one of many. >> >>>>>>> >> >>>>>>I don't believe that for a second >> >>>>>> >> >>>>>>I have worked at 6 different firms and I have never come across >> >>>>>>any colleagues using a single LT part. Only here at SED >> >>>>>> >> >>>>>>Cheers >> >>>>>> >> >>>>>>Klaus >> >>>>> >> >>>>> {>:-} >> >>>>> >> >>>>>Right down there with Microchip Analog parts ;-) >> >>>>> >> >>>>> ...Jim Thompson >> >>>> >> >>>>Some of their parts are quite good, like their comparators. >> >>> >> >>>[Begin personal opinion (legal disclaimer) mode ;-] >> >>> >> >>>Their Spice models are the suckiest of the sucky. >> >>> >> >>> ...Jim Thompson >> >> >> >>Who needs a Spice model for a comparator? I sure don't. >> > >> >You apparently only do _one_device_at_a_time_ simulations? >> > >> >No whole-system simulations? >> > >> > ...Jim Thompson >> >> My systems are way too complex to simulate. I only sim one little >> section if I think there's any risk. Lots of products don't need >> simulation at all; design it, lay out the board, and sell it. For a >> complex product, I can do that sooner than someone could sim it. >> >> > "Way to complex to simulate"? > > I think you meant to say you don't want to spend the time to simulate > your systems?I assume he meant *computing* time. Whole system simulation requires a lot of h/ware grunt unless you enjoy staring blankly at a computer screen. I find it far better just to simulate the relevant circuit fragments for this reason.
Reply by ●July 23, 20172017-07-23
On Sun, 23 Jul 2017 08:02:37 -0700, John Larkin wrote:> Buy a six-pack?We don't have those in the UK. Ours tend to come in fours of either 500ml or a pint per can. And our beer is more hoppy/less malty than yours.
Reply by ●July 23, 20172017-07-23
On Sun, 23 Jul 2017 16:28:26 -0000 (UTC), Cursitor Doom <curd@notformail.com> wrote:>On Sun, 23 Jul 2017 04:51:34 -0700, klaus.kragelund wrote: > >> On Sunday, 23 July 2017 07:05:10 UTC+2, John Larkin wrote: >>> On Sat, 22 Jul 2017 21:00:58 -0700, Jim Thompson >>> <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>> >On Sat, 22 Jul 2017 20:35:43 -0700, John Larkin >>> ><jjlarkin@highlandtechnology.com> wrote: >>> > >>> >>On Sat, 22 Jul 2017 12:57:59 -0700, Jim Thompson >>> >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >> >>> >>>On Sat, 22 Jul 2017 12:39:45 -0700, John Larkin >>> >>><jjlarkin@highlandtechnology.com> wrote: >>> >>> >>> >>>>On Sat, 22 Jul 2017 12:11:44 -0700, Jim Thompson >>> >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>> >>> >>>>>On Sat, 22 Jul 2017 12:05:37 -0700 (PDT), Klaus Kragelund >>> >>>>><klauskvik@hotmail.com> wrote: >>> >>>>> >>> >>>>>>On Saturday, July 22, 2017 at 8:40:24 PM UTC+2, Joerg wrote: >>> >>>>>>> On 2017-07-22 07:43, John Larkin wrote: >>> >>>>> >>> >>>>>[snip] >>> >>>>>>> > >>> >>>>>>> > Colleges use LT Spice all over the world. It has its own >>> >>>>>>> > culture. >>> >>>>>>> > Culture matters. >>> >>>>>>> > >>> >>>>>>> > >>> >>>>>>> I'll second all that. 100%. >>> >>>>>>> >>> >>>>>>> I don't know how much sales I generated for LTC because of >>> >>>>>>> LTSpice but it likely was 7-digit. And I am only one of many. >>> >>>>>>> >>> >>>>>>I don't believe that for a second >>> >>>>>> >>> >>>>>>I have worked at 6 different firms and I have never come across >>> >>>>>>any colleagues using a single LT part. Only here at SED >>> >>>>>> >>> >>>>>>Cheers >>> >>>>>> >>> >>>>>>Klaus >>> >>>>> >>> >>>>> {>:-} >>> >>>>> >>> >>>>>Right down there with Microchip Analog parts ;-) >>> >>>>> >>> >>>>> ...Jim Thompson >>> >>>> >>> >>>>Some of their parts are quite good, like their comparators. >>> >>> >>> >>>[Begin personal opinion (legal disclaimer) mode ;-] >>> >>> >>> >>>Their Spice models are the suckiest of the sucky. >>> >>> >>> >>> ...Jim Thompson >>> >> >>> >>Who needs a Spice model for a comparator? I sure don't. >>> > >>> >You apparently only do _one_device_at_a_time_ simulations? >>> > >>> >No whole-system simulations? >>> > >>> > ...Jim Thompson >>> >>> My systems are way too complex to simulate. I only sim one little >>> section if I think there's any risk. Lots of products don't need >>> simulation at all; design it, lay out the board, and sell it. For a >>> complex product, I can do that sooner than someone could sim it. >>> >>> >> "Way to complex to simulate"? >> >> I think you meant to say you don't want to spend the time to simulate >> your systems? > >I assume he meant *computing* time. Whole system simulation requires a >lot of h/ware grunt unless you enjoy staring blankly at a computer >screen.Not really. The LTspice sales pitch has got everyone's knickers in a bind if the simulation isn't done in 30 seconds. In the "good old days" simulations sometimes took days.>I find it far better just to simulate the relevant circuit >fragments for this reason.Might make you wonder how good the simulator you're using really is? I routinely simulate chips with THOUSANDS of transistors... might take an hour or so... but my customers prefer not to commit $100K over a seat-of-the-pants guess based on FRAGMENTS. ...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 23, 20172017-07-23
On Sun, 23 Jul 2017 09:40:13 -0700, Jim Thompson wrote:> Might make you wonder how good the simulator you're using really is? > > I routinely simulate chips with THOUSANDS of transistors... might take > an hour or so... but my customers prefer not to commit $100K over a > seat-of-the-pants guess based on FRAGMENTS.Well, I only use LT. And I still can't see any problems in adopting a block-level, modular approach to simulating a system. It's no more 'cheating' than using ideal op-amp models to save on time.
Reply by ●July 23, 20172017-07-23
On 2017-07-23 03:00, Kevin Aylward wrote:> "Joerg" wrote in message news:ethkgjFkhpdU1@mid.individual.net... > > On 2017-07-22 07:43, John Larkin wrote: >>> On Sat, 22 Jul 2017 08:42:45 +0100, "Kevin Aylward" >>> <kevinRemovAT@kevinaylward.co.uk>> wrote: >>> >>>>> "John Larkin" wrote in message >>>>> news:2r95nc5ls1rrm7cmp5ptn26kmlrroi6jpp@4ax.com... >>>>> >>>>> On Fri, 21 Jul 2017 21:25:00 +0100, "Kevin Aylward" >>>>> <kevinRemovAT@kevinaylward.co.uk>> wrote: >>>>> >>>>>>> "John Larkin" wrote in message >>>>>>> news:m794nclodso7tu7c9bihmic1cuqtuf4ufa@4ax.com... >>>>>>> >>>>>>> >>>>>>> >>>>>>>>> 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 ut bwould make F'all difference. That's reality. >>>>>>> >>>>>>>>> It's a major sales tool. >>>>>>> >>>>>>> No. Its a sales tool. >>>>>>> >>>>>>>>> People pay for sales tools. >>>>>>> >>>>>>> Sure, but not $1B. >>>>>>> >>>>>>>>> When I made the suggestion to the LT/ADI transition team, nobody >>>>>>>>> contradicted me. I'd guess that LT Spice added at least a billion >>>>>>>>> dollars to the deal. >>>>>>> >>>>>>>>> Complete and utter nonsense. >>>>>>> >>>>>>>>> Like, Cadence do about $2B revenue. Candace is THE mainstream >>>>>>>>> de-facto >>>>>>>>> system in IC design. You know, the things that the world runs on. >>>>>>> >>>>>>>>> You're trying to claim that the LT Freebee is on a par in value. >>>>>>> >>>>>>>>> LT do about $2B in physical sales. You are effectively trying >>>>>>>>> to claim >>>>>>>>> that >>>>>>>>> if LTSpice didn't exist, LT would lose like $100Ms of dollars. >>>>>>>>> Bullshit. >>>>>>> >>>>>>>>> You really need to stand back and think about the big picture. >>>>>>> >>>>>>>>> People buy LT parts because of the performance, not because of a >>>>>>>>> simulater. >>>>>>>>> Period. >>>>>>> >>>>>>>>> LTSpice only has to improve sales by say, a million or so to >>>>>>>>> justify its >>>>>>>>> existence, i.e Mike's salary :-). I agree, it probably does >>>>>>>>> that, and such >>>>>>>>> a >>>>>>>>> salary pisses me off no end.... >>>>>>>>> >>>>> >>>>>>> In summary, you are jealous of LT Spice and its author. >>>>> >>>>> The summary, is that some here have absolutely no idea whatsoever >>>>> of the >>>>> value of some marketing tools. >>>>> >>>>> AD do about $3B in product. >>>>> >>>>> How much would it cost to for any company to get the Spice3 code, >>>>> and hire >>>>> someone to write a GUI for it? Like a few $100k ? >>>>> >>>>> Hint: you can buy 3rd party GUI tools that have schematic capture >>>>> as a drop >>>>> in component. >>>>> >>>>> Do your really think all the other companies are so totally stupid >>>>> that they >>>>> wouldn't invest a few hundred $ to produce a full featured Spice to >>>>> give >>>>> away for free if it would net them a $1B more a year in revenue. >>>>> Get real. >>>>> >>>>> >>>>> -- Kevin Aylward >>>>> http://www.anasoft.co.uk - SuperSpice >>>>> http://www.kevinaylward.co.uk/ee/index.html >>> >>> ADI paid 14.8 big ones for LTC. LTC charges at least 2x what other >>> people charge for similar functions. LT Spice helps them do that. >>> >>> TI's sim stuff won't even run on my PC for some reason. So I use LTC >>> parts unless the cost impact is extreme. >>> >>> TPS54302 is a great little switcher, but I had to spend an afternoon >>> breadboard fiddling to figure out all my needed compansations with >>> various caps and voltages. I'll use a lot of them, so it was worth it. >>> But neither TI's data sheet nor their software was much help. >>> >>> Colleges use LT Spice all over the world. It has its own culture. >>> Culture matters. >>> > >> I'll second all that. 100%. > >> I don't know how much sales I generated for LTC because of LTSpice but >> it likely was 7-digit. And I am only one of many. > > I just don't believe you.So why do you think that a higher level engineer from them came out here? I am 2-3h from the Bay Area. He didn't even let me pay lunch. On Friday I inquired about some of their ICs that would be a good fit for a new project but have no models. They immediately offered giving me eval kits if they can't secure models from the factory. Companies do not offer such levels of support if there isn't a good resulting sales volume behind many of those projects.> ... I think you cant evaluate you own design > strategy so are deluding yourself. >Huh? But it won't matter, my clients think otherwise.> I did used to do board level design, for many years. I can evaluate my > design strategy, honestly. I check out all viable parts from the data > sheets. It don't take long. >Many of my designs are unorthodox and would not be possible without having simulator models of the chips available. Datasheets only go so far. For example, they will not tell you whether driving the compensation pin of a switcher chip is kosher. Only the simulator plus endorsement from the manufacturer will. LTC provides both, most other manufacturers provide neither.> Spice will not make you design in any part. The performance of the real > part will. Period. End Of. >Sorry, but that is not correct.> If the fundamental basis of an engineering design is, to use an LT part, > because they provided the software, then that would make such a designer > a very bad engineer. Its that simple. >As I said, my clients know otherwise.> I don't believe that you are a bad designer. If you don't compare your > selection of an LT part, with other vender's parts, then you would make > you a bad designer. > > For a good designer, its just an irritant to get a model together that > is good enough to do viability sims that are confirmed on the bench. > There is enough free/inexpensive spices around, especially by the > competing vendors aligning with say, the likes of TINA and TI, with > models that mean alternatives to LT parts can be checked out in spice. >I have used a lot of simulators. The best so far is LTSpice. PSpice used to be ok in the DOS days (I had a Microsim license, well, still have) but I found recent versions to be way too buggy for my taste. Electronics Webbench and stuff, sorry, that does not cut it for me. Anyhow, many designs can't really happen unless there is a simulator model. In most cases it does no good to spend days at the lab bench, figure out a nifty way to use a chip "off-label" and then the manufacturer refuses to even comment on that way of using it. Which means you cannot submit. So for those designs I prefer manufacturers such as LTC who do support me all the way. Just like John does, and many others. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 23, 20172017-07-23
wrote in message news:632a6872-a842-4539-93d7-e3cc16ac9d82@googlegroups.com...>On Sunday, July 23, 2017 at 11:58:44 AM UTC+2, Kevin Aylward wrote: >> >wrote in message >> >news:2eb4a887-1683-4204-9a70-6606e5e44acc@googlegroups.com... > >> On Saturday, July 22, 2017 at 9:42:58 AM UTC+2, Kevin Aylward wrote: > [..] > >>> How much would it cost to for any company to get the Spice3 code, > >> and hire someone to write a GUI for it? Like a few $100k ? > >> >Looking e.g. at the ngspice open source project, to get from the > >SPICE3 code to something comparable to LTspice takes at least >>> >50 man-years, and then we are not talking code monkeys. > >> er... ngspice *exists*. Dah.... Anyone can use it and give it away. So >> that >> part of the deal is *already* done.>You said starting from SPICE3, not ngspice.Splitting hairs. I obviously meant ANY bit of spice code that was available. I I were to start from scratch, I would start from ngspice. It has a lot of very good features. Its too late for me now because I have way too many extra features not in ngspice in my version.> It took me 4 years part time in *evenings* to do 150k lines of code to do > the GUI. However...today...there are class libraries that do it all for >> you!!! > >> No one needs to write a GUI from scratch today. > >> There is a 3rd party gui toolkit, that generates the exact same drawing >> capabilities that is in Electronic Workbench/Multisim. Its been available >> for over 15 years. A grand or so, I believe. > >> "Build your own Multisim like circuit simulation and design product" > >> http://www.ucancode.net/Circuit-Design-interactive-simulation-Animation-analysis-layout-visualization-VC-Source-Code.htm > >> E-XD++ toolkit>It looks like shit.Well, that's Multisim for you... Its still way, way better that the bigger shit GUI of LTSpice.>Besides that, a screenshot is not the same >as a working GUI for a circuit simulator. How about its library >and attribute editors, its netlister, its help system, its macro >facilities etc.?That is just one example. The point is that there are graphics libs all over the place that allow one to generate a GUI without a lot of effort. I think you're missing the point. I know exactly how much work is involved in doing a hierarchical netlister :-) I would say, it took me < 2 man years for SS for the core functions. If I were to start from scratch, and was already familiar with the graphics libraries out there, I estimate that it would be < 12 months. ok, maybe I am more productive than most. Some might say 75k lines of code a man year, whilst pulling down a fulltime analog day job is unusual... -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
Reply by ●July 23, 20172017-07-23
"Joerg" wrote in message news:etjs8hF5d1eU1@mid.individual.net...>> The wild claim that LTspice would spawn 7 digit generated extra sales >> is totally unsupported and sounds like something Trump could say, or >> not even him, like 100 times Trump. >>Obviously I can't reveal details but I developed a circuit around a >PFC-capable chip from LTC that enabled me to do something that hasn't been >done before (and was considered impossible) because it allowed direct >access to the internal modulator. This is in mass production now, >regardless of the fact that each chip costs above $2. Because it's worth it >and makes the client money.>Then there was a boost converter chip that I used in very unorthodox ways >because LTSpice lets me simulate driving it via the compensator pin. I >discovered a shortcoming on that chip, had a chat with the guys at LTC >about it and ... shortly thereafter an A version came out with that issue >fixed. Try that with another manufacturer.None of that has any baring as to whether LTSpice generates large extra revenues. If LTSpice didn't exist, LT would have had to make models for Spice3/XSpice compatible simulators. All this this shit about LTSpice has propriety models that are way faster than the Spice3/XSpice, is just that, bullshit. Sure, LTSPice is fast on its own, but it it aint enough to make a difference in the real world. XSpice is a full event driven mixed mode simulator. All the "propriety model" stuff like ideal logic and is all handled in the wash in XSpice, and get this, its compatible to any other vender that uses XSpice. Even without using the mixed mode stuff, a behavioural SMPS in SS can run in 5 Secs. You are simply confused on buying parts that do a job correctly, and simulating it. If another part could do the same job , is available and cheaper, and if you don't use this other part, then I wouldn't hire you to design my products. Period. -- Kevin Aylward http://www.anasoft.co.uk - SuperSpice http://www.kevinaylward.co.uk/ee/index.html
