Proprietary SMPS design tools, what for?
in [Design]
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From: krw on 9 Sep 2009 19:46 On Wed, 09 Sep 2009 03:21:32 -0400, "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote: > >krw wrote: >> >> It's not *that* big of a hose. > > > I don't even want to know how you keep your hose up. ;-) Concrete.
From: JosephKK on 10 Sep 2009 02:44 On Mon, 07 Sep 2009 16:22:20 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Phil Hobbs wrote: >> Joerg wrote: >>> JosephKK wrote: >>>> On Thu, 03 Sep 2009 16:50:11 -0400, Spehro Pefhany >>>> <speffSNIP(a)interlogDOTyou.knowwhat> wrote: >>>> >>>>> On Wed, 02 Sep 2009 09:54:28 -0700, Jim Thompson >>>>> <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: >>>>> >>>>>> On Wed, 02 Sep 2009 16:38:34 GMT, qrk <SpamTrap(a)spam.net> wrote: >>>>>> >>>>>>> On Tue, 01 Sep 2009 12:25:07 -0700, Joerg <invalid(a)invalid.invalid> >>>>>>> wrote: >>>>>>> >>>>>>>> Tim Wescott wrote: >>>>>>>>> On Tue, 01 Sep 2009 09:09:59 -0700, Joerg wrote: >>>>>>>>> >>>>>>>>>> Today I and probably others received the announcement of the >>>>>>>>>> umpteenth >>>>>>>>>> SMPS "iteractive design simulator", EDesign Studio or whatever >>>>>>>>>> from ST. >>>>>>>>>> I am not even going to try it. I've hung up on those things a >>>>>>>>>> long time >>>>>>>>>> ago, after WebBench from National flagged the third of my >>>>>>>>>> designs as >>>>>>>>>> "cannot be ..." (all in mass production now). The millisecond >>>>>>>>>> you try >>>>>>>>>> something unorthodox which I always tend to do they fall off >>>>>>>>>> the cliff >>>>>>>>>> anyhow. So I use LTSpice for everything. Since it seems that >>>>>>>>>> only LTC >>>>>>>>>> furnishes good SPICE models for their PWM parts this has >>>>>>>>>> brought them >>>>>>>>>> quite some business from my side. >>>>>>>>>> >>>>>>>>>> What's the point with all this proprietary stuff? >>>>>>>>> Because most designers don't really have a clue about what >>>>>>>>> they're doing, and don't want to. So spoon-feeding them >>>>>>>>> super-safe circuits that are designed by a machine that's >>>>>>>>> designed by some zit-faced kid in India will lead them to better >>>>>>>>> success than trying to teach them basic principals. >>>>>>>>> >>>>>>>>> (Note that LTSpice _is_ proprietary, and part of the reason the >>>>>>>>> models for Linear parts work better in it is because they use >>>>>>>>> the proprietary features of LTSpice, not 'regular' spice models >>>>>>>>> which LTSpice can't use as fast as it's 'own' stuff). >>>>>>>>> >>>>>>>> Sure, but: I can use other companies' stuff and just accept a >>>>>>>> slower simulation speed because the sub-circuits become kind of >>>>>>>> hefty. Gets me to the goal line while those online calculators >>>>>>>> never did. I have yet to encounter a situation where LTSpice >>>>>>>> would reject a proper SPICE model of a non-LTC part. >>>>>>>> >>>>>>>> >>>>>>>>>> Why can't they invest >>>>>>>>>> their time in much more useful activities like furnishing >>>>>>>>>> proper SPICE >>>>>>>>>> subcircuits? >>>>>>>>> Because in most companies marketing is an expense, not a profit >>>>>>>>> center, and a proper SPICE circuit is 'too expensive'. >>>>>>>>> >>>>>>>>> Why did Zilog spend 20 years driving away any designer who >>>>>>>>> wasn't going to order 20000 parts at a whack? Because they're >>>>>>>>> stupid! After they taught all those kids to shun them, they had >>>>>>>>> to go and convince them (me amongst them) to use Zilog after all >>>>>>>>> -- and I still won't. >>>>>>>>> >>>>>>>> And here I thought they had already gone belly-up :-) >>>>>>>> >>>>>>>> >>>>>>>>>> The most daft answer I got was along the lines of "We'll >>>>>>>>>> only create a SPICE model if the business volume warrants it". >>>>>>>>>> As if I'd >>>>>>>>>> be so stupid to promise them sales volume before test driving. >>>>>>>>>> Long >>>>>>>>>> story short that business volume went to a competitor. >>>>>>>>> When you say 'daft', your questions answer themselves. >>>>>>>>> >>>>>>>> :-) >>>>>>> I'm amazed at the support the LT gives. Even for us little guys, we >>>>>>> are given eval boards and lots of support from their field engineer. >>>>>>> Plus, a decent way to simulate their switchers which I tend to use in >>>>>>> unconventional ways that WebBench couldn't deal with. WebBench is so >>>>>>> slow and limiting I gave up. The one National switcher controller I >>>>>>> did use required doing a prototype board with a couple different >>>>>>> configurations of the switcher. Fortunately, the overly simplified >>>>>>> model of the NS part I created in LTspice was close enough to >>>>>>> reality. >>>>>>> >>>>>>> Our LT rep said most of LT's business is smaller companies. >>>>>> Part of the issues is CHEAP-CHEAP. A few years ago I was approached >>>>>> by a major ANALOG company (you can guess who :-) to model a complex >>>>>> device. I figured about a week of my time to do it proper justice. >>>>>> Too expensive for them :-( >>>>>> ...Jim Thompson >>>>> Seems like they (LT) decided to solve the problem of creating models >>>>> efficiently, rather than create bespoke models one at a time-- which >>>>> is why they can claim to have more SMPS chip models than all the rest. >>>>> >>>>> "I see no reason for the continuing existence of AMD " >>>>> -- Mike E. >>>> >>>> I can see at least one good reason to keep AMD, a sufficient thorn in >>>> Intel's side to keep them halfway honest. There may be more reasons. >>> >>> >>> AMD can make darn good processors. My laptop has a 64-bit Turion in >>> there and while older that thing still gives newer machines at clients >>> a run for their money when doing sims. >>> >>> Best was a session where we did hands-on design on Cypress PSoC. About >>> eight guys starting the compile at the same time. When I signaled mine >>> was done a couple of guys across the table said "WHAT?". They had >>> freaking expensive Thinkpads. >>> >> >> My once-and-future Linux cluster had 14 Opterons, which for FP-intensive >> tasks blew the doors off Xeons of the same vintage. >> > >AMD engineering seems to be really good. The sales folks, well, maybe >not so much. > >This laptop with the Turion is about four years old and back then it >regularly blew expensive desktops at clients out of the water. We often >run sims concurrently to get data for various configurations quickly. So >except for some numeric part values it's the same files. The faces when >mine was finished and their "big machine" was at 75% completion were >priceless. > >Of course then it needs its AC adapter because it'll suck the battery >dry in under an hour when doing sims. Plus the fan on the Durabook is >very loud, quite annoying, and sends paper sailing off the desk. As a matter of track record AMD optimized FP performance instead of integer performance. They also optimize 64 bit performance over 32 bit performance. Intel chose differently.
From: Joerg on 10 Sep 2009 12:31
JosephKK wrote: > On Mon, 07 Sep 2009 16:22:20 -0700, Joerg <invalid(a)invalid.invalid> > wrote: > [...] >> This laptop with the Turion is about four years old and back then it >> regularly blew expensive desktops at clients out of the water. We often >> run sims concurrently to get data for various configurations quickly. So >> except for some numeric part values it's the same files. The faces when >> mine was finished and their "big machine" was at 75% completion were >> priceless. >> >> Of course then it needs its AC adapter because it'll suck the battery >> dry in under an hour when doing sims. Plus the fan on the Durabook is >> very loud, quite annoying, and sends paper sailing off the desk. > > As a matter of track record AMD optimized FP performance instead of > integer performance. They also optimize 64 bit performance over 32 > bit performance. Intel chose differently. Thanks, Joseph. That would explain why this now rather old processor is so blazingly fast on SPICE. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |