LTSpice LED parameters

That's my understanding (from a pretty good source). You can't import models to the (free) TINA. If it's not in their library, forget it. I have no idea if they're going to cripple it or not but I suspect it'll only run on the web and without things like optimization and noise analysis. They're certainly not going to give out free licenses to the full PSpice. Cadence doesn't work that way. ;-)

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krw
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I see them a lot in sub-1000/yr products. You are basically their model customer.

Anything in quantity, either they negotiated a hell of a deal, or there really isn't a better option.

Tim

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Reply to
Tim Williams

Face it: LT Spice does everything right.

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John Larkin         Highland Technology, Inc 

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John Larkin

'Cause for low volume, the cost of the box, connectors, switches etc. makes the cost of the stuff inside less important. And I tried the LT/AD part first and it worked.

George H.

Reply to
George Herold

Well, we weren't talking about you... :^)

Tim

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Reply to
Tim Williams

Not on a MacBook, it doesn't.

Reply to
whit3rd

Correction: It does everything *you* need (and I'm not so sure about) right.

Reply to
krw

I'll let you know. ADI is quoting us some LT parts. We'll see how close they can get to TI (and others).

Reply to
krw

Despite SS using the basic Spice3/XSpice engine, I use it extensively, daily in parallel with Cadence Virtuoso, because it has button press WC (Worse Case). I can run 100s of process corners with ease. Without WC, you don't have a design. Period.

-- Kevin Aylward

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Kevin Aylward

Maybe for ICs. At board level, wc design will either run the cost way up, or result in un-competitive specs. We set the specs so that most units pass test, and fix or trash the few that don't.

Real wc basically never happens. It's way too far out the probability curve.

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John Larkin         Highland Technology, Inc 
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John Larkin

Yep. I do the same, but use macros... I suppose I could make it a "button-press" with MacroExpress... which I use extensively to ease my workload. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Jim Thompson

TI's TINA models are mostly horrible. The OPA140 model won't converge unless the supplies are *exactly* symmetrical, and not very often even if they are.

Most of the board-level pspice models I've tried worked okay in LTspice.

Cheers

Phil Hobbs

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Phil Hobbs
[snip]

Didn't I write-up an OPA140 model for you that worked (~2015)?

Yes. Unfortunately a high percentage of LTspice models won't work with PSpice (or any other simulator) :-(

That's a huge pain. I might design-in some LTspice switchers if I could simulate them along with non-LT components.

So I just lead my clients to other vendors.

The Spice models I create run on ANY Spice-compliant simulator. (I check my models on LTspice as well as a number of other cheapy simulators... due to customer requests :-)

...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Jim Thompson

Is there something badly broken in the OSX version of wine?

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Jasen Betts

Opamp behavioral models seldom do power supplies right. I have one opamp sim where the amp generates 3KV into an unconnected power pin. Probably some pure current source inside.

Wish the real part would do that.

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John Larkin         Highland Technology, Inc 
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Reply to
John Larkin

Nope, as I recall you hacked with it a bit and then agreed that the TINA one was a mess.

Well, not the proprietary ones.

The only LTC part I've ever designed into a client's board is the LT1677, which had a combination of input CM range and output swing that I couldn't match with jellybeans without a lot of extra gingerbread. I'll probably design it out again next time round, because the next version is going to have an MCU in it that can do some of the fancy footwork.

I'm not that fond of circuit simulation, because the available models are so crappy. It's generally not a good enough use of my time to make better ones, so I've never bothered to get good at making models, just like I don't do my own PCB layouts. That's why I'm not that emotional about any of them.

Some small discrete designs are difficult to get really right without modelling, because it's axiomatic that every breadboard contains at least one perfect component that you'll never see again.

Cheers

Phil Hobbs

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Reply to
Phil Hobbs

Sort of. A quick check of the E-mails back-and-forth between us shows the problem to have been "LTspice can't cope with a noiseless resistor as a DC path, PSpice can" (as well as any simulator Berkeley-compliant)... it's simply a G-source... why LTspice can't cope with that, who the hell knows ?:-)

My complaints about LTspice are that so many are using it, yet it disobeys standard Spice rules right and left.

My dad actually had his service trucks labeled "We DON'T service Muntz TV's"

Maybe I should put up a banner "LTspice not supported" ... might cost me the business of the number of thumbs on one hand ?>:-}

...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Jim Thompson

Sure. Most will supply more power than they consume.

#MeToo

Reply to
krw

I like Spice because it trains my instincts. I am doing a really gnarly design right now that I really didn't understand until I Spiced it about 50 times and saw where the currents were actually going when. Then I could push things around, to simplify and optimize. The device power dissipation measurement thing is awesome, not something I'd want to do by hand... or on a breadboard.

We also leave commented Spice sims in project folders to help document why we did things. That can be really handy to have around a few years later.

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John Larkin         Highland Technology, Inc 
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Reply to
John Larkin

Speaking of 3KV, I got connected across that today. I was measuring the breakdown voltage of some SMA connectors (sadly, only about 1500 volts) and switched off my Kepco HV supply at 3KV. The meter dropped to zero, so I started taking the rig apart. The meter lies. Maybe the finger can be saved.

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John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  
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John Larkin

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