it's a lot of time that a looking for a a model ltspice lm317 and lm337 made by the same hand.

Someone could kyndly tell me where I can find them?

Many thanks

Andrea

On Wed, Mar 19, 2025 at 04:21 PM, <andrea.patuelli@...> wrote:

it's a lot of time that a looking for a a model ltspice lm317 and lm337 made by the same hand.

Please tell us - why does it matter to you which individual person created a SPICE model?

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Many SPICE models do not identify the individual author(s) who created the model.? If you were to visit the website for a company such as Texas Instruments, they have thousands of SPICE models available for downloading.? Is it sufficient to know that the models were made by the engineering staff at T.I., or do you need somebody at Texas Instruments to provide you with the names and work schedules and internal emails for all their SPICE engineers so you can track down which people created which models on which dates?? What if a model passed through five people's hands on the way to being approved for publication?? Which individual person would you say had authored it?

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I think it's likely none of their models were written "from scratch" starting from the beginning.? They likely leverage off of previous work.? There might be 20 people who contributed to one model, over the course of 25 years.

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Anyway, I am wondering why does this matter?

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Is a SPICE model not good enough for you?

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Granted, SPICE models might not agree 100% with real parts.? Some are better than others, and a few are plain wrong.? Knowing the author won't help with that.? At the same time, two parts with the same part number likely won't agree with one another either.

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Also, I think your question "a model ltspice lm317 and lm337" is a bit too specific.? Do you want SPICE models (which therefore run on LTspice), or do you really require an encrypted or binary LTspice model which runs only on LTspice?? I could be wrong, but as far as I know neither LTC nor ADI made the LM317 or LM337, therefore they would not have made LTspice models for them.? They did make enhanced (competing) products, named LT317 and LT337 - but those are not what you asked about.

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National Semiconductor designed the LM317 and LM337, and NSC became part of TI, and TI's preferred simulators are PSpice (which is SPICE) and TINA-TI (which can use SPICE models as well as its own).? When TI makes SPICE models for their parts, they call them "PSpice" even when they are generic SPICE.? The majority of them run on LTspice with no changes, but a few might need some syntax tweaks.

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Someone could kyndly tell me where I can find them?

FYI -

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The non-encrypted models (thus usable by LTspice) for T.I.'s LM317 and LM337 BOTH claim to have been designed by:

? ??** Released by: WEBENCH Design Center, Texas Instruments Inc.

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Neither model lists the individual person or people responsible for making them.? You could call up T.I. and ask them - but I think they are unlikely to tell you.

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Andy

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Hi Andy, hi John, thanks for your time .
My ask was only for find two model with the same graphic symbol, the same electrical comportament, and the same kind of installation.
I'm a newbie and sometime i find .lib, .sub, .model , .asy, .test, ecc. and is not easy to understand what i need for import a good model. I learned that usually I need ?a .sub and .asy file to put in Sym and Sub folder.
Another trouble on my way is that I found an common author (Roberto Scaramuzzino) for both on this site, but give me an error about "missing loading lib UniversalOpamps2". I cecked on web and It seams a problem of release in use (my release is 17.1.9)

I'm building a Dual rail power supply , and loading two models (317-337) founds on this site, ?I read different Volts output values at the same point LM317-LM337 (24,4V-25,4V), putting the same input voltage but with sign different (+35V,-35V).
So I can understand that is not a easy work for a newbee? but I want learn from the best ;-)

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Here my scheme:

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Many thanks

Andrea

On Thu, Mar 20, 2025 at 02:23 PM, <andrea.patuelli@...> wrote:

Hi Andy, hi John, thanks for your time .
My ask was only for find two model with the same graphic symbol, the same electrical comportament, and the same kind of installation.

As you might know already, the schematic symbol is not part of the SPICE model, and it has no real meaning.? You can draw and modify the symbols without changing the results of the simulation.? Let me emphasize again, that you can draw those symbols yourself.

I'm a newbie and sometime i find .lib, .sub, .model , .asy, .test, ecc. and is not easy to understand what i need for import a good model.

LTspice just needs a SPICE model for the component.? The filename's extension (.lib, .sub, .mod, .model, .txt, etc.) does not make any difference.? It just needs to be a SPICE model inside the file.

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The schematic symbol is a .asy file.? You can create one yourself, or you can borrow one from another component that is similar.

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Another trouble on my way is that I found an common author (Roberto Scaramuzzino) for both on this site, but give me an error about "missing loading lib UniversalOpamps2".

There are many mistakes that could have caused that error.? It might be simple.? Without seeing your files (the .asc schematic file, and all .asy symbol and model files), we can only guess what the problem might be.? If the schematic attempted to load the library file "UniversalOpamp2.lib" but looked like this:

? ? .lib UniversalOpamp2

then the problem was using the wrong filename.? "UniversalOpamp2" is not the same filename as "UniversalOpamp2.lib".

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I cecked on web and It seams a problem of release in use (my release is 17.1.9)

Probably not.? But do not believe most things you find on the web.? They are often wrong.

Here my scheme:

DualRailPS

As you know, pictures of your schematics do not help anyone.? If you want assistance with your schematics, you must upload the schematic file itself plus all symbol files and all SPICE model files that did not come with LTspice itself.? But do not include the .RAW or .LOG files!? Zip the needed files into one .ZIP file, then upload that .ZIP file to the Temp folder under Files.? Then write another message telling us that you did it.

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Andy

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