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LTspice models do not work in Qspice
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On Sat, Apr 19, 2025 at 06:09 AM, suded emmanuel wrote:
It is not.? Did you upload the wrong files?? There is no "PROP_DELAY" anywhere in the model you uploaded.? It is definitely not in the first line, which looks like this:
Please be more careful about what you uploaded.
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Andy
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On Sat, Apr 19, 2025 at 06:16 AM, suded emmanuel wrote:
Hmm.? I wonder if you uploaded it to the wrong group? ?
This group is at /g/LTspice and files should go into /g/LTspice/files/Temp.? You have not uploaded anything here since before your message # 159934, which was 6 hours ago.? It was the file with the missing LTspice symbol (and maybe other missing things too).
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Andy
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I am wondering about one thing.
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TI's SPICE model for the UCC27282 is structured as a series of several subcircuits, which are not nested.? For example, it starts with the UCC2722 subcircuit, and then after that there is another subcircuit named "falling_delay", then "d_d1", and so on for the rest of the model file.? This is normal SPICE syntax and it ought to work in any SPICE program.? I don't like doing it that way because you end up with perhaps dozens of subcircuit definitions, which might conflict with others that you used in the same simulation.? (Say, if you had another model for a device named "Falling_Delay" in the same simulation.? It would conflict.)? I count 49 separate subcircuits in this file!
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I call that sloppy.
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I prefer wrapping ALL of them inside the main UCC27282 subcircuit.? That is called a "nested subcircuit definition", and I think all SPICE programs support it.? It is safer because it isolates the names so that conflicts won't happen.? (To make TI's model like that, find the first .ENDS command and move it to the very end of the model file.)
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If, by some strange chance, QSPICE imports the model file "UCC27282 model.txt" by taking only the UCC2722 subcircuit and ignoring the other 48 subcircuits, that would be a problem.? It would not find any of the other subcircuit definitions, and you'd get errors.
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If I remember correctly, there is a way (in some SPICE programs) to make it open a library file but load only one requested model (subcircuit) from inside that file, ignoring everything else.? If that happened, then the simulation wouldn't find all of the subordinate subcircuits.
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LTspice does not work that way.? I wonder if QSPICE does.? That would make it incompatible with most PSpice models from TI.
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Andy
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Hi Andy,
Usually most TI models work well with LTspice, I hardly had issues with them, there was something i diidnt do in Qspice when I imported the model I had to tick a box "include all files", but even with that I had a bunch of errors that prevented running the simulation (with regards to UCC27282)!
I posted to Qspice forum and awaiting a reply, if I get a solution I will message here
I will try moving the End command!
Many thanks
Suded |
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Hello, you have to organize the directory by creation date and your file should be listed on the top.
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On Sat, Apr 19, 2025 at 04:50 PM, suded emmanuel wrote:
It looks like you had only one file to include (UCC27282 model.txt), so it is not likely that command or button does anything differently.? Did your simulation require more files than that in LTspice? ?
Andy
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On Sat, Apr 19, 2025 at 05:12 PM, suded emmanuel wrote:
That is true, because you did not upload it yet!? You won't see it online until you upload it. ?
It appears you uploaded just the schematic file again ("Synchronous Buck Boost 1 Converter using UCC27282 driver.asc"), a couple of hours ago.? But you uploaded the same exact schematic already, much earlier in the day, inside your .zip file, so the new schematic is a rehash with nothing new.
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And it is still missing the LTspice symbol file, "UCC27282.asy", because you have not uploaded it yet!
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Without that file, we can not open your schematic in LTspice.? There might be things hidden in that file that we can't see without it.? I am especially interested to see why you got some of the errors you said you had, when there was nothing apparent on the schematic or in TI's model file that had one of those subcircuits.
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Unfortunately I do not know about importing models into QSPICE.? I am sure it must have a way to do it.
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Andy
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Reason for button click "include all files", I was looking into Qspice forum, in one thread Mike suggested that this button should be ticked, which I tried for another model for TLV1831 comparator, and only when i ticked this box the model/simulation worked in Qspice, so I thought I do the? same for UCC27282 but that didnt work and it gave whole bunch of errors like:
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Ignoring shorted resistor: "RSDUM?XNSW1?X_U1_U11?X1"
Warning: Unresolved parameter: "RONVAL" GOUT: Trouble evaluating "" for I. Warning: Unresolved parameter: "RONVAL" ?
"RONVAL" is in the .SUBCKT file
but for TLV1831 simulation worked smoothly!
Regards,
Suded |
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On Sat, Apr 19, 2025 at 08:05 PM, suded emmanuel wrote:
There is no IRFR7446 on your schematic.? I think you did not need to "upload" (? - did you mean "include"?) that model file. Did you mean the BSZ076N06NS3 MOSFET? ?
Let me back up here.
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Are we even talking about the same schematic, the same circuit?? You have told us about error messages which could not have come from your schematic because they did not have those devices.? Now you're saying there are MOSFETs that were not on your schematic.
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Maybe you can explain what you are actually doing?
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Andy
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Hi Andy,
Yes, I replaced it with IRFR7446 in Qspice, since ?BSZ076N06NS3 is built in LTspice only, IRFR7446 should do the same job
By the way Temp was preventing me from uploading the same file name it says it already has it, so i changed the name to Buck Boost only and uploaded it, it took it so it should be there!
Regards,
Suded |
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Suded,
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Thank you for the new upload.? It has all the pieces, for LTspice at least.
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It does have 2 problems, though, both of which are fixable on our end:
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Is there any chance that "ucc27282.lib" and "UCC27282 model.lib" are not the same?
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Andy
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I can't see much reason for the simulation going bad in QSPICE.
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But I am not currently running QSPICE, and I do not know the steps it uses to import a model - or, more precisely, to create a schematic symbol for a new part, since that should be all it needs to do.? The UCC27282 is a SPICE model already so it should not need to be modified or converted.
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Mind you, LTspice spits out several warnings and errors, about curly braces and undefined symbols.? Those are usually caused by doubled-up { { curly braces } } in many of TI's models.? They are improper in LTspice, but I think we can ignore those messages.? Also there are a lot of warnings about "empty" pin currents, which can be ignored.? And the circuit simulates rather slowly.
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I am assuming that "PROP_DELAY" error was from a different simulation because that text is totally absent from this one.
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But the "COMPHYS_BASIC_GEN" errors could have come from this model.? I think it should not have, if QSPICE used the full ucc27282.lib model file, but maybe there is a reason why it does not.? I wonder if there is a setting in QSPICE for that.? I think the PARAMs are OK.? That's all I can say.
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Andy
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Hi Andy,
Many thanks for that, Im trying to get something on the Qspice forum as we speak, they said there are errors that could be ignored, but in my case the waveform window is not showing up, they sent me an example but still not running with errors and the waveform window not showing up!
Regards,
Suded |
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