Re: LTspice models do not work in Qspice
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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Re: LTspice models do not work in Qspice
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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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 06:16 AM, suded emmanuel wrote:
Just uploaded the .zip file containing the symbol
Hmm.? I wonder if you uploaded it to the wrong group?
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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). ?
Andy
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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 06:16 AM, suded emmanuel wrote:
Just uploaded the .zip file containing the symbol
Um, no.? You did not.
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Please upload it.
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Andy
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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 06:09 AM, suded emmanuel wrote:
"PROR_DELAY " is a line written in the model I uploaded, if you look from the 1st line you can see it, Qspice is objecting to this syntax!
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:
* * source UCC27282
Please be more careful about what you uploaded.
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Andy
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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 05:54 AM, suded emmanuel wrote:
Sorry, I will now and reupload
That has not happened yet.
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Did you forget to upload the correct version of your LTspice simulation, with the missing symbol?
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Andy
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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 06:15 AM, suded emmanuel wrote:
Sorry again Qspice objecting to the following line:
COMPHYS_BASIC_GEN
In what way is it "objecting" to that line?
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Why do you have that line in your simulation?? Is that the name of a capacitor?? It starts with a C so it must be.? Is it a comment line that you forgot to make into a comment?
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These snippets about errors are not very helpful without more context.
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Andy
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Re: LTspice models do not work in Qspice
On Sat, Apr 19, 2025 at 04:24 AM, suded emmanuel wrote:
For example I have the following error:
No such subcircuit: PROP_DELAY
I have "PROP_DELAY " in the 1st line of the .subckt model
If you have that kind of error, it means you forgot to include the subcircuit whose name is "PROP_DELAY".? That would almost definitely be a subcircuit that you made, and that you called from your schematic, which you forgot to include in the QSPICE simulation.
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Having "PROP_DELAY" in the 1st line of a .subckt model is meaningless.? Why not tell us EXACTLY what that line looked like?? Also, check to see how that subcircuit is imported into the simulation - or more likely, not imported into it, since that seems to be the problem.
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On this basis, I'd say this has nothing to do with compatibility of models in QSPICE.? You simply forgot to load or include the model.
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Andy
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Re: LTspice models do not work in Qspice
Hi Tony,
Many thanks for your reply
I will do the changes you suggested and see if it works
Thanks again
Suded
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Re: LTspice models do not work in Qspice
On 19/04/2025 13:00, suded emmanuel via
groups.io wrote:
In the example I uploaded I used BSZ076N06NS3 N-ch MOSFET?
But in Qspice I used IRFR7446 mosfet which I generated the
model for in Qspice that is all good, but I think the error is
with regards to the UCC27282 model and not the mosfet!
Anyway the uploaded .zip file should work in LTspice, but
Qspice is giving me an error:
Fatal error: No such subcircuit: COMPHYS_BASIC_GEN
"COMPHYS_BASIC_GEN" is the 4th line written in the model
after ".SUBCKT" command line, could it be the format (sytntax)
needs to be written differently?
The reason why I want to run the Qspice simulation to see it
simulates faster than LTspice!?
Well, we can't run it because you have not uploaded the
missing/changed files.
The syntax for COMPHYS_BASIC_GEN seems normal. Many TI models use a
similar methodology - they are often made using the PSpice model
tool, and they normally work OK in LTspice.
The only thing I wonder is whether the PARAMS: VDD=1 VSS=0
VTHRESH=0.5 syntax is accepted in QSPICE. But since I don't use
QSPICE, I couldn't test it, anyway.
Perhaps you could try changing it from:
.SUBCKT COMPHYS_BASIC_GEN INP INM HYS OUT PARAMS: VDD=1 VSS=0
VTHRESH=0.5
..
..
..to:
.SUBCKT COMPHYS_BASIC_GEN INP INM HYS OUT
.PARAM VDD 1
.PARAM VSS 0
.PARAM VTHRESH 0.5
..
..
If that works, I guess it will then throw up similar errors in turn
for all the other .subckts that use the same syntax - they will need
the same fix.
If that does doesn't work, I give up. I suggest you ask for help
from the QSPICE forum. Similar compatibility questions have been
asked there before, right from day one. You can't reasonably expect
much help for QSPICE from a group "dedicated to LTspice".
--
Regards,
Tony
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Re: LTspice models do not work in Qspice
Hi Tony,
In the example I uploaded I used BSZ076N06NS3 N-ch MOSFET?
But in Qspice I used IRFR7446 mosfet which I generated the model for in Qspice that is all good, but I think the error is with regards to the UCC27282 model and not the mosfet!
Anyway the uploaded .zip file should work in LTspice, but Qspice is giving me an error:
Fatal error: No such subcircuit: COMPHYS_BASIC_GEN
"COMPHYS_BASIC_GEN" is the 4th line written in the model after ".SUBCKT" command line, could it be the format (sytntax) needs to be written differently?
The reason why I want to run the Qspice simulation to see it simulates faster than LTspice!?
Regards,
Suded
?
?
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Re: LTspice models do not work in Qspice
Just uploaded the .zip file containing the symbol
Suded
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Re: LTspice models do not work in Qspice
Hi Tony,
Sorry again Qspice objecting to the following line:
COMPHYS_BASIC_GEN
Its written in the model I uploaded
I found the symbol I will upload again
Suded
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Re: LTspice models do not work in Qspice
Hi Tony,
"PROR_DELAY " is a line written in the model I uploaded, if you look from the 1st line you can see it, Qspice is objecting to this syntax!
Regards,
Suded
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Re: LTspice models do not work in Qspice
Hi Tony,
Sorry, I will now and reupload
Suded
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Re: LTspice models do not work in Qspice
On 19/04/2025 11:29, suded emmanuel via
groups.io wrote:
Many thanks, I've just uploaded the .ZIP file to temp:
Example
Buck Boost for upload to group.zip
Please
let me know if all is good
It
contains the .asc file and the UCC27282 model as a .subckt
UCC27282 symbol is missing. According to your schematic file, it is
in your "AutoGenerated" folder. You should copy that to the
schematic folder, and edit the symbol ModelFile attribute to remove
the hard-coded path.
However I can see in your schematic that you have used "standard"
LTspice VDMOS models. As I said previously, these are not portable.
I also don't see .subckt PROP_DELAY. Did you upload the wrong file?
--
Regards,
Tony
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Re: LTspice models do not work in Qspice
Hi Tony,
Many thanks, I've just uploaded the .ZIP file to temp:
Example Buck Boost for upload to group.zip
Please let me know if all is good
It contains the .asc file and the UCC27282 model as a .subckt
Suded
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Re: LTspice models do not work in Qspice
The QSPICE group is currently locked. The Qorvo website has some QSPICE support resources which may provide an answer to your question.
On Sat, Apr 19, 2025 at 04:35 Tony Casey via <antoniustrevorum= [email protected]> wrote:
On 19/04/2025 10:20, suded emmanuel via
wrote:
I have models (.suckt) that are working perfectly in LTspice,
when I import them in Qspice they dont work
Does Qspice use a different syntax?
Most (SPICE) simulators use the same general syntax, but all or most
simulators have features that are not supported in all the others.
Some features in LTspice are proprietary and hence not available in
other simulators.
Examples of uniqueness include VDMOS models and anything that uses
an A-device, like UniversalOpamps or logic gates. There may also be
a few functions that are not portable. However, unless you disclose
which models you are referring to, it's not possible to comment
further.
If you're wanting to use QSPICE, perhaps you should ask in a QSPICE
group. Perhaps it has an LTspice to QSPICE converter, I don't know.
--
Regards,
Tony
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Re: LTspice models do not work in Qspice
On 19/04/2025 10:46, suded emmanuel via
groups.io wrote:
Can I upload the
.subckt file?
Of course. Go to Files
> Temp and click on the New/Upload button.
It would also be helpful if you could also provide a schematic that
(successfully) uses the .subckt, and any other files that are not
provided with LTspice. Put them in a zip, and upload that.
Don't forget to send another message if/when you do that.
--
Regards,
Tony
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Re: LTspice models do not work in Qspice
Can I upload the .subckt file?
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Tony Casey