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I'm running a lot of simulations in LT-Spice, and I need someway to run them all either sequentially or at the same time.

I was going to use Python, but I'm not entirely clear on how I would get past the GUI and open the netlists I have and be able to run them all and collect the data I need.

Is there some easier way to run a large ammount of simulations at once?

As an example I have about 25 models that I need to run with various transistor model files that I reference in a library folder that I swap out for every iteration. I have 4 transistor nominal models that each have different speeds that need to be tested.

Any suggestions would be much appreciated.

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Does it need to be LT Spice? I believe the heart of SPICE is a command line tool. – dext0rb Jun 18 '14 at 18:12
This question appears to be off-topic because it is not about electronic design. – Leon Heller Jun 18 '14 at 18:18
@LeonHeller on WHAT planet is SPICE not a part of design? – placeholder Jun 18 '14 at 18:21
You'll find that Monte Carlo options are perfectly suited to this. You can Schmoo different parameters and it also can display the variations. LT-Spice MAY have disabled this by SPICE natively supports this. Start there – placeholder Jun 18 '14 at 18:23
Unfortunately for me, it does need to be LT-SPICE. Thank you for the Monte Carlo suggestion @placeholder – Metal_Rainbow Jun 18 '14 at 19:15
up vote 1 down vote accepted

If it just has to be LT Spice and you can't get past the GUI I would recommend the script program AutoIt. I've used it to automate some critical Windows applications which were lacking active-x-DDE-COM.dll-whatever. You can set it up to wait for files, push windows buttons, menuitems, call programs with arguments, etc.

Have a look at:



I would go for Winbatch if you want to pay for a script program.

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LTSpice can be run in batch mode with the -b command line switch.

From the LTSpice Help file:

-b: Run in batch mode. E.g. "scad3.exe -b deck.cir" will leave the data in file deck.raw

How to read and interpret the .raw output is left as an excercise for the reader.

Also note, among the command line switches:

-ascii: Use ASCII .raw files. Seriously degrades program performance.

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How exactly do I run it though? In command line mode that is. I'm not usually a windows user and have no idea how to do this on a windows machine. – Metal_Rainbow Jun 18 '14 at 20:56
I've never run it that way. You'll have to try it out for yourself. You can either open a command window ('cmd.exe' on the Start menu) or run it from whatever language you are using to sequence your tests. – The Photon Jun 18 '14 at 21:09

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