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Recently I have downloaded a model from Toshiba's web site and tried to create a simple circuit like in the image below.

Simulated circuit

The signal on the "V(n002)" point wasn't like I expect. After that, I found out that there is another model file which comes with LTSpice. I tried that also and it works as I expected. Both simulation outputs can be seen in the images.

I am not able to do a comparison between both models , because the one from LTSpice is encrpted so there is no way to inspect the model.

At this point, I just would like to ask what might be the problem with the model which comes directly from Toshiba.

Any help is appreciated


LTSpice model local path: Program Files\LTC\LTspiceXVII\lib\sub\Contrib\Toshiba\pmos\SSM3J56MFV.lib

Toshiba model web link:


Toshiba model output LTSpice model output

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  • \$\begingroup\$ LTSpice doesn't normally encrypt models as far as I know --> the one from LTSpice is encrpted \$\endgroup\$
    – Andy aka
    Jan 19, 2023 at 10:37
  • \$\begingroup\$ ...Contrib\Toshiba\pmos\SSM3J56MFV.lib this model file seems enrypted in my computer. When I open it in a file editor there is nothing readable. \$\endgroup\$
    – swer
    Jan 19, 2023 at 12:34
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    \$\begingroup\$ You have the one from Toshiba's website connected incorrectly. SPICE pin order for MOSFETs is D G S. You have it connected as G S D. In other words, pin 1 on your symbol should be D, pin 2 should be G, and pin 3 should be S. Fix that. \$\endgroup\$
    – Ste Kulov
    Jan 19, 2023 at 21:01
  • \$\begingroup\$ Thank you Ste. I didn't know that. It works properly now. \$\endgroup\$
    – swer
    Jan 20, 2023 at 8:04
  • \$\begingroup\$ Here's a reference so you can avoid using that generic box symbol with subcircuit MOSFETs. analog.com/en/technical-articles/… \$\endgroup\$
    – Ste Kulov
    Jan 20, 2023 at 15:01

1 Answer 1

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You have the one from Toshiba's website connected incorrectly. SPICE pin ordering for MOSFETs is D G S. You have it connected as G S D. In other words, pin 1 on your symbol should be D, pin 2 should be G, and pin 3 should be S. When in doubt of what the pin order for a particular symbol is, you can always CTRL+rightclick it and click the "Open Symbol" button. Then rightclick each pin to see its "Netlist Order"

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Here's a reference so you can avoid using that generic box symbol with subcircuit MOSFETs: https://www.analog.com/en/technical-articles/ltspice-using-an-intrinsic-symbol-for-a-third-party-model.html

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