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Simulation: add visually coherent symbols for BJTs

Matthias Rabault requested to merge mrabault/kicad-symbols:spice_bjt into master

Hi,

This adds two symbols to Simulation_SPICE: a NPN and a PNP, both with substrate:

27-09-2021_2032

I find the pspice BJT symbols quite unsightly. They clash with the "normal" KiCAD BJT style, while also not even being visually coherent with one another: the arrows don't have the same dimensions. Having clean-looking symbols for simulation could also make KiCAD look more convincing for simulation in the eyes of new users, especially companies.

The substrate pin being too close to the transistor base is, IMHO again, confusing. Its proposed placement was inspired by these symbols.

I want to stress that I'm not an IC designer by any means, and hence perhaps missed an industry de facto standard for BJTs with substrate pins. If there are any, please correct me.

According to check_symbol.py, my proposed symbols violate rules S3.1 and S5.2.

  • S3.1 is violated because symbol origins are slightly off-center, but that's also the case with Q_NPN_BCE and the PNP equivalent.
  • S5.2 is violated because I didn't specify any footprint filter, what should I do there ? Leave it as-is ?

Cheers,
Matthias

  • Provide a URL to a datasheet for the symbol(s) you are contributing [irrelevant]
  • An example screenshot image is very helpful
  • Ensure that the associated footprints match the official footprint library [irrelevant]
    • A new fitting footprint must be submitted if the library does not yet contain one.
  • If there are matching footprint PRs, provide link(s) as appropriate [irrelevant]
  • Check the output of the automated check scripts - fix any errors as required
  • Give a reason behind any intentional library convention rule violation.
Edited by Matthias Rabault

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