Reusing and storing standard symbols for .subckt defined models

QSPICE
1

I really, really want to switch from LTspice to QSPICE. However the lack of explicit documentation is making it very difficult.

There is a rumor how importing 3rd party libraries is now made seamless, but I do not feel that way.

Assume that I am given BJT model not as .model but as .subckt with arbitrary pin order. In LTspice, I copied the *.asy file for bjt, and with arbitrary pin order of that one particular symbol I assigned to this symbol that subckt as ‘X’ together with linked path to the subckt. Later I could seamlessly use that symbol as is.

I cannot find a way how to do the similar in QSPICE. Every tutorial I found was only on importing .model which is indeed trivial. Other tutorials on imporiting opamps as .subckt always ended with drawing an arbitrary triangle. Am I really supposed to redraw symbol every time I import model/subckt? How can I organize my own library of symbols so that i can reuse them. I am willing to redraw all my exisitng schematics I have in LTspice, but I am definitely not willing to draw every symbol every time as this would lead to incosistencies and totally useless work I guess. Call me lazy, but there must be a library of standard symbols like Zener, Schottky, BJT, OpAmp such that I can seamlessly assign my subckt/model to them. Could you please navigate me how to do it?

In LTspice I always had for large project copy of lib folder containg cmp/sym/sub with my customized parts. This was part of search paths so I could easily work with it and could also be easy to share with anyone. How is this solved in QSPICE?

2

You can take a look at whether my unofficial guide can be helpful on my GitHub. The guideline “Qspice - General Reference Guide by KSKelvin.pdf (in the Guideline directory)” has section focus on subckt symbols. (you can download the guide in pdf format in Github)

I have created various subckt symbols which can be found in the directory: Symbols/subckt symbol (third-party model)/. If any subckt symbols are missing, feel free to let me know. By the way, you can easily convert a standard Qspice symbol for use with .subckt, if it is just a simple native device. Refer to the General Guideline, Section Part 2D for an example.

3

You have multiple questions, and I am not quite sure where to begin. The short answer is that in Qspice, you can use a generic symbol. As long as your .subckt library file (.lib, .txt, etc.) is added to the Symbol Directory in the “Symbol & IP Browser,” Qspice can search its sub-folders for library files. Therefore, I can manage everything within the same folder—all symbols and all libraries—as long as I add the root directory there.

Refer to Part 2C in the General Reference Guide for this discussion.

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4

Thank you very much for such an extensive materials. Excellent. Can’t tell you at the moment as I need some time to fully get into it. I might come later. Looks fantastic