Spice Stuff

Alan Robert Clark

Mar 15, 2002

Spice is a circuit simulator, extensively used Electronics I (and II) . Spice itself is free software developed by the University of California, Berkeley. It is a good olde fashioned ASCII-in ASCII-out program, using plain-text files. As such, it has been ported to about every computer platform known to man :-) However, most mouse junkies like a more geewhiz interface, and many companies have added all sorts of pre- and post-processors to Spice, as well as adding component libraries etc. The solution engine is still the same Spice code though. Not being too altruistic, these companies have limited the number of transistors/nodes that the unregistered versions can handle. There are several incarnations of these programs, with differing levels of capability and ``free-ness''. (BTW, A simple netsearch for ``Spice'' is a disaster!)

MicroSim offer a evaluation copy of PSpice 5.0, download it here, to which I have added the National Semiconductor range of component models. (Most component manufacturers have Spice models for their IC's, and offer them on their web pages) This is what the Spice book by Roberts and Sedra uses. This is version 2G6 of spice.

Rashid uses Version 6.1 of pspice, also limited in nodes etc. A **VERY** useful and complete reference manual is to be found on the Rashid CD in PDF form: /microsim/docs/pspcref.pdf. Don't print this, its 520 pages, use acroread, where the hypertext links are at least useful!!!!!

It appears that many do not know how to download :-), so:

To use the above software, Right-Click on the link ``download it here'', and open a Dos Box. Copy the file to a new directory (eg c:/apps/pspice), change to that directory, and type npspice, which will extract all the goodies. Then type demo which will extract pspice itself.

After running through the demo, you can simply run pspice filename.cir

A RedHat version of the full Berkeley Spice for linux which has unlimited functionality with a graphical post-processor (nutmeg) can be found here.

Use this as ``spice -r < circuit.cir'' which will create a ``rawspice.raw'' file with all voltages etc (similar to PSpice's probe command)

When you then run ``nutmeg'', it finds the raw output file, and you can plot what you like. Hit the man page (man nutmeg) for all the fancy things you can do. eg Any arithmetic operations including converting things to dB's etc. For a physical printout, remember to select postscript output. Then simply ``lpr postscript-file-name'' to get it printed.

NOTE THAT SPICE IS ALREADY INSTALLED ON BABBAGE!!!

A windows port of Spice3f4 can be found here.

A front-end written by a student is also available here.