cgs@umd5.UUCP (02/18/87)
Can anyone steer me to references, or can explain the general principles used in the "Spice" program to calculate solutions of arbitrary circuits? That is, what sort of abstract models/algorithms are used so the program can analyze circuits? I'm not asking how a person goes about analyzing a circuit, I'm asking how does one program a computer to do it for such wide varieties and levels of complication that Spice calculates? Programming a computer to analyze specific, predetermined topologies is not the same thing as Spice, either. I'm asking you folks on behalf of my immediate employer for the purposes of his continued education (and my own as well), in case anyone wants to know. ad-thanks-vance! -- --==---==---==-- .. The jaws that bite, the claws that catch! .. ARPA: cgs@umd5.UMD.EDU BITNET: cgs%umd5@umd2 UUCP: ..!seismo!umd5.umd.edu!cgs
ken@rochester.UUCP (02/19/87)
I'm trying hard to remember what they taught me as an EE. Any EE worth his salt can tell you that the analysis of circuits can done by replacing the circuit components with the equivalent mesh of resistances, impedances, generators, etc. For DC you must use the DC equivalent. For AC you must use the appropriate model for the frequencies you are working at. Then you formulate the mesh as a system of linear equations, and solve. The linearity assumption is important. If this doesn't hold well, you must use better models. I'm not saying this is the way it is done in Spice, but it is one general approach. I leave advanced comments for those who know better. Check your local engineering library for books on Computer Analysis of Circuits. I remember books on ECAP and other venerable programs. I'm sure the literature has been updated since then. Ken
keithl@vice.UUCP (02/20/87)
In article <1450@umd5>, cgs@umd5 (Chris Sylvain) writes: > Can anyone steer me to references, or can explain the general principles > used in the "Spice" program to calculate solutions of arbitrary circuits? > That is, what sort of abstract models/algorithms are used so the program > can analyze circuits? Call the publications office of the Electronics Research Lab at UC Berkeley, where Spice was developed under Dr. Don Pederson. They probably still have some copies of the reports that describe how Spice works. They can probably also point you at some of the early thesis work that went into Spice. -- Keith Lofstrom MS 59-316, Tektronix, PO 500, Beaverton OR 97077 (503)-627-4052
klein@gravity.UUCP (02/20/87)
In article <1450@umd5>, cgs@umd5 (Chris Sylvain) writes: > Can anyone steer me to references, or can explain the general principles > used in the "Spice" program to calculate solutions of arbitrary circuits? Possibly the best reference on SPICE and its algorithms is Larry Nagel's PhD thesis, available from UC Berkeley's Electronics Research Lab: SPICE2: A Computer Program to SImulate Semiconductor Circuits Lawrence W. Nagel Memorandom No. ERL-M520 May 9, 1975. -- Mike Klein klein@sun.{arpa,com} Sun Microsystems, Inc. {ucbvax,hplabs,ihnp4,seismo}!sun!klein Mountain View, CA