Man Linux: Main Page and Category List


       gnucap - GNU Circuit Analysis Package


       gnucap [-b filename] [-i filename]


       GNUCAP  is  a general purpose circuit simulator.  It performs nonlinear
       dc and transient analyses, fourier analysis, and ac analysis linearized
       at an operating point.  It is fully interactive and command driven.  It
       can also be run in batch mode or as a server.  The output  is  produced
       as  it simulates.  Spice compatible models for the MOSFET (level 1,2,3)
       and diode are included in this release.

       Since it is fully interactive, it is possible to make changes  and  re-
       simulate  quickly.   The interactive design makes it well suited to the
       typical iterative design process used it optimizing a  circuit  design.
       It  is  also well suited to undergraduate teaching where Spice in batch
       mode can be quite intimidating.  This version, while  still  officially
       in  beta test, should be stable enough for basic undergraduate teaching
       and courses in MOS design, but not for bipolar design.

       In batch mode it is mostly Spice compatible, so it is often possible to
       use the same file for both GNUCAP and Spice.

       The  analog  simulation  is  based  on  traditional nodal analysis with
       iteration by Newton’s method and LU decomposition.  An event queue  and
       incremental  matrix update speed up the solution for large circuits (at
       some expense for small circuits).

       It also has digital devices for mixed signal simulation.   The  digital
       devices  may  be  implemented  as  either analog subcircuits or as true
       digital models.  The simulator will automatically  determine  which  to
       use.   Networks  of  digital  devices are simulated as digital, with no
       conversions to analog between gates.  This results in digital  circuits
       being  simulated  faster  than on a typical analog simulator, even with
       behavioral models.  The digital mode is experimental  and  needs  work.
       There will be substantial improvements in future releases.


       Two  command-line  options  are  available.  Only  one  of these may be
       specified. If no parameters are given, gnucap will start in interactive

       -b filename
              execute the commands in the named file then exit (batch mode)

       -i filename
              execute  the commands in the named file then go into interactive


       See /usr/share/doc/gnucap/bugs  for  a  list  of  known  bugs  in  this

       GNUCAP  is  an  ongoing  research  project.   It is being released in a
       preliminary phase in hopes that it will be useful and that others  will
       use  it  as  a thrust or base for their research.  I also hope for some
       comments that may help me direct my research.


       GNUCAP is being written by Albert Davis <>

       This manual  page  was  written  by  Jon  Rabone  <>  and
       maintained by Hamish Moffatt <> for the Debian package
       of  gnucap.    For   the   full   LaTeX   documentation,   please   see