orcad pspice User Manual
Chapter B Convergence and “time step too small errors”
384
STEPGMIN
An alterative algorithm is GMIN stepping. This is not
obtained by default, and is enabled by specifying the
circuit analysis option STEPGMIN (either using .OPTION
STEPGMIN in the netlist, or by making the appropriate
choice from the Analysis/Setup/Options menu). When
enabled, the GMIN stepping algorithm is applied after the
circuit fails to converge with the power supplies at 100
percent, and if GMIN stepping also fails, the supplies are
then cut back to almost zero.
obtained by default, and is enabled by specifying the
circuit analysis option STEPGMIN (either using .OPTION
STEPGMIN in the netlist, or by making the appropriate
choice from the Analysis/Setup/Options menu). When
enabled, the GMIN stepping algorithm is applied after the
circuit fails to converge with the power supplies at 100
percent, and if GMIN stepping also fails, the supplies are
then cut back to almost zero.
GMIN stepping attempts to find a solution by starting the
repeating cycle with a large value of GMIN, initially
1.0e10 times the nominal value. If a solution is found at
this setting it then reduces GMIN by a factor of 10, and
tries again. This continues until either GMIN is back to the
nominal value, or a repeating cycle fails to converge. In
the latter case, GMIN is restored to the nominal value and
the power supplies are stepped.
repeating cycle with a large value of GMIN, initially
1.0e10 times the nominal value. If a solution is found at
this setting it then reduces GMIN by a factor of 10, and
tries again. This continues until either GMIN is back to the
nominal value, or a repeating cycle fails to converge. In
the latter case, GMIN is restored to the nominal value and
the power supplies are stepped.
Pspug.book Page 384 Wednesday, November 11, 1998 1:14 PM