Code Option Name Description Default Unit Recommendation
ABSTOL Absolute error tolerance Sets the absolute error tolerance. Default is suitable for most bipolar transistor VLSI circuits. 1.0e-12 A The default is suitable for low-power integrated circuits. If you are simulating power circuits and experiencing convergence problems or slow-run times, increase this value; very tight current tolerances are generally not required for these types of circuits. Values as high as1e-6A range are often acceptable.
VNTOL Voltage error tolerance Sets the absolute voltage error tolerance of the program. 1.0e-06 V The default is suitable for low-power integrated circuits. If you are simulating power circuits and experiencing convergence problems or slow-run times, increase this value; very tight voltage tolerances are generally not required for these types of circuits. Values as high as 1e-3V range are often acceptable.
CHGTOL Charge error tolerance Sets the charge tolerance in coulombs. 1.0e-14 C Do not change.
RELTOL Relative error tolerance Sets the relative error tolerance of the simulation, which is the universal accuracy control. The value can significantly affect the convergence of the solution and the simulation speed. Value must be between 1 and 0. 0.001 — If experiencing non-convergence, loosening the relative tolerance often helps. It is generally not advisable to increase this value above 0.01.
GMIN Minimum conductance Sets the minimum conductance used across junctions in semiconductor devices. 1.0e-12 mho Increasing this may positively improve the convergence of the solution, however, it will also negatively affect simulation accuracy.
PIVREL Minimum acceptable ratio of pivot Resets the relative value between the largest column entry in the matrix and an acceptable pivot value. Value must be between 1 and 0. 0.001 — If experiencing non-convergence, as an attempt of last resort, increase this value. High values (e.g., 0.9) have been found to help convergence.
PIVTOL Minimum acceptable ratio of pivot Sets the absolute minimum value for a matrix entry to be accepted as a pivot value. 1.0e-13 — Do not change.
TEMP Operating temperature Sets the temperature at which the entire circuit will be simulated. Many devices have characteristics that are functions of the operating temperature. 27 .C Use as needed.
RSHUNT Shunt resistance from analog nodes to ground Inserts a resistance from every analog node to ground. This is to eliminate Singular Matrix errors that result from a lack of DC path to ground and, in some cases, to assist convergence. No resistance inserted Ω Usually set to some very high resistance (say 1e+12 Ω, as lower values can be comparable to actual circuit impedances and affect the accuracy. For high impedance circuits, and circuits operating around resonant frequencies, it is recommended to completely remove RSHUNT.
RAMPTIME Transient analysis supply ramping time Sets ramping time for capacitor and inductor code models. 0 s Do not change.
CONVSTEP Fractional step allowed by code model inputs between iterations Controls automatic convergence assistance by establishing a relative step size limit in solving for the DC operating point. 0.25 — Do not change.
CONVABSSTEP Absolute step allowed by code model inputs between iterations Controls automatic convergence assistance by establishing an absolute step size limit in solving for the DC operating point. 0.1 — Do not change.
CONVLIMIT Enable convergence assistance on code models Enables/disables a convergence algorithm used in some built-in component models. — — Do not change.
ACCT Print simulation statistics Turns on/off the display of statistical data on simulation-related information. Data may be useful for debugging simulation-related problems. Data appears in the Grapher. — — Use as needed.
RAWFILEFORMAT Raw data file format

Applies to the design on a per analysis basis. You cannot switch between ASCII and Binary modes globally.

Binary files are much smaller in size, resulting in faster performance, including post processing.

 Binary — Use as needed.