.OPTIONS — Set Simulator Options

Keyword Default Description
abstol 1pA Absolute current error tolerance
allow_ambiguous_models false A model in use that has more than one definition is an error. This option turns such errors into warnings and makes LTspice keep going.
baudrate (none) Used for eye diagrams. Tells the waveform viewer how to wrap the abscissa time to overlay the bit transitions.
chgtol 10fC Absolute charge tolerance
cshunt 0. Optional capacitance added from every node to ground
cshuntintern cshunt Optional capacitance added from every device internal node to ground.
debugtran false When “debugtran” keyword is present (no value required), device and node convergence difficulty scores are added to the log file. Useful for troubleshooting convergence problems. Slows down the simulation. Results are relative, but generally, values below 1 are negligible, while values above ~50 are problematic.
defad 0. Default MOS drain diffusion area
defas 0. Default MOS source diffusion area
defl 100μm Default MOS channel length
defw 100μm Default MOS channel width
delay 0. Used for eye diagrams. Shifts the bit transitions in the diagram.
fastaccess false Convert to fastaccess file format at end of simulation.
flagloads false Flags external current sources as loads.
gfarad 1e-12 Conductivity leakage per farad of every capacitor element.
gfloat 1e-12 Conductivity added to from every floating node to ground if topology checking is enabled.
gmin 1e-12 Conductivity added to every PN junction to aid convergence.
gminsteps 25 Set to zero to prevent gminstepping for the initial DC solution.
gshunt 0. Optional conductance added from every node to ground.
itl1 100 DC iteration count limit.
itl2 50 DC transfer curve iteration count limit.
itl4 10 Transient analysis time point iteration count limit
itl6 25 Set to zero to prevent source stepping for the initial DC solution.
srcsteps 25 Alternative name for itl6.
list false Put expanded netlist into log file. This has priority over the corresponding choice in the Settings window.
logparams false Puts all parameters into the log file. Useful as a diagnostic.
logopinfo false Puts operating point information of semiconductor devices into log file.
maxclocks Infin. maximum number of clock cycles to save
maxstep Infin. Maximum step size for transient analysis
meascplxfmt bode Complex number format of .meas statement results. One of "polar", "cartesian", or "bode".
measdgt 6 Number of significant figures used for .measure statement output.
method trap Numerical integration method, either "trap", "modtrap", or "gear". This has priority over the corresponding choice in the Settings window.
minclocks 10 minimum number of clock cycles to save
mindeltagmin 1e-4 Limit for termination of adaptive gmin stepping.
no_caret_warning false Suppresses all caret operator warnings.
nomarch false Do not plot marching waveforms
noopiter false Go directly to gmin stepping.
numdgt 6 Historically "numdgt" was used to set the number of significant figures used for output data. In LTspice, if "numdgt" is set to be > 6, double precision is used for dependent variable data.
pivrel 1e-3 Relative ratio between the largest column entry and an acceptable pivot value.
pivtol 1e-13 Absolute minimum value for a matrix entry to be accepted as a pivot.
plotreltol .0025 Relative error tolerance for waveform compression.
plotvntol 10μV Absolute voltage error tolerance for waveform compression.
plotabstol 1nA Absolute current error tolerance for waveform compression.
plotwinsize 300 Number of data points to compress in one window. Set to zero to disable compression.
ptrantau .1 Characteristic source start-up time for a damped pseudo transient analysis to find the operating point. Set to zero to disable pseudo transient.
ptranmax 0 If set non-zero, that time of the damped pseudo transient analysis is used as the operating point whether the circuit has settled or not.
reject_number_tails false Report any numeric literal with additional text following the number as syntax error.
reltol .001 Relative error tolerance.
solver (none) Solver to use. One of "norm" or "alt". This has priority over the corresponding choice in the Settings window and the corresponding command line flag.
srcstepmethod 0 Which source stepping algorithm to start with.
sstol .001 Relative error for steady-state detection.
ststclocks 10 Number of clock cycles to process in continuous switching mode after steady state detection.
ststdelay 0 Time to wait before trying to detect steady state.
temp 27°C Default temperature for circuit element instances that don't specify temperature.
tnom 27°C Default temperature at which device parameters were measured for models that don't specify this temperature.
topologycheck 1 Set to zero to skip check for floating nodes, loops of voltage sources, and non-physical transformer winding topology
trtol 2.0 Transient error tolerance. This parameter is an estimate of the factor by which the actual truncation error is overestimated.
trytocompact 1 When non-zero, the simulator tries to condense LTRA transmission lines' history of input voltages and currents.
vntol 1μV Absolute voltage error tolerance.