.OPTIONS -- Set Simulator Options

 

Keyword

Data Type

Default Value

Description

abstol

Num.

1pA

Absolute current error tolerance

baudrate

Num.

(none)

Used for eye diagrams. Tells the waveform viewer how to wrap the abscissa time to overlay the bit transitions.

chgtol

Num.

10fC

Absolute charge tolerance

cshunt

Num.

0.

Optional capacitance added from every node to ground

cshuntintern

Num.

cshunt

Optional capacitance added from every device internal node to ground.

defad

Num.

0.

Default MOS drain diffusion area

defas

Num.

0.

Default MOS source diffusion area

defl

Num.

100µm

Default MOS channel length

defw

Num.

100µm

Default MOS channel width

delay

Num.

0.

Used for eye diagrams. Shifts the bit transitions in the diagram.

fastaccess

flag

false

Convert to fastaccess file format at end of simulation.

flagloads

flag

false

Flags external current sources as loads.

Gmin

Num.

1e-12

Conductance added to every PN junction to aid convergence.

gminsteps

Num.

25

Set to zero to prevent gminstepping for the initial DC solution.

gshunt

Num.

0.

Optional conductance added from every node to ground.

itl1

Num.

100

DC iteration count limit.

itl2

Num.

50

DC transfer curve iteration count limit.

itl4

Num.

10

Transient analysis time point iteration count limit

itl6

Num.

25

Set to zero to prevent source stepping for the initial DC solution.

srcsteps

Num.

25

Alternative name for itl6.

maxclocks

Num.

Infin.

maximum number of clock cycles to save

maxstep

Num.

Infin.

Maximum step size for transient analysis

meascplxfmt

string

bode

Complex number format of .meas statement results. One of "polar", "cartesian", or "bode".

measdgt

Num.

6

Number of significant figures used for .measure statement output.

method

string

trap

Numerical integration method, either trapezoidal or Gear

minclocks

Num.

10

minimum number of clock cycles to save

MinDeltaGmin

Num.

1e-4

Sets a limit for termination of adaptive gmin stepping.

nomarch

flag

false

Do not plot marching waveforms

noopiter

flag

false

Go directly to gmin stepping.

numdgt

Num.

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

Num.

1e-3

Relative ratio between the largest column entry and an acceptable pivot value.

pivtol

Num.

1e-13

Absolute minimum value for a matrix entry to be accepted as a pivot.

reltol

Num.

.001

Relative error tolerance.

srcstepmethod

Num.

0

Which source stepping algorithm to start with.

sstol

Num.

.001

Relative error for steady-state detection.

startclocks

Num.

5

Number of clock cycles to wait before looking for steady state.

temp

Num.

27ºC

Default temperature for circuit element instances that don't specify temperature.

tnom

Num.

27ºC

Default temperature at which device parameters were measured for models that don't specify this temperature.

topologycheck

Num.

1

Set to zero to skip check for floating nodes, loops of voltage sources, and non-physical transformer winding topology

trtol

Num.

1.0

Set the transient error tolerance. This parameter is an estimate of the factor by which the actual truncation error is overestimated.

trytocompact

Num.

1

When non-zero, the simulator tries to condense LTRA transmission lines' history of input voltages and currents.

vntol

Num.

1µV

Sets the absolute voltage error tolerance.

plotreltol

Num.

.0025

Sets the relative error tolerance for waveform compression.

plotvntol

Num.

10µV

Sets the absolute voltage error tolerance for waveform compression.

plotabstol

Num.

1nA

Sets the absolute current error tolerance for waveform compression.

plotwinsize

Num.

300

Number of data points to compress in one window. Set to zero to disable compression.

ptrantau

Num.

.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

Num.

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.