Most simple circuit elements typically require only a few parameter values. However, some devices (semiconductor devices in particular) that are included in SPICE require many parameter values. Often, many devices in a circuit are defined by the same set of device model parameters. For these reasons, a set of device model parameters is defined on a separate .MODEL line and assigned a unique model name. The device element lines in SPICE then refer to the model name. The general form is:

MODEL <model name> <model type> [<param> = <value>]*

model name: The model name which is used to reference a particular model.

model type

Specifies the type of model. Devices can only reference models of a corresponding type. Must be one of the types outlined in the table that follows:

Element	Description	Model type	Description
A	XSPICE device	XSPICE model	XSPICE code model
C	Capacitor	CAP	SPICE3 Capacitor model PSPICE Capacitor model
D	Diode	D	Diode model
L	Inductor	IND	Inductor model
J	JFET	PJN NJF	P-channel JFET model N-channel JFET model
M	MOSFET	PMOS NMOS	P-channel MOSFET model N-channel MOSFET model
O	BJT	PNP NPN	PNP BJT model NPN BJT model
R	Resistor	R RES	SPICE3 Resistor model PSPICE Resistor model
S	Voltage controlled switch	SW VSWITCH	SPICE3 Voltage controlled switch PSPICE Voltage controlled switch
U	Uniform distributed RC	URC	Uniform distributed RC model
W	Current controlled switch	ISWITCH	SPICE3 Current controlled switch PSPICE Current controlled switch
X	Subcircuit model	Subcircuit name	Model defined by the user
Z	MESFET	PMF NMF	P-channel MESFET model N-channel MESFET model

param=value: Parameter values are defined by appending the parameter name followed by an equal sign and the parameter value. Model parameters that are not given a value are assigned the default values. The name must begin with an alphabetic character. The value can be a constant value or a numeric expression. The expressions must be enclosed in braces.

Examples

.MODEL QDEFAULT NPN
.MODEL QMOD PNP ( BF=80 )
.MODEL MURC URC RPERL=50 CPERL=5pF
.MODEL AMP GAIN(gain=5.0)
.MODEL NAND1 D_NAND (RISE_DELAY=0.1 FALL_DELAY=0.2)

Examples

See also