Nonlinear resistors can be generated by putting the expression directly on the element. The expressions may be any function of voltages and currents through voltage sources in the system. In an AC analysis, only the DC component of a voltage or current source when the initial operating point was calculated is used. In a transient analysis, any voltages or currents are evaluated at each time point.

To reference in an expression the voltage at a node in your circuit, you must first name the node in the schematic using a Net Label. You then use the name defined in the Net field of the Net Label's properties to reference the node using the following syntax:

V(Net1) : The voltage at the node Net1 relative to the ground node.
V(Net1,Net2) : The voltage difference between nodes Net1 and Net2.

To reference in an expression the currents through voltage sources, you must first list the sources in the VSRC parameter. You then use the name I1 to refer to the first generator in the list, I2 to refer to the second etc..

You can specify the name of the generator directly in the expression using the following syntax:

I(Vsrc) : The current flowing in the independent voltage source Vsrc.


Parameter Description
Value Expression defining the resistance. This value is used only if the EXPR parameter is not specified.
EXPR Expression defining the resistance. If omitted, the value specified in the component VALUE is used.
VSRC Specifies the list of independent voltage sources through which the control currents flow. The names of the individual generators must be separated by a space character. The component accepts up to a maximum of 5 generators. I1 in the expression must be used to refer to the first control current (first generator specified in the parameter VSRC), I2 to refer to the second current control etc.