res_var :
A variable resistor circuit element.
The res_var
primitive represents a two-terminal resistor of which resistance varies with the voltage across the two terminals, pos
and neg
.
The parameter R
is a real-typed array defining the voltage-dependent resistance as a piecewise-constant (PWC) function using the following coefficients:
'{R0, V1, R1, V2, R2, V3, R3, ..., RN}.
meaning that the resistance R is:
R = R0 for V < V1, R1 for V1 <= V < V2, R2 for V2 <= V < V3, ... R(N-1) for V(N-1) <= V < VN, RN for VN <= V.
Note that the array has an odd number of elements since it starts with a resistance value (R0) and ends with a resistance value (RN). The piecewise-constant resistance means that the resistor has a piecewise-linear I-V relationship.
Note that this primitive is a pseudo-module to describe a structural netlist of electrical circuits and not a behavioral model by itself. The XMODEL simulator extracts an event-driven behavioral model at run-time based on the circuit network described by these circuit-level pseudo-modules.
Input/Output Terminals
Name | I/O | Type | Description |
pos | input | xreal | positive terminal |
neg | input | xreal | negative terminal |
Parameters
Name | Type | Default | Unit | Description |
R | real array | ‘{1.0} | ohms | PWC resistance |
Cpos | real | 0.0 | farads | pos-to-gnd capacitance |
Cneg | real | 0.0 | farads | neg-to-gnd capacitance |