## 3.10 Voltage Controlled Resistor

### 3.10.1 Syntax

Preferred syntax:
`.VCR` label n+ n– nc+ nc– expression
Alternate syntax:
`G` xxxxxxx n+ n– VCR nc+ nc– expression

### 3.10.2 Purpose

Voltage controlled resistor.

### 3.10.3 Comments

N+ and n– are the positive and negative element (output) nodes, respectively. Nc+ and nc– are the positive and negative controlling nodes, respectively. Value is the transfactor in ohms per volt.
The simulator will faithfully give you a negative resistor if it seems appropriate. Usually, this part is used with a behavioral modeling function, like PWL, which allows you to specify a table of resistance vs. voltage.