3.8 Voltage Controlled Capacitor
3.8.1 Syntax
Device
Gxxxxxxx n+ n– VCCAP nc+ nc– expression
.VCCAP label n+ n– nc+ nc– expression
Model (optional)
.model mname C {args}
.model mname TABLE {args}
3.8.2 Purpose
Voltage controlled capacitor.
3.8.3 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
Farads per volt.
The simulator will faithfully give you a negative capacitor if it
seems appropriate. Usually, this part is used with a behavioral
modeling function, like PWL, which allows you to specify a table of
capacitance vs. voltage.
You may specify the value in any of these forms:
- A simple value. This is the capacitance in Farads with 1 volt applied
to the control port.
- An expression, as described in the behavioral modeling chapter.
- A model, as described in the behavioral modeling chapter. The
table model describes a table of capacitance vs. control voltage.
3.8.4 Probes
All probes that apply to ordinary capacitors also apply here.