## 3.3 Trans-capacitor

### 3.3.1 Syntax

`.TCAPacitor` label n+ n– nc+ nc– expression
`.TCAPacitor` label n+ n– nc+ nc– value {`IV=`initial-voltage}
`.TCAPacitor` label n+ n– model {`L=`length} {`W=`width} {`IC=`initial-voltage}

### 3.3.2 Purpose

Trans-capacitor, or charge transfer device.

### 3.3.3 Probes

All probes that apply to ordinary capacitors also apply here.

### 3.3.4 Comments

N+ and n– are the positive and negative element nodes, respectively. Nc+ and nc– are the positive and negative controlling nodes, respectively.
This device places a charge between the output nodes that depends on the voltage on its input nodes. If you parallel the input with the output, it becomes an ordinary capacitor. While the use of this device may appear straightforward, be careful. It is easy to use it in an unstable way.
All options, expressions, models, and probes that apply to ordinary capacitors can also be used here.
It is used internally in some transistor models.