## 3.12 `I`: Independent Current Source

### 3.12.1 Syntax

`I` xxxxxxx n+ n-- value
`I` xxxxxxx n+ n-- expression
`.ISOurce` label n+ n-- expression

### 3.12.2 Purpose

Independent current source.

### 3.12.3 Comments

N+ and n-- are the positive and negative element nodes, respectively. Positive current flow is from the positive node, through the source, to the negative node. Value is the current in Amperes.
All of the SPICE time dependent functions (`pulse`, `sin`, `exp`, `pwl`, and `sffm` are supported. An additional function `generator` emulates a laboratory type function generator, for a more convenient signal input to the circuit.