# Op-Amp

Ideal operational amplifier

**Libraries:**

Simscape /
Foundation Library /
Electrical /
Electrical Elements

## Description

The Op-Amp block models an ideal operational amplifier (op-amp). The figure shows the implementation schematic.

The block implementation is based on the following assumptions:

The ideal op-amp gain

*A*is assumed to be infiniteThen, for finite output, must have

*V1*= 0Ideal op-amp also implies current from p to n is zero (

*i1*= 0)

These assumptions result in the following equations for the block:

equations v1 == p.v - n.v; v1 == 0; i1 == 0; end

For more information, click the **Source code** link in the
**Description** tab of the block dialog box.

The block has no parameters. However, you can initialize the **Current into output
node** variable prior to simulation. For more information, see Block-Level Variable Initialization.

### Variables

To set the priority and initial target values for the block variables prior to simulation, use
the **Initial Targets** section in the block dialog box or Property
Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Nominal values provide a way to specify the expected magnitude of a variable in a model.
Using system scaling based on nominal values increases the simulation robustness. Nominal
values can come from different sources, one of which is the **Nominal
Values** section in the block dialog box or Property Inspector. For more
information, see Modify Nominal Values for a Block Variable.

## Examples

## Ports

### Conserving

## Extended Capabilities

## Version History

**Introduced in R2007a**