---
title: Constant (v1.4)
description: API reference for qiskit.pulse.library.Constant in qiskit v1.4
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/1.4/qiskit.pulse.library.Constant
---

# Constant

*class* `qiskit.pulse.library.Constant(duration, amp, angle=0.0, name=None, limit_amplitude=None)`

Bases: [`object`](https://docs.python.org/3/library/functions.html#object)

A simple constant pulse, with an amplitude value and a duration:

$$
f(x) = \text{amp}\times\exp\left(i\text{angle}\right)    ,  0 <= x < duration
f(x) = 0      ,  elsewhere
$$

> **Deprecated since version 1.3**
>
> The class `qiskit.pulse.library.symbolic_pulses.Constant` is deprecated as of Qiskit 1.3. It will be removed in Qiskit 2.0. The entire Qiskit Pulse package has been deprecated.

## Attributes

### alias

Default value: `'Constant'`