# LM339

> Quad comparator integrated circuit

**Wikidata**: [Q115902093](https://www.wikidata.org/wiki/Q115902093)  
**Source**: https://4ort.xyz/entity/lm339

## Summary
The LM339 is a quad comparator integrated circuit developed by National Semiconductor. It consists of four independent voltage comparators contained within a single electronic circuit formed on a small, flat piece of semiconductor material. The device is also recognized under the aliases LM139, LM239, and LM2901.

## Key Facts
*   **Developer:** National Semiconductor
*   **Classification:** Integrated circuit; Comparator
*   **Core Function:** Quad comparator (contains 4 independent comparators)
*   **Output Type:** Features 4 open collector outputs
*   **Aliases:** LM139, LM239, LM2901
*   **Material Structure:** Electronic circuit formed on a small, flat piece of semiconductor material
*   **Commons Category:** LM339 comparator

## FAQs
### Q: What is the primary function of the LM339?
A: The LM339 functions as a quad comparator integrated circuit, meaning it contains four independent voltage comparators on a single semiconductor chip.

### Q: Who developed the LM339?
A: The LM339 was developed by National Semiconductor.

### Q: What are the alternative names or aliases for the LM339?
A: This integrated circuit is also known by the aliases LM139, LM239, and LM2901.

## Why It Matters
The LM339 matters significantly in the field of electronics as a fundamental building block for circuit design. By integrating four independent comparators onto a single monolithic integrated circuit, it allows engineers to compare multiple voltage signals simultaneously within a compact footprint. This integration reduces the physical size and complexity of electronic assemblies compared to using discrete components.

As a product of National Semiconductor, the LM339 represents a standardized class of semiconductor components that facilitate signal processing and decision-making logic in hardware. Its specific architecture, featuring open collector outputs, makes it versatile for various logic families and voltage levels. The existence of multiple aliases (LM139, LM239, LM2901) indicates its widespread adoption and production across different manufacturers and performance grades, solidifying its role as a ubiquitous component in the industry.

## Notable For
*   **High Integration:** Distinguished by containing four comparators in a single package.
*   **Open Collector Design:** Notable for having four open collector outputs, a specific electrical configuration.
*   **Standardization:** Recognized as a standard integrated circuit class originally developed by National Semiconductor.
*   **Family of Devices:** Exists as part of a wider family of components identified by the LM139, LM239, and LM2901 aliases.

## Body

### Identity and Classification
The LM339 is classified as an integrated circuit, defined as an electronic circuit formed on a small, flat piece of semiconductor material. Specifically, it falls under the subclass of "comparator" devices. The Wikidata description explicitly defines it as a "Quad comparator integrated circuit."

### Internal Structure
The internal architecture of the LM339 is defined by its specific composition of parts. According to structured property data, the device consists of two primary component types:
*   **Comparators:** The device contains exactly 4 comparators.
*   **Open Collectors:** The device contains exactly 4 open collectors.

This structure allows the unit to function as a "quad" device, offering four independent channels for signal comparison within the single housing.

### Development and Naming
The entity was developed by **National Semiconductor**. It is associated with a specific image record in the Wikimedia Commons repository, depicting a physical board implementation (Taiwan Liton Electronic PA-3111-1B). The component is referenced globally under several aliases, including **LM139**, **LM239**, and **LM2901**, which generally refer to variations of the same core integrated circuit design.