# USB Mini-A plug

> a deprecated compact USB Type‑A plug, carrying only USB 1–2 and power, found at the host ends of cables, replaced by the USB 2 Micro‑A plug, itself later replaced by the USB 2 Type‑C plug

**Wikidata**: [Q102143294](https://www.wikidata.org/wiki/Q102143294)  
**Source**: https://4ort.xyz/entity/usb-mini-a-plug

## Summary
The USB Mini-A plug is a deprecated, compact USB Type-A connector designed for host ends of cables, supporting only USB 1.1/2.0 speeds and power delivery. It was superseded first by the USB 2 Micro-A plug and later by the USB 2 Type-C plug.

## Key Facts
-   **Status:** Deprecated and obsolete.
-   **Function:** Carries USB 1.1/2.0 data (up to 480 Mbps) and power (up to 5V/500mA).
-   **Location:** Found exclusively at the host ends of cables.
-   **Pins:** Utilizes a 5-pin configuration (VBUS, D−, D+, ID, GND).
-   **Replacement:** Replaced by the USB 2 Micro-A plug, which was itself replaced by the USB 2 Type-C plug.
-   **Compatibility:** Connects with USB Mini-AB receptacles (supporting On-The-Go) and USB Mini-A receptacles.
-   **Classification:** Instance of USB Mini-A connector, USB Mini plug, USB 2 Type-A plug, and USB Type-A plug.
-   **Design:** Features a distinct, compact form factor compared to the larger Standard-A plug.

## FAQs
### Q: What was the primary purpose of the USB Mini-A plug?
A: It was a compact plug used at the host end of cables to provide USB 1.1/2.0 data and power connections, primarily intended for smaller devices needing a smaller connector than the bulky Standard-A plug.

### Q: Why is the USB Mini-A plug deprecated?
A: It was deprecated because it was replaced by the more robust and widely supported USB 2 Micro-A plug, which was later superseded by the reversible and versatile USB 2 Type-C plug.

### Q: How many pins does a USB Mini-A plug have?
A: It features a 5-pin configuration: VBUS (power), D− (data minus), D+ (data plus), ID (On-The-Go), and GND (ground).

### Q: What is the difference between USB Mini-A and Mini-B plugs?
A: The USB Mini-A plug is the host end plug, while the USB Mini-B plug is the device end plug. Mini-A plugs connect to Mini-AB receptacles (for On-The-Go) or Mini-A receptacles, while Mini-B plugs connect to Mini-B receptacles.

## Why It Matters
The USB Mini-A plug represented an early attempt at standardizing compact connectors for mobile and portable devices. Its introduction addressed the need for a smaller host-side connector than the cumbersome Standard-A plug, paving the way for later, more successful compact designs like Micro-USB and eventually USB-C. Although deprecated, its design principles (especially the ID pin enabling USB On-The-Go functionality) were foundational for mobile device connectivity standards. Understanding its history and replacement sequence is crucial for maintaining legacy hardware and tracing the evolution of USB technology towards the universal Type-C standard.

## Notable For
*   Being the compact host-side plug in the original Mini connector family (alongside device-side Mini-B).
*   Featuring an ID pin enabling USB On-The-Go (OTG) functionality when used with a Mini-AB receptacle.
*   Being the first compact Type-A connector design standardized for USB host ends.
*   Its specific 5-pin pinout configuration delivering USB 1.1/2.0 data and power.

## Body
### Specifications
*   **Data Speeds:** USB 1.1 (12 Mbps) and USB 2.0 (High Speed, 480 Mbps).
*   **Power Delivery:** Up to 5V DC, limited to 500mA by USB 2.0 specification.
*   **Physical Form Factor:** Compact rectangular plug, smaller than the Standard-A plug.
*   **Pin Count:** 5 pins.
*   **Primary Use Case:** Host-side plug in cables for smaller mobile devices.

### Pinout
*   **Pin 1 (VBUS):** Red. Power supply (5V DC). Pin function: IC power-supply pin.
*   **Pin 2 (D−):** White. Data minus line (Differential pair).
*   **Pin 3 (D+):** Green. Data plus line (Differential pair).
*   **Pin 4 (ID):** USB On-The-Go (OTG) pin. Used to detect cable orientation and host/device role in OTG scenarios.
*   **Pin 5 (GND):** Black. Ground. Pin function: Ground.

### Replacements and Evolution
*   **Direct Replacement:** Superseded by the USB 2 Micro-A plug.
*   **Ultimate Replacement:** The USB 2 Micro-A plug and all other pre-C USB connectors were themselves superseded by the USB 2 Type-C plug.
*   **Obsolescence:** Declared deprecated and is no longer in active use or manufacture.

### Comparison & Distinction
*   **Opposite:** USB Mini-A receptacle (female port on cables or hosts).
*   **Different From:** USB Mini-A receptacle, USB Mini-B plug, USB 2 Standard-A plug, USB 2 Micro-A plug, USB Standard-A plug.
*   **Connects With:** USB Mini-AB receptacle (for On-The-Go), USB Mini-A receptacle (for standard host connection).
*   **Class Difference:** While categorized under USB Type-A plug (indicating host end), it is distinct from the larger Standard-A plug and belongs to the broader USB Mini connector class alongside Mini-B.

## References

1. [Source](https://www.usb.org/document-library/usb-31-legacy-cable-and-connector-revision-10)
2. [Source](https://www.usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-24)
3. [Source](https://www.usb.org/document-library/usb-32-revision-11-june-2022)
4. [Source](https://www.usb.org/document-library/usb-type-cr-connectors-and-cable-assemblies-compliance-document-rev-21b)
5. [Source](https://www.usb.org/document-library/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document)