# USB 3 Micro-AB receptacle

> the legacy USB 3 receptacle which accepts all Micro‑A and Micro‑B plugs, replaced by the Full-Featured Type‑C receptacle

**Wikidata**: [Q133458746](https://www.wikidata.org/wiki/Q133458746)  
**Source**: https://4ort.xyz/entity/usb-3-micro-ab-receptacle

## Summary
The USB 3 Micro-AB receptacle is a legacy USB 3 connector designed to accept both Micro-A and Micro-B plugs. It served as a versatile interface in the USB 3.0 and 3.1 eras but has been officially replaced by the Full-Featured Type-C receptacle. This receptacle is distinct for its 10-pin configuration and its role as a predecessor to modern USB-C connections.

## Key Facts
- **Official Name:** USB 3.1 Micro-AB receptacle.
- **Replaced By:** Full-Featured Type-C receptacle.
- **Compatibility:** Accepts USB 3 Micro-A, USB 3 Micro-B, USB 2 Micro-A, and USB 2 Micro-B plugs.
- **Pin Configuration:** Features 10 leads (pins) to support Superspeed data transfer.
- **Class:** It is an instance of USB Type-AB receptacle, USB 3 connector, and USB 3 Micro receptacle.
- **Standard:** Defined by USB 3.1 legacy cable and connector specifications.
- **Aliases:** USB 10Gbps Micro-AB receptacle, USB 5Gbps Micro-AB receptacle, USB SS Micro-AB receptacle, USB 3.0 Micro-AB connector.

## FAQs
### Q: What plugs are compatible with the USB 3 Micro-AB receptacle?
A: This receptacle is designed to accept all Micro-A and Micro-B plugs, covering both USB 2.0 and USB 3.0/3.1 standards.

### Q: Has the USB 3 Micro-AB receptacle been replaced?
A: Yes, it is a legacy connector that has been replaced by the Full-Featured Type-C receptacle.

### Q: How many pins does the USB 3 Micro-AB receptacle have?
A: The receptacle has 10 leads (pins), which include power, ground, data, and Superspeed transmit/receive pairs.

## Why It Matters
The USB 3 Micro-AB receptacle represents a significant transitional phase in connectivity technology. Before the widespread adoption of the reversible USB-C, the Micro-AB receptacle provided a crucial "universal" solution for mobile and peripheral devices by allowing a single port to accept both "A" (host) and "B" (device) Micro plugs. This capability was essential for USB On-The-Go (OTG) functionality, allowing devices like smartphones to act as hosts for peripherals like flash drives. Although it is now considered a legacy interface replaced by the more versatile USB-C, the USB 3 Micro-AB receptacle bridged the gap between simple charging/sync ports and high-speed, dual-role data interfaces. Its existence highlights the iterative engineering steps taken to reach the current standardized, high-speed, and reversible connectivity standard used today.

## Notable For
- Being a legacy USB 3 receptacle capable of accepting both Micro-A and Micro-B plug types.
- Featuring a 10-pin design that integrates USB 2.0 pins with Superspeed differential pairs.
- Officially serving as the predecessor to the Full-Featured Type-C receptacle.
- Supporting USB On-The-Go functionality via a dedicated ID pin.

## Body
### Technical Specifications
The USB 3 Micro-AB receptacle is a component of the legacy USB 3 connector class. It is distinguished by its 10-lead structure, which supports USB 3.1 (formerly 3.0) data transfer rates. The pinout is organized as follows:

*   **Power & Ground:**
    *   **Pin 1 (VBUS):** Red, IC power-supply pin (5V).
    *   **Pin 5 (GND):** Black, ground.
    *   **Pin 8 (GND_DRAIN):** Ground drain for signal integrity.
*   **USB 2.0 Data:**
    *   **Pin 2 (D−):** White.
    *   **Pin 3 (D+):** Green.
*   **On-The-Go (OTG):**
    *   **Pin 4 (ID):** Used to identify the cable plug type (A or B) for OTG roles.
*   **Superspeed Data (TX/RX):**
    *   **Pin 6 (SSTX−) & Pin 7 (SSTX+):** Transmitter differential pair.
    *   **Pin 9 (SSRX−) & Pin 10 (SSRX+):** Receiver differential pair.

### Design and Usage
Physically, the USB 3 Micro-AB is categorized as a USB 3 Micro connector and a USB Micro-AB receptacle. Its defining feature is the ability to accept a wide range of plug types, specifically:
*   USB 3 Micro-A plug
*   USB 3 Micro-B plug
*   USB 2 Micro-A plug
*   USB 2 Micro-B plug

This flexibility made it a versatile choice for devices requiring OTG capabilities before the industry transitioned to the USB-C ecosystem. It is distinct from the standard USB 3 Micro-B receptacle and the older USB 2 Micro-AB receptacle. Visual diagrams and schematics of the receptacle indicate the requirement of a grey insulator color for the USB 3 variant.

## 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/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document)
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/usb-type-cr-cable-and-connector-specification-release-24)
6. [Source](https://www.usb.org/document-library/usb-20-specification)