# USB 3 Micro connector

> the latter class of legacy Micro connectors that preceded USB-C

**Wikidata**: [Q133458743](https://www.wikidata.org/wiki/Q133458743)  
**Source**: https://4ort.xyz/entity/usb-3-micro-connector

## Summary
The USB 3 Micro connector is a legacy USB connector class that preceded USB-C, supporting faster data transfer speeds (up to 10 Gbps) compared to earlier USB 2.0 Micro connectors. It belongs to both the Micro-USB and USB 3 connector families and was officially designated as the USB 3.1 Micro connector in documentation. This connector was eventually replaced by the reversible USB-C standard.

## Key Facts
- **Replaced by**: USB-C, which offers faster speeds and reversible design.
- **Subclass of**: Both Micro-USB and USB 3 connector classes.
- **Official names**: USB 3.1 Micro connector (documented in USB-IF specifications).
- **Aliases**: SuperSpeed+ Micro-USB, USB 10Gbps Micro connector, Micro-USB 3.0/3.1.
- **Speed**: Supported up to 10 Gbps (USB 3.1) or 5 Gbps (USB 3.0), depending on version.
- **Differentiated from**: USB 3 Standard connectors (larger form factor) and USB 2 Micro connectors (slower speeds).
- **Documentation**: Defined in USB 3.1 Legacy Connector and Cable Assembly Compliance Documents (e.g., 2011 and 2022 revisions).
- **Design**: Included distinct Micro-A, Micro-B, and Micro-AB receptacle configurations.

## FAQs
### Q: What replaced the USB 3 Micro connector?
A: The USB 3 Micro connector was replaced by USB-C, which provides higher performance and a reversible design.

### Q: How fast is USB 3 Micro compared to USB 2 Micro?
A: USB 3 Micro supports speeds up to 10 Gbps (USB 3.1) or 5 Gbps (USB 3.0), while USB 2 Micro is limited to 480 Mbps.

### Q: Is USB 3 Micro the same as Micro-USB 3.0?
A: Yes, "USB 3 Micro" and "Micro-USB 3.0" are aliases for the same connector, which added faster USB 3.0/3.1 capabilities to the Micro-USB form factor.

## Why It Matters
The USB 3 Micro connector played a critical role in bridging the gap between older USB 2.0 Micro devices and the need for faster data transfer rates. It enabled peripherals like external hard drives and smartphones to leverage USB 3.0/3.1 speeds (up to 10 Gbps) without requiring a complete redesign of the existing Micro-USB ecosystem. However, its introduction also highlighted the limitations of legacy connectors, such as bulkier designs and non-reversible plugs, which USB-C later addressed. This connector is significant as a transitional technology that supported high-speed data transfer in the pre-USB-C era, particularly in devices where space efficiency was a priority.

## Notable For
- **Dual-class heritage**: Combined the compact Micro-USB form factor with USB 3.0/3.1 performance standards.
- **10 Gbps capability**: Supported SuperSpeed+ (USB 3.1) speeds, a tenfold increase over USB 2.0 Micro.
- **Distinct plug/receptacle designs**: Included Micro-A, Micro-B, and hybrid Micro-AB receptacles for flexible connectivity.
- **Pre-USB-C legacy**: Represented the final evolution of Micro-USB before the industry shift to USB-C.

## Body
### Classification
The USB 3 Micro connector is classified as both a **Micro-USB** and **USB 3 connector**, reflecting its hybrid design. It was officially termed the **USB 3.1 Micro connector** in USB-IF documentation (e.g., 2022 revision of USB 3.2 standards).

### Technical Specifications
- **Speed**: Up to 10 Gbps (USB 3.1) or 5 Gbps (USB 3.0), depending on implementation.
- **Pin Configuration**: Added extra pins compared to USB 2.0 Micro to support faster data transfer.
- **Backward Compatibility**: Designed to work with USB 2.0 Micro connectors at slower speeds.

### History and Legacy
- **Introduction**: Emerged as part of the USB 3.0/3.1 standards to address speed limitations of USB 2.0 Micro.
- **Deprecation**: Replaced by USB-C, which unified connector designs and improved upon speed and usability.
- **Documentation**: Detailed in legacy USB-IF compliance documents, including the 2011 "USB 3.0 Cable and Connector Compliance Document."

### Physical Characteristics
- **Design**: Featured a double-headed "trapezoidal" shape distinct from Standard-A/B connectors.
- **Variants**: Included Micro-A (host), Micro-B (peripheral), and Micro-AB (dual-role) receptacles.
- **Size**: Smaller than Standard USB connectors but larger than USB-C.

## 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)