# USB Type-AB receptacle

> a class of legacy USB receptacles that preceded USB-C, “AB” indicating they accept both Type-A and Type-B plugs

**Wikidata**: [Q133869685](https://www.wikidata.org/wiki/Q133869685)  
**Source**: https://4ort.xyz/entity/usb-type-ab-receptacle

## Summary
USB Type-AB receptacle is a legacy USB connector class that accepts both Type-A and Type-B plugs, serving as a bridge between early USB standard variants before being superseded by USB-C. Its "AB" designation signifies dual compatibility with these distinct plug types.

## Key Facts
- Accepts both Type-A and Type-B plugs, distinguishing it as a hybrid legacy receptacle
- Part of the "legacy USB receptacle" and "legacy USB connector" classes, excluding all USB-C variants
- Replaced entirely by the USB-C receptacle across modern standards
- Includes variants like USB Micro-AB and USB 2 Type-AB receptacles with specific USB version compatibility
- Aliases include "USB On-The-Go receptacle" and "USB-AB port" due to its role in OTG functionality
- Officially documented in USB specifications (e.g., USB 2.0, USB 3.0 compliance documents)
- Classified under Wikimedia Commons category "USB Type-AB receptacles"

## FAQs
### Q: What does "Type-AB" mean in USB connectors?  
A: "AB" indicates the receptacle accepts both Type-A and Type-B plugs, enabling compatibility with different USB device interfaces before USB-C standardized connectivity.

### Q: When were USB Type-AB receptacles phased out?  
A: They were replaced by USB-C receptacles, with phasing occurring as USB-C became the universal standard starting with USB 3.2 and later specifications.

### Q: How does Type-AB differ from USB-C?  
A: Type-AB only supports USB 1–2 standards and older variants, while USB-C offers higher data rates, power delivery, and reversible plug orientation—making Type-AB obsolete for modern applications.

## Why It Matters
USB Type-AB receptacles represented a critical transitional phase in USB evolution, addressing the need for interoperability between Type-A (host) and Type-B (peripheral) devices in an era before standardized reversible connectors. Their dual-compatibility design simplified device interfaces during USB 2.0's peak, but became limiting as data speeds increased. By acknowledging Type-AB's legacy, we understand why USB-C's unification of power, data, and device roles—along with its compact, reversible form—resolved critical usability issues that fragmented the USB ecosystem for over a decade.

## Notable For
- **Hybrid Compatibility**: Unique dual acceptance of Type-A and Type-B plugs bridged early USB device standards  
- **OTG Enabler**: Primary physical interface for USB On-The-Go functionality in smartphones and PDAs  
- **Legacy Standard**: Defined the "AB" designation for receptacles accepting both plug orientations  
- **Predecessor Role**: Direct technical predecessor to USB-C's unified-receptacle concept  

## Body
### Overview
The USB Type-AB receptacle is a class of legacy USB connectors characterized by their ability to accommodate both Type-A and Type-B plugs. Their naming convention explicitly denotes this dual-compatibility feature, distinguishing them from single-format receptacles like Type-A or Type-B alone. As part of the broader "legacy USB receptacle" classification, Type-AB variants represent an interim solution before USB-C's emergence.

### Technical Variants
- **USB Micro-AB Receptacle**: Legacy USB 3 variant accepting Micro-A and Micro-B plugs, replaced by Full-Featured Type-C  
- **USB 2 Type-AB Receptacle**: USB 2.0-specific version supporting only USB 1–2 standards (no USB 3+), replaced by USB 2 Type-C  
- **USB Mini-AB Receptacle**: Deprecated miniaturized variant with similar dual-plug acceptance  

### Standardization Context
Officially defined in USB-IF specifications including:  
- USB 2.0 Specification  
- USB 3.0 Compliance Documents  
- USB 3.1 Legacy Cable and Connector Revision 1.0  

### Classification
- **Subclass of**: Legacy USB receptacle, Legacy USB connector  
- **Exclusions**: USB-C, USB-C receptacle, Type-A/B connectors  
- **Replacement**: Entirely superseded by USB-C receptacles across all versions  
- **Commons Category**: "USB Type-AB receptacles" on Wikimedia Commons  

### Documentation Sources
Authoritative specifications maintained by USB Implementers Forum (USB-IF):  
- [USB 2.0 Specification](https://www.usb.org/document-library/usb-20-specification)  
- [USB 3.0 Compliance Document](https://www.usb.org/sites/default/files/CabConn_3_0_Compliance_Document_v1.02_2011-10-04.pdf)  
- [USB 3.1 Legacy Cable and Connector](https://www.usb.org/document-library/usb-31-legacy-cable-and-connector-revision-10)