# USB Powered-B receptacle

> a legacy USB receptacle that preceded USB-C (“B” indicating the peripheral device end)

**Wikidata**: [Q133868545](https://www.wikidata.org/wiki/Q133868545)  
**Source**: https://4ort.xyz/entity/usb-powered-b-receptacle

## Summary
The USB Powered-B receptacle is a legacy USB connector that preceded USB-C, designed for peripheral devices ("B" indicating the device end). It was part of the USB 3.0 standard and included power delivery capabilities, though it lacked the bidirectional data and power features of USB-C.

## Key Facts
- A legacy USB receptacle introduced before USB-C, serving as the peripheral device end ("B").
- Part of the USB 3.0 standard, supporting power delivery alongside data transmission.
- Includes pins for VBUS (red), D− (white), D+ (green), and GND (black), with additional USB 3.0 pins (SSTX−, SSTX+, SSRX−, SSRX+).
- Officially named "USB Powered-B receptacle" as per USB Implementers Forum standards.
- Replaced by USB-C receptacles, which offer bidirectional power and data transfer.
- Connects with USB Powered-B plugs, USB 3 Standard-B plugs, and USB 2 Standard-B plugs.
- Includes a ground drain (GND_DRAIN) and DPWR pin for power management.

## FAQs
### Q: What is the difference between USB Powered-B and USB-C receptacles?
A: USB Powered-B receptacles were part of the USB 3.0 standard and supported power delivery but lacked bidirectional data and power features. USB-C receptacles replaced them, offering reversible connections and enhanced power delivery.

### Q: What pins does a USB Powered-B receptacle have?
A: It includes VBUS (red), D− (white), D+ (green), and GND (black) pins, along with additional USB 3.0 pins like SSTX−, SSTX+, SSRX−, SSRX+, and GND_DRAIN.

### Q: Is the USB Powered-B receptacle still used today?
A: No, it has been largely replaced by USB-C receptacles, which are more versatile and widely adopted.

## Why It Matters
The USB Powered-B receptacle was a significant step in USB evolution, introducing power delivery alongside data transmission in the USB 3.0 standard. However, its lack of bidirectional capabilities and reversible design limitations led to its eventual replacement by USB-C. This transition was crucial for modern computing and mobile devices, as USB-C offered more efficient power delivery and a universal connector design. The USB Powered-B receptacle remains historically important as a precursor to the more advanced USB-C standard.

## Notable For
- One of the first USB connectors to integrate power delivery with data transmission.
- Part of the USB 3.0 standard, supporting higher data transfer rates.
- Designed for peripheral devices, indicated by the "B" designation.
- Includes a ground drain (GND_DRAIN) for improved electrical performance.
- Officially recognized by the USB Implementers Forum as a legacy standard.

## Body
### Design and Function
The USB Powered-B receptacle was designed as part of the USB 3.0 standard, introducing power delivery alongside data transmission. It featured a standard pinout with VBUS (red), D− (white), D+ (green), and GND (black) pins, along with additional USB 3.0-specific pins like SSTX−, SSTX+, SSRX−, SSRX+, and GND_DRAIN. The "B" designation indicated its use for peripheral devices, contrasting with the "A" designation for host devices.

### Legacy and Replacement
The USB Powered-B receptacle was succeeded by USB-C, which offered bidirectional power and data transfer, as well as a reversible design. This transition was driven by the need for a more versatile and universally compatible connector. The USB Powered-B receptacle remains a historical reference point in USB evolution, highlighting the advancements made in connector technology.

### Standards and Compliance
The USB Powered-B receptacle was officially recognized by the USB Implementers Forum, with its specifications detailed in documents such as the USB 3.1 Legacy Cable and Connector Revision 1.0. It was part of the broader USB 3.0 and USB 3.1 standards, ensuring compatibility with existing devices and systems.

### Pinout and Electrical Specifications
The pinout of the USB Powered-B receptacle included:
- **VBUS (Pin 1)**: Red, providing power (5V at 500mA).
- **D− (Pin 2)**: White, differential data line.
- **D+ (Pin 3)**: Green, differential data line.
- **GND (Pin 4)**: Black, ground.
- **SSTX− (Pin 5)**: SuperSpeed transmit differential line.
- **SSTX+ (Pin 6)**: SuperSpeed transmit differential line.
- **GND_DRAIN (Pin 7)**: Ground drain for improved electrical performance.
- **SSRX− (Pin 8)**: SuperSpeed receive differential line.
- **SSRX+ (Pin 9)**: SuperSpeed receive differential line.
- **DPWR (Pin 10)**: Power pin for additional power delivery.

These specifications ensured reliable data and power transmission, making it a key component in USB 3.0 devices.

## 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)
6. [Source](https://www.usb.org/document-library/usb-20-specification)