# USB Type-B receptacle

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

**Wikidata**: [Q133871517](https://www.wikidata.org/wiki/Q133871517)  
**Source**: https://4ort.xyz/entity/usb-type-b-receptacle

## Summary
A USB Type-B receptacle is a class of legacy USB ports located on peripheral devices, distinct from the host-side Type-A. It predates the USB-C standard, which has subsequently replaced this class of connectors. These receptacles appear in several variations, including Standard-B, Mini-B, and Micro-B formats.

## Key Facts
- **Definition:** A class of legacy USB receptacles where "B" indicates the peripheral device end of the connection.
- **Succession:** Preceded USB-C; the entire class has been replaced by the USB-C receptacle.
- **Parent Class:** Subclass of "USB Type-B connector" and "legacy USB receptacle."
- **Variations:** Includes USB Standard-B, USB Mini-B (the oldest compact version), USB Micro-B, USB 2 Type-B, and USB 3 Type-B.
- **Aliases:** Also known as USB-B receptacle, USB Type-B port, or USB-B port.
- **Differentiation:** Distinct from the USB Type-B plug (the cable end), the USB Type-A receptacle (host end), and the USB Type-AB receptacle.
- **Functionality:** Specific versions like the USB 2 Type-B receptacle carry only USB 1–2 signals and power, whereas USB 3 versions support newer standards.
- **Visuals:** Depicted in industry illustrations alongside variants like USB Powered-B and USB 3 Micro-B.

## FAQs
### Q: What is the main function of a USB Type-B receptacle?
A: It serves as the input port on a peripheral device (the "B" end), connecting to the host via a cable. It is distinct from the host-side receptacle (Type-A) and the plug attached to the cable.

### Q: Is the USB Type-B receptacle still used in modern devices?
A: It is considered a legacy class of receptacles. It has been replaced by the USB-C receptacle, which is now the standard for modern devices.

### Q: What are the different types of USB Type-B receptacles?
A: The class includes the Standard-B (for larger peripherals), Mini-B (the oldest compact version), and Micro-B (which replaced Mini-B). These variations also have specific USB 2 and USB 3 iterations.

## Why It Matters
The USB Type-B receptacle played a foundational role in the expansion of universal serial bus technology by defining the "peripheral device end" of connections. Before the introduction of the reversible USB-C, Type-B receptacles were essential for maintaining the host-to-device topology required by early USB standards (USB 1 through 3).

This class of connectors facilitated the "one-size-fits-all" vision of USB by offering different form factors—Standard, Mini, and Micro—tailored to the size and power needs of various peripherals, from printers to mobile phones. The evolution from the larger Standard-B to the compact Micro-B illustrates the industry's drive toward miniaturization. While these legacy ports are now being phased out in favor of the USB-C receptacle, understanding the Type-B family is crucial for maintaining legacy hardware and understanding the topology that governed computer connectivity for decades.

## Notable For
- **Defining the Peripheral End:** It is the specific component class that signifies the downstream device connection in legacy USB architectures.
- **Variety of Form Factors:** Notable for evolving from the large Standard-B to the Mini-B and finally the Micro-B to accommodate shrinking device sizes.
- **Legacy Status:** It is the primary class of connectors replaced by the universal USB-C standard.
- **Generational Distinction:** Distinct classes exist for USB 2 (carrying only USB 1–2 and power) and USB 3, marking significant speed and capability jumps.

## Body

### Definition and Classification
The USB Type-B receptacle is a class of connectors defined as "legacy USB receptacles" that preceded the USB-C standard. The "B" designation specifically indicates that the receptacle is located on the "peripheral device end" of the connection, as opposed to the "A" end found on the host (e.g., computer). Structurally, it is a subclass of the broader "USB Type-B connector" category.

### Variants and Evolution
The class encompasses several distinct subclasses designed for different device requirements over time:
- **USB Standard-B receptacle:** The original larger format, typically found on stationary peripherals.
- **USB Mini-B receptacle:** The oldest compact legacy receptacle. It carried only USB 1–2 and power and was eventually replaced by the Micro-B.
- **USB Micro-B receptacle:** A smaller class of legacy receptacles that succeeded the Mini-B.
- **USB 2 Type-B receptacle:** Specifically designed to carry USB 1–2 signals and power, replaced by the USB 2 Type-C receptacle.
- **USB 3 Type-B receptacle:** An updated class supporting USB 3 speeds.

### Replacement and Distinctions
The entire class of USB Type-B receptacles is differentiated from the plug (the male connector on the cable) and the USB Type-A receptacle (the host port). They are also distinct from the USB Type-AB receptacle, which could accept either A or B plugs in some contexts. Ultimately, the USB-C receptacle has replaced all variations of the USB Type-B receptacle in modern device architecture.