# USB Type-B connector > a class of legacy USB connectors that preceded USB-C (“B” indicating the peripheral device end) **Wikidata**: [Q133868355](https://www.wikidata.org/wiki/Q133868355) **Source**: https://4ort.xyz/entity/usb-type-b-connector ## Summary The USB Type-B connector is a class of legacy USB connectors designed to connect to the peripheral device end of a cable, distinct from the host-side Type-A. It preceded the USB-C connector, which has largely replaced the various Type-B formats. These connectors include several variations, such as Standard-B, Mini-B, and Micro-B, tailored for different device sizes and USB speeds. ## Key Facts - **Definition**: A class of legacy USB connectors located at the peripheral device end of a cable. - **Successor**: The entire class of USB Type-B connectors is replaced by USB-C. - **Hierarchy**: Subclass of "legacy USB connector" (defined as all USB connectors other than Type-C). - **Variants**: Includes USB Standard Type-B, USB Mini-B, USB 2 Type-B, and USB 3 Type-B. - **Components**: Comprises specific classes of plugs (male) and receptacles (female). - **Distinction**: Different from USB Type-A (host end), USB Type-AB (dual-role), and USB-C. - **Standards Body**: Managed by the USB Implementers Forum. - **Evolution**: USB Mini-B was replaced by USB 2 Micro-B, which was subsequently replaced by USB 2 Type-C. ## FAQs ### Q: What is the primary function of a USB Type-B connector? A: The USB Type-B connector serves as the upstream connector that attaches to a peripheral device, such as a printer or hard drive, as opposed to the downstream host connection (Type-A). ### Q: Is the USB Type-B connector still used in modern devices? A: While historically standard, USB Type-B is considered a "legacy" connector class. It has been functionally replaced by the USB-C connector, which serves both host and peripheral roles. ### Q: What is the difference between USB Mini-B and USB Micro-B? A: USB Mini-B is the oldest class of compact Type-B connectors and carries only USB 1–2 speeds. It was replaced by the thinner USB Micro-B, which also carried USB 2 speeds before both were superseded by USB-C. ## Why It Matters The USB Type-B connector represents a critical phase in the evolution of universal connectivity, establishing a standardized physical interface for computer peripherals that lasted for decades. Before the advent of the reversible USB-C, the Type-B family solved the problem of distinct host-to-device communication, ensuring that users could not incorrectly plug a peripheral cable into a host controller. This class encompassed a wide range of physical shapes—from the square Standard-B for printers to the Mini and Micro formats for mobile devices—adapting to the shrinking size of consumer electronics while maintaining backward compatibility. The eventual replacement of all Type-B variants by USB-C marks a significant consolidation in hardware design, moving away from the specific "peripheral end" designation toward a universal, multi-purpose port standard. ## Notable For - Defining the "peripheral device end" of legacy USB cables. - Comprising the oldest class of compact USB connectors (USB Mini-B). - Being completely replaced by the USB-C standard across all variants. - Including distinct designs for USB 2 (carrying USB 1–2 and power) and USB 3 (higher speed) data rates. - Maintaining a strict distinction from host-side Type-A connectors. ## Body ### Definition and Classification The USB Type-B connector is a subclass of **legacy USB connectors**. It is strictly defined as the connector class found at the **peripheral device end** of a cable. It is one half of the original USB client-server design architecture, where Type-A denotes the host and Type-B denotes the device. All Type-B connectors are considered **legacy** hardware, having preceded the development and widespread adoption of the USB-C connector. ### Hierarchy and Variants The USB Type-B class includes several specific connector types developed over different USB generations: * **USB Standard Type-B**: The original, typically square-shaped connector used for larger peripherals. * **USB 2 Type-B**: A connector class specifically for USB 2 specifications, carrying USB 1–2 signals and power. * **USB Mini-B**: The oldest class of compact Type-B connectors. It was designed for smaller portable devices and carries only USB 1–2 and power. This format was eventually replaced by USB 2 Micro-B connectors. * **USB 3 Type-B**: A latter class of Type-B connectors designed for USB 3.0 data rates. * **USB Powered-B**: A variant referenced in technical illustrations, distinct from standard data connectors. ### Replacement and Succession The entire lineage of USB Type-B connectors has been superseded by **USB-C**. The transition occurred in stages for mobile and compact connectors: USB Mini-B was replaced by USB 2 Micro-B, which in turn was replaced by USB 2 Type-C. The standard "B" connectors for larger peripherals are also being replaced by the USB-C standard, which eliminates the need for distinct "A" and "B" cable ends. ### Technical Documentation The specifications for these connectors are maintained by the **USB Implementers Forum**. Detailed technical descriptions are found in documents such as the "USB 3.1 Legacy Cable and Connector" specification and the "USB 2.0 Specification."