The USB (Universal Serial Bus) standard has come a long way since its development in the 1990s, and the types of USB connectors have expanded as the standard has evolved. The USB standard defines cables, connectors and protocols used in a bus for communication between computers and peripherals and for power supply. USB has effectively replaced a variety of earlier interfaces, such as serial and parallel ports, as well as separate power chargers for portable devices.
The original USB specification only defined Standard-A and Standard-B plugs and receptacles. As the specification has been revised over the years, many more connector types have been included as you will see in our survey of connectors for the USB 2.0 Standard and how they have been modified in the most recent USB 3.0 SuperSpeed Standard.
Here are the connectors defined in the latest versions of the USB Standard:
The list of connector types defined by the USB Standard expanded for the first time with the introduction of USB 2.0 in 2000.
This type of plug and receptacle is designed for use on large USB peripherals such as a printer or a 1:15 DVD/CD Tower Publisher SLS – Part 260178.
As you can imagine the USB Standard-B plugs and receptacles are too big to be used on compact devices. This caused the miniaturization of the USB- B connector to what is now known as USB Mini-B. You will find this connector type being used with digital cameras, cellphones, and portable hard disk drives. It carries both power and data.
Micro-USB connectors also carry both power and data and they are even smaller and slimmer than the Mini-B. They’re designed to be used in small portable devices such as smartphones, GPS devices, and digital cameras. This category includes the Micro-A Plug and Receptacle, the Micro-B Plug and Receptacle and the versatile Micro-AB Receptacle. The Micro-AB Receptacle can accept either a Micro-A plug or a Micro-B plug. It is designed specifically to be used with USB On-The-Go devices. USB On-The-Go is a supplement to USB 2.0 that allows USB devices such as digital audio players or mobile phones to act as a host allowing a USB Flash Drive, mouse, or keyboard to be attached.
In our blog post about USB 3.0 we discussed how USB 3.0 cables include an additional 5 wires over the 4 wires that are typically found in USB 2.0 cables. Even with these extra wires, if you connect a Super Speed USB 3.0 device into a Hi-Speed USB 2.0 port, it will work, however at USB 2.0 rates. In order to achieve the data throughput of USB 3.0, you must have a USB 3.0 host, a USB 3.0 device, and a USB 3.0 cable.
A USB 3.0 Standard-A connector is commonly found on host controllers in computers and hubs. It’s designed to withstand continuous connection and disconnection. It will carry data from slower speed connections, and it is backwards compatible with USB 2.0 ports. Externally, this connector looks much like the USB 2.0-A.
A USB 3.0 Standard-B USB plug typically plugs into large devices such as the Aleratec 1:4 Blu-ray DVD CD Tower Publisher HLS Duplicator – Part 260165. USB 2.0-B plugs can be connected to USB 3.0-B receptacles, but USB 3.0-B plugs are not backwards compatible with USB 2.0-B receptacles.
The Micro-USB 3.0 plug and receptacle was designed for small, portable devices such as smartphones, GPS devices, and USB 3.0 Hubs. It looks much like the Micro-USB 2.0 but cables with this plug are not backwards compatible with USB 2.0 or USB 1.1 devices.