universal Serial Bus

Universal Serial Bus (USB)

The certified USB logo
Type	Bus
Production history
Designer	Compaq DEC IBM Intel Microsoft NEC Nortel
Designed	January 1996; 24 years ago (1996-01)
Produced	Since May 1996
Superseded	Serial port, parallel port, game port, Apple Desktop Bus, PS/2 port, and FireWire (IEEE 1394)
General specifications
Length	2–5 m (6 ft 7 in–16 ft 5 in) (by category)
Width	12 mm (type-A) 8.45 mm (type-B) 6.8 mm (mini/micro) 8.25 mm (type-C)
Height	4.5 mm (type-A) 7.26 mm (type-B) 10.44 mm (type-B SuperSpeed) 1.8–3 mm (mini/micro) 2.4 mm (type-C)
Hot pluggable	Yes
External	Yes
Cable	4 wires plus shield 9 wires plus shield (SuperSpeed)
Pins	4: 1 power, 2 data, 1 ground 5 (On-The-Go) 9 (SuperSpeed) 11 (Powered-B SuperSpeed) 24 (USB-C)
Connector	Unique
Electrical
Signal	5 V DC
Max. voltage	5.00+0.25 −0.60 V 5.00+0.25 −0.55 V (USB 3.0) 20.00 V (PD)
Max. current	0.5 A (USB 2.0) 0.9 A (USB 3.0) 1.5 A (BC 1.2) 3 A (USB-C) Up to 5 A (PD)
Data
Data signal	Packet data, defined by specifications
Width	1 bit
Bitrate	1.5; 12; 480; 5,000; 10,000; 20,000 Mbit/s (depending on mode)
Max. devices	127
Protocol	Serial
Pin out
The USB-A plug (left) and USB-B plug (right)
Pin 1		VBUS (+5 V)
Pin 2		Data−
Pin 3		Data+
Pin 4		Ground

USB-A 3.1 Gen 1 (3.0, Also later renamed USB 3.2 Gen 1) ports

Universal Serial Bus (USB) is an industry standard that establishes specifications for cables and connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad variety of USB hardware exists, including several different connectors, of which USB-C is the most recent.

Released in 1996, the USB standard is currently maintained by the USB Implementers Forum (USB-IF). There have been four generations of USB specifications: USB 1.x, USB 2.0, USB 3.x and USB4.