USB PD continues the use of the bilateral 5% tolerance, with allowable voltages of PDO ±5% ±0.5V (eg. for a PDO of 9.0V, the maximum and minimum limits are 9.95V and 8.05V, respectively). [42] USB 3.2 Specification Language Usage Guidelines from USB-IF" (PDF). Archived (PDF) from the original on 3 November 2021 . Retrieved 4 September 2019. Universal Serial Bus Specification (PDF) (Technical report). 1996. p.29. v1.0. Archived (PDF) from the original on 30 January 2018. Upstream USB connectors supply power at a nominal 5 V DC via the V_BUS pin to downstream USB devices.

Technical Note. Galvanic Isolation" (PDF). iSYSTEM. 2021. Archived (PDF) from the original on 21 December 2021 . Retrieved 13 February 2022. Installing a device that relies on the USB standard requires minimal operator action. When a user plugs a device into a port on a running computer, it either entirely automatically configures using existing device drivers, or the system prompts the user to locate a driver, which it then installs and configures automatically. One port to rule them all: Thunderbolt3 and USB Type-C join forces". Archived from the original on 2 June 2015 . Retrieved 2 June 2015.Battery Charging v1.2 Spec and Adopters Agreement" (ZIP). USB Implementers Forum. 7 March 2012. Archived from the original on 6 October 2014 . Retrieved 13 May 2021. During CES 2020, USB-IF and Intel stated their intention to allow USB4 products that support all the optional functionality as Thunderbolt 4 products. The first products compatible with USB4 are expected to be Intel's Tiger Lake series and AMD's Zen 3 series of CPU, released in 2020.

Micro-USB was embraced as the "Universal Charging Solution" by the International Telecommunication Union (ITU) in October 2009. [18] The Micro plug design is rated for at least 10,000 connect-disconnect cycles, which is more than the Mini plug design. [13] [16] The Micro connector is also designed to reduce the mechanical wear on the device; instead, the easier-to-replace cable is designed to bear the mechanical wear of connection and disconnection. The Universal Serial Bus Micro-USB Cables and Connectors Specification details the mechanical characteristics of Micro-A plugs, Micro-AB receptacles (which accept both Micro-A and Micro-B plugs), Double-Sided Micro USB, and Micro-B plugs and receptacles, [16] along with a Standard-A receptacle to a Micro-A plug adapter. The limit to device power draw is stated in terms of a unit load which is 100mA for USB 2.0, or 150mA for SuperSpeed (i.e. USB 3. x) devices. Low-power devices may draw at most 1 unit load, and all devices must act as low-power devices before they are configured. A high-powered device must be configured, after which it may draw up to 5 unit loads (500mA), or 6 unit loads (900mA) for SuperSpeed devices, as specified in its configuration because the maximum power may not always be available from the upstream port. [43] [44] [45] [46] USB 2.0 uses two wires for power (V BUS and GND), and two for differential serial data signals. Mini and micro connectors have their GND connections moved from pin #4 to pin #5, while their pin #4 serves as an ID pin for the On-The-Go host/client identification. [6] a b "Universal Serial Bus Device Class Specification for Device Firmware Upgrade, Version 1.1". USB Implementers Forum. 15 October 2004. pp.8–9. Archived (PDF) from the original on 11 October 2014 . Retrieved 8 September 2014.For a product developer, using USB requires the implementation of a complex protocol and implies an "intelligent" controller in the peripheral device. Developers of USB devices intended for public sale generally must obtain a USB ID, which requires that they pay a fee to the USB Implementers Forum (USB-IF). Developers of products that use the USB specification must sign an agreement with the USB-IF. Use of the USB logos on the product requires annual fees and membership in the organization. [12] History [ edit ] The basic USB trident logo [15] USB logo on the head of a standard Type-A (Standard-A) plug Connectors [ edit ] Comparison of legacy USB connector plugs, omitting the current standard Type-C plugs

Full Speed USB Maximum Theoretical Throughput". Microchip Technology Incorporated. 23 March 2021. Archived from the original on 26 March 2021 . Retrieved 23 March 2021. Thunderbolt combines PCI Express and Mini DisplayPort into a new serial data interface. Original Thunderbolt implementations have two channels, each with a transfer speed of 10Gbit/s, resulting in an aggregate unidirectional bandwidth of 20Gbit/s. [115] a connection-oriented, tunneling architecture designed to combine multiple protocols onto a single physical interface, so that the total speed and performance of the USB4 Fabric can be dynamically shared. [2] Starting with the USB 3.2 specification, USB-IF introduced a new naming scheme. [37] To help companies with branding of the different operation modes, USB-IF recommended branding the 5, 10, and 20Gbit/s operation modes as SuperSpeed USB 5Gbps, SuperSpeed USB 10Gbps, and SuperSpeed USB 20Gbps, respectively. [38].There are so-called cables with A plugs on both ends, which may be valid if the "cable" includes, for example, a USB host-to-host transfer device with two ports. [3] This is, by definition, a device with two logical B ports, each with a captive cable, not a cable with two A ends.