PoweredUSB

PoweredUSB, also known as Retail USB, USB PlusPower, and USB +Power, is an addition to the Universal Serial Bus standard that allows for higher-power devices to obtain power through their USB host instead of requiring an independent power supply or external AC adapter. It is mostly used in point-of-sale equipment, such as receipt printers and barcode readers.

History

PoweredUSB, as a proprietary variant of USB, was developed and proposed by IBM, Berg (now FCI), NCR and Microsoft between 1998 and 1999, with the last revision (0.8g) issued in 2004. The specification is not endorsed by the USB Implementers Forum (USB-IF). IBM, who owns patents to PoweredUSB, charges a licensing fee for its use.

PoweredUSB was licensed by Hewlett-Packard, Cyberdata, Fujitsu, Wincor and others.

Implementation

PoweredUSB uses a more complex connector than standard USB, maintaining the standard USB 1.x/2.0 interface for data communications and adding a second connector for power. Physically, it is essentially two connectors stacked such that the bottom connector accepts a standard USB plug and the top connector takes a power plug.