USB Power Delivery Specification finalised
July 19, 2012 // 11:41 a.m.
The USB Power Delivery Specification has finally been approved by the USB 3.0 Promoter Group and the USB 2.0 Promoter Group arms of the USB Implementers Forum, meaning manufacturers are now able to create standards-compliant systems providing up to 100W of power to client devices.
The USB 3.0 Promoter Group - a conglomeration of companies including Hewlett-Packard, Intel, Microsoft, Renesas, ST-Ericsson and Texas Instruments - is pushing the USB Power Delivery Specification as an upgrade to its 2008 USB 3.0 specification. While performance is unmodified over USB 3.0, power availability gets a significant boost with client devices able to demand up to 100W from host systems.
With so much power on demand, the Group sees a great deal of promise for bus-powered devices: as well as the current crop of bus-powered external hard drives and optical drives, which typically need two USB 2.0 connections to run, the new specification could potentially lead to single-cable USB-powered RAID boxes, large-format displays, surround-sound speaker systems, and even printers.
Better still, the standard allows for the direction of power flow to be flipped without having to remove the cable - allowing, for example, an external battery to charge from a laptop's USB port while connected to the mains, then the laptop to run from the same battery when mains power is disconnected.
The USB Power Delivery Specification also promises an end to the problem of vendor-specific power adapters, promising a future where - like the micro-USB port on mobile phones - any laptop can be charged using a simple USB connection. 'USB Power Delivery enables a path to greatly reduce electronic waste by eliminating proprietary, platform-specific chargers,' claimed Brad Saunders, chair of the USB 3.0 Promoter Group, of the specification's ratification. 'We envision a significant move toward universal charging based on this specification, most notably for charging notebook PCs using standardised USB power bricks or when connected to USB hubs and desktop displays that integrate USB Power Delivery capabilities.'
'We believe USB Power Delivery is the next big step in the USB evolution to provide high bandwidth data and intelligent power over a simple, single, ubiquitous cable,' added Robert Hollingsworth, general manager of the USB Products Group at SMSC. 'USB has always combined data and power over a single cable, and this is widely believed to be a major contributor to the present ubiquity of USB. USB Power Delivery builds on that success and adds full bi-directional power that can be renegotiated as system power needs change with the end-user.'
The specification is fully backwards-compatible with USB 2.0 and USB 3.0 - in other words, you won't fry anything if you connect it to the 'wrong' port - and the Groups are accepting adopters now. The USB Implementers Forum will then provide support for manufacturers looking to add the standard to their products.