Brand New USB Specification Allows Up to 100W of Power

Brand New USB Specification Allows Up to 100W of Power

Many forums, comment threads, and even bloggers have brought up in the past how they’d like their USB connectors to transfer a bit more electrical power to their various USB devices. Smartphones, laptops, tablets, and other gadgets take a lifetime to fully charge, sometimes only work on “powered” USB ports, or have to be plugged into a wall socket to get any real charge going.

Luckily, the USB implementers forum, the group also responsible for the SuperSpeed USB specification, have released the next generation of the USB 3.0 standard will include support for a whopping 100 watts of power. That’s enough electrical power to keep ten usb drives running, or an LCD, or even an entire laptop. And you can use the same cables and ports you already have.

This is a huge increase from the previous 5 watt standard or 10 extended watts found in normal USB ports. Even the high-power sounding Apple Thunderbolt port can only deliver up to 10W. With 5 GB/s and 100W of power, this USB specification is taking it to a whole new level. The ability to power larger and more sophisticated device, like printers, monitors, and speakers, could make it even more universal than it already is.

It’s definitely a big step up from either the Thunderbolt or Light Peak designs, which, while they can handle the data from ten external drives, likely couldn’t power more than two of them. The USB cables should be able to take on about 1.5 amps of current. It’s not entirely clear how the power load division will be altered, but it would seem reasonable to say that they will be increasing the number of concurrent loads.

Even though the new USB 3.0 specification would use existing usb cables, there are still some potential issues to consider. Not all motherboards and power supplies are prepared for this type of power transfer, and improperly taken care of, these high wattages could burn out components, tax the PSU, and cause severe overheating. Low-quality charge USB cables already melt and catch on fire regularly. But it’s likely not that big a problem since power should be carefully monitored by the USB controller and it should only use wattages and currents tested and known to be safe with given classes of USB devices.

My only concern is whether only a few usb devices and computers will have the power overhead to support this spec, since they likely pick PSUs carefully made to the power draw requirements of the system. Concerns of outdated hardware bursting into flames aside, I think this is a very exciting development. It’s a serious increase and could enable a completely different accessory ecosystem. Don’t expect to be able to charge your usb devices ten times faster just yet however, but after the design is finalized in September 2012 you could expect some very interesting USB-powered devices.

Vincent Clarke

Vincent Clarke is the Universal Serial Bus (USB) Guru for When he's not writing tutorials and catching up on the latest USB news, Vincent is busy preparing his next blog post and answering USB questions from his readers and subscribers.

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