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USB Power Delivery Specification finalised

Published on 19th July 2012 by Gareth Halfacree

The USB Power Delivery Specification allows USB ports to provide - or consume - up to 100W, meaning single-wire high-power devices are just around the corner.

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.

21 Comments

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Tyrmot 19th July 2012, 12:12

100W, pretty impressive

r3loaded 19th July 2012, 12:27

Quote:

Originally Posted by Tyrmot
100W, pretty impressive

Yep, it's 10x what Thunderbolt can do. Though USB power delivery cables are bound to be thicker since they'll be pushing 20A at assuming 5V.

Fruitloaf 19th July 2012, 13:41

I'm sure it'll take a number of years to filter through but I'm looking forward to it. Being able to cut down on the number of different sockets can only be a bonus even if you still need micro, mini and regular usb cables thats a huge step up from the huge number of different round, proprietary and different voltage connectors we have now.

greigaitken 19th July 2012, 13:54

100w - should only take a few hours to charge a future smartphone. I cant wait for this to be implemented into laptops.

.//TuNdRa 19th July 2012, 14:06

A few hours to charge a smartphone? A few minutes! Assuming it doesn't explode. Compared the current, what, 3 Amps on the USB? I am curious, though. Would make USB3 portable harddrives even better.

Bob1234 19th July 2012, 15:02

Quote:

Originally Posted by .//TuNdRa
Compared the current, what, 3 Amps on the USB? I am curious, though. Would make USB3 portable harddrives even better.

900mA for USB 3, 500mA for USB 2, both at 5V.

And yes, it would mean you could use possibly use 3.5" drives, although they need 12V as well as 5V, compared to the current 2.5" drives that need 1 cable for USB 3 or 2 if using USB 2.

Bakes 19th July 2012, 17:14

Quote:

Originally Posted by Bob1234
Quote:
Originally Posted by .//TuNdRa
Compared the current, what, 3 Amps on the USB? I am curious, though. Would make USB3 portable harddrives even better.

900mA for USB 3, 500mA for USB 2, both at 5V.

I was under the impression that iPhones would charge using 1amp from certain computers - and certainly from the wall?

schmidtbag 19th July 2012, 18:12

100w is stupid because most laptops won't be able to handle that, so if a device (such as a HDD) is designed to work with the 100w ports, it won't work on many mobile platforms.

ch424 19th July 2012, 18:31

Quote:

Originally Posted by schmidtbag
100w is stupid because most laptops won't be able to handle that, so if a device (such as a HDD) is designed to work with the 100w ports, it won't work on many mobile platforms.

Presumably the host and device negotiate how much power is available before allowing the device to draw anything. That's how the system works at the moment.

Also, the USB-IF says that they achieve 100W by "using higher voltages and currents", so don't worry about it drawing 20A at 5V!

Elton 19th July 2012, 20:05

So now we'll be charging phones faster. And Laptops!

Actually most chargers are ~100w these days. Not to mention that this specification does not mean it's constantly firing 100w worth of electricity (or 20A @ 5V) all the time at a product. I'm pretty sure they'd figure out a way to ensure that it would only output the maximum on certain devices.

Plus this at least allows for more powerful chargers. Tablet owners would like this I'm sure.

feedayeen 19th July 2012, 23:01

Since charging goes both ways, this is designed to power laptops too. They're really trying to use this as a logic compatible DC socket. Connect these sockets to a central computer and now you have a smart house! Larger devices can be outfitted with wifi/bluetooth support cheaply, but that wouldn't be efficient with light bulbs or similar devices.

CyberAngel 20th July 2012, 00:33

my laptop (hp-compaq) has a 90W charger, some has 65W
but currently they are all different (all my laptops and those of my friends)
USB 3.0+
[LIKE]

fluxtatic 20th July 2012, 07:20

Good to know there's a handshake first - my first thought was that I'm pretty sure I don't always have 100w available to draw from my PSU...not that I foresee actually powering anything that would draw 100w from my desktop.

Quote:

Originally Posted by Bakes
I was under the impression that iPhones would charge using 1amp from certain computers - and certainly from the wall?

Not sure about actual power figures, but yes. At least, it's been fairly common for Asus and a few other manufacturers to have a high-power USB port for fast charging of devices that support it, including iDevices.

Bob1234 20th July 2012, 10:04

Quote:

Originally Posted by Bakes
I was under the impression that iPhones would charge using 1amp from certain computers - and certainly from the wall?

They just charge slower from standard USB ports, although iPads dont charge at all, and power bricks are usually higher non-USB spec ampages.

The spec amps are just those provided as a maximum from a computer port, not the maximum you can safely conduct over a cable.

do_it_anyway 20th July 2012, 10:44

Charge the laptop battery over USB! This sounds cool.
In my family - of the 3, now broken, laptops 2 of them broke because the power input got wrecked with people yanking on the power lead and generally mistreating them.

If we could charge via USB3 then a broken USB port is a pain, but at least your PC isn't an expensive paperweight afterwards. You just switch to another of the USB's. :)

Bob1234 20th July 2012, 12:35

Quote:

Originally Posted by do_it_anyway
If we could charge via USB3 then a broken USB port is a pain, but at least your PC isn't an expensive paperweight afterwards. You just switch to another of the USB's. :)

Like that would happen, you just know that only one of the USB ports will be wired to the battery.

Kylevdm 20th July 2012, 12:55

I believe that at the moment USB ports supply .5A along the power lines unless the device/charger states that it can take/deliver more, this is done by shorting the data lines which in turn tells the device it can draw what it wishes, this is how the USB wall chargers work telling the device that it can draw as much power as it wants. Believe this is true for most devices bar apple who do something else to inform the device how much power it can pull.

Aracos 21st July 2012, 00:09

We're gonna need bigger 5V rails cap'n!

dark_avenger 23rd July 2012, 02:45

I'd imagine this is going to mean an added 12v wire or something as drawing 20a @5V is going to require a heavy bit of wire...

DriftCarl 23rd July 2012, 08:12

does this mean we will actually be able to have mug warmers that really do keep your mug warm in the winter?
Also I would like to invent a heater keyboard where nice warm air gets slowly released through the keys to keep the hands warm in winter too :D

Bob1234 24th July 2012, 15:03

Quote:

Originally Posted by DriftCarl
Also I would like to invent a heater keyboard where nice warm air gets slowly released through the keys to keep the hands warm in winter too :D

What you want there is a nice little Infra Red heat lamp, nicely warms your hands but nothing else.