DIY via computer

Jul 07, 2009 23 Replies

Which bit of the standard do you think they've broken?

The rules for operating devices in USB2.0 are exactly the same as they always were. They have added a standard for supporting battery charging.

USB3.0 (a new standard) introduces higher current limits for operating, as well as charging.

MBQ

The fact that the 100mA current limit for unnegociated connections has effectively disappearered. I may have the wrong end of the stick but I'd have to read actual spec rather than a bit of hearsay on Wikipedia or other raddom web pages.

But I'm under the impression that the host port actually limited the current to 100mA unless the client asked for (and was granted) the higher amount of 500mA. Not just that the client shouldn't try to draw more than 100/500mA.

This battery charging addition removes such a current limit for un-negociated connections.

I am somewhat amused that such deep analysis has been applied to what appeared to me to be a spoof advert.

Chris

I've never found a host port which actually polices the current draw.

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