Is it possible to negotiate a USB 3 power level, such as 900 mA, if the device is connected to a USB 3 port, without being a device capable of the higher speeds? I'd like to use this higher level if available for charging.


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The answer to a related question suggests this will not be possible.

When operating at USB 2 (or below) the unit of power is 2mA. At USB 3.0 the unit is 8mA, allowing a higher maximum power.

Therefore unless you can negotiate as a USB 3.0 device you will be limited to the same ~500mA maximum (an unsigned 8 bit integer multiplied by 2mA).


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