OLIMEX© 2018
A20-OLinuXino-MICRO user's manual
6.6 USB_HOST connector
The part of the schematic related to the USB_HOST connector is listed below:
The USB_HOST connector features two levels – called USB1 and USB2 in the schematic. The
connector is situated between the USB_OTG and the HDMI connector. Each of slots them features
a low loss power distribution switch SY6280 which protects the board in case the devices you have
plugged to each level USB_HOST try to draw more than the allowed current.
Please note the pads of capacitors C222 and C223 where you can solder tantalum capacitors
(220uF/18V). If you do so you would be able to increase the stability of the powering by the USB
ports when the powered device has high current consumption.
The maximum current available on each slot of the 5V USB_HOST is different! USB1 is capable of
providing 1000mA of current; while USB2 is capable of providing only 523mA. If you have a
device that draws higher current please plug it into USB1.
The SY6280 responsible for the USB1 is enabled by USB0-DRV1 (processor pin A4).
The SY6280 responsible for the USB2 is enabled by USB0-DRV2 (processor pin A5).
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