OLIMEX OLinuXino-MAXI User Manual page 21

OLIMEX© 2012 OLinuXino User's Manual
The jumper 5V_E (5V Enable) which is closed by default enables powering the board via the power
supply circuit.
The 3.3V_E (3.3V Enable) jumper when closed enables the 3.3V power line.
Note the 3.3VIO_E jumper which by default is closed – if you open it (cut it) - it disables the U6
DC-DC converter and enables a built-in the iMX233 DC-DC. The problem is that the built-in DC-
DC has a limit of 250mA of amperage the chip heats a bit so we decided to put external DC-DC for
better stability. When working with 3.3VIO_E closed pay attention to the amperage used.
If 3.3VIO_E is closed(soldered) – it enables the additional DC-DC which is the better solution if
powering the board from external supply. However, if 3.3VIO_E is closed and you power the board
from a battery the LAN and the USB-HOSTs will not receive enough power and will be disabled.
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