[Arm-netbook] EOMA68 pinout change may be needed

Henrik Nordström henrik at henriknordstrom.net
Mon Feb 6 00:00:47 GMT 2012


sön 2012-02-05 klockan 23:10 +0000 skrev Phill Rogers:
> Hi, newbie alert (in this forum) so sorry if this has been covered.
> 
> Why not just use PoE ?
> http://en.wikipedia.org/wiki/Power_over_Ethernet

Because

a) Requires a PoE source.

b) Requires a fairly tolerant DC-DC power supply to make useable
voltages out of it in a safe manner. PoE is by no means a clean and nice
power source at convenient voltage.

c) Requires an Ethernet jack. We currently have Ethernet on the EOMA
connector only.

5V DC input is much simpler to work with, and more readily available in
the types of components we work with here. I.e. the power management
chip companion to A10 has everything builtin for dealing with a
reasonably stable 5V power source such as USB.

Please note that there is nothing that stops building a chassis for the
EOMA card that accepts PoE and powers the card from it via a suitable
DC-DC converter to 5V.

Regards
Henrik




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