Re: [Arm-netbook] eoma68 router pcb

On 11/13/2013 08:41 PM, Christopher Thomas wrote:

On Wed, Nov 13, 2013 at 6:34 PM, luke.leighton
<luke.leighton@gmail.com <mailto:luke.leighton@gmail.com>> wrote:
     > anyone any experience at dealing with that much power on
    small boards
     > (4 amp @ 5V) ?

      LM1084?  any guidance on PCB layout anyone aware of?
Well, this will obviously be a 4 layer board, but I can say with the
MEBv2, we had tremendous problems with thermal dissipation of the
LM2576 at 9-12vdc, at 6vdc is was manageable, but the MEBv2++ are 2
layer boards, and with the addition of a secondary power plane, it
would probably have been fine. For the most recent versions, we are
using an AP6503a, and so far at 6, 9,12 vdc the heat is
non-existent. Not to mention, the local price of the AP6503 was .60c
cheaper than the LM2576, and is 85-95% more heat efficient.

My point in mentioning the LM2576, is that they are functionally similar to the LM1084, and both Linear.

CUI does board mount switching regulators that generate a lot less heat.

http://www.cui.com/product/power/dc-dc-converters/isolated/board-mount/20-w/...

PYB20-Q24-S5 is an isolated supply that will output 5V at 4A. But that digikey pricing suggests their not economical yet.

http://www.digikey.com/product-search/en/power-supplies-board-mount/dc-dc-co...