On Tue, Nov 5, 2013 at 3:46 PM, joem joem@martindale-electric.co.uk wrote:
On Tue, 2013-11-05 at 13:48 +0000, luke.leighton wrote:
perfect. thanks.
On Tue, Nov 5, 2013 at 1:18 PM, joem joem@martindale-electric.co.uk wrote:
On Tue, 2013-11-05 at 12:04 +0000, luke.leighton wrote:
this is mainly a question for joe (and anyone else with schematics review experience!)
the goal is to provide dual-power for the ATSAM4S. atmel recommend using 2 diodes however the voltage for the IO needs to be above 3.0v in order to run USB, the AXP209 can only output 3.3v max and a diode would suck 0.7v off of that.
so i've been advised to use a MOSFET instead, and need to check it's going to work. so here's the schematic that needs checking:
hmmmp....
I just scanned it again - notice a problem - the WNM2306 is an n-FET. You need a p-FET with similar ratings to work it correctly.
you missed the message saying "please disregard". i've already replaced this with an SS12.