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[Question] About mbed regulated voltage output PIN 39 - VU

Topic last updated 19 Sep 2012, by chris t. 1 reply
Nuno Sarmento
19 Sep 2012

Hi everyone,

I've got a question. Hope it's not to silly but from the datasheet i can't get this information.

When i plug my mbed to a power source USB/DC batteries , what should be the output from pin 39? I get 1.9V and sometimes a little bit more but never 5V as the schematic on website refers to.

I've tested this on 3 different mbeds and the output is the same on all of them.

I don't know if this should happen because has I see you can supply standard IC power (+5V) to your circuit from this mbed output (PIN39)

Thanks for support,

Samuel Matildes

chris t
19 Sep 2012

Hi its not a silly question this one has bitten me before this is a 5v supply when the usb cable is connected to a usb feed i.e your computer when programming

this note is taken from the handbook •5.0v from USB available on VU (only available when USB is connected!)

hope this helps

chris