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BBB input voltage

Posted: Fri Feb 27, 2009 12:09 pm
by m_elias
I want to clarify how much voltage the regulator can handle on the BBB revD. On page 2 of the pdf instructions it talks about a 5-9V external PS and on the schematic on page 5 it's labeled as 5-12V. I realize that higher voltage and/or higher current equals higher heat dissipation. My application uses very little current. Is 12V the limit or could a guy get away with 15V?

Re: BBB input voltage

Posted: Fri Feb 27, 2009 1:00 pm
by floresta

The L4931 voltage regulator can handle up to 20v and the 47uF input capacitor (at least the one on my board) is rated at 25v so you should be OK with 15v input. As you mentioned it is the heat that is of concern but most regulators will just shut down if they get too hot. Paul will probably answer you and confirm or correct my diagnosis when he gets back from his day job.


Re: BBB input voltage

Posted: Sat Feb 28, 2009 1:41 am
by paul
Thanks for the reply floresta,

It's all correct - the datasheet says 20V, I just listed 12V because of power dissipation issues and because I like to be conservative. 15V should be fine, but if you start drawing much current from it, it will shut down fairly soon.