Given this restriction can anyone recommend a small board that can regulate 12v to 5v and 3.3v.
I will be driving motors and steppers at 12 v and want to use one source for that and the BBB. Thanks Eric On Mon, Feb 24, 2014 at 2:15 PM, Gerald Coley <[email protected]>wrote: > If you apply power to an I/O pin without power on the power rails of the > processor, that is basically what you are doing! > > Read the datasheet for the processor and look at the > power sequencing required by the designers of the processor. > > http://www.ti.com/product/am3358 > > Gerald > > > > On Mon, Feb 24, 2014 at 12:11 PM, <[email protected]> wrote: > >> Gerald Coley <[email protected]> wrote: >> > [-- text/plain, encoding quoted-printable, charset: ISO-8859-1, 56 >> lines --] >> > >> > Not really. The idea of powering a chip via an I/O pin will >> > always cause damage. It means voltage as specified by the datasheet of >> > the component. >> > >> I don't aim to 'power' it via the I/O pin! Maybe that's your way of >> saying it but it's a very odd way. The likelihood is that there will >> be a biggish resistor in series with the input to limit current and >> there will probably also be some clamping diodes or maybe a buffer >> amplifier but whatever you do there *cannot* be 'no voltage'. >> >> What I'm asking really is what will be tolerated with no problems, >> every chip spec I have ever seen specifies some sort of minimum, not >> zero. >> >> So what is the "voltage as specified by the datasheet of >> the component."? That's what I'm asking really, I'll go and look at >> the processor spec sheet. >> >> >> > It is your choice, but, it will cause damage to the part. >> > >> > If you power a system form one power source, it is not hard to do. Using >> > two power sources that are not synchronized with each other, that is >> where >> > the issue comes into play. >> > >> Real systems don't come like that! Are you going to turn off every >> single thing in you car/boat/house etc. just so you can power down a >> Beaglebone monitor? >> >> -- >> Chris Green >> ยท >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- Eric Palmer -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
