Gerald Coley <[email protected]> wrote: > [-- text/plain, encoding quoted-printable, charset: ISO-8859-1, 73 lines --] > > BUT, there is no I/O supply if the I/O supply is not turned on. The I/O > supply has to be there. > If it's not turned on then it's 0 volts isn't it? Power supplies don't go open circuit when they're turned off so the 3.3 volt line will be sitting at close to 0 volts and you'd need to pump a lot of current into it to drag it away from there. There will be 10k or more of series resistance in the inputs so we're only talking about less than 1mA of current going through the clamping diodes, that's not going to move the supply line voltage by anything much.
> Look, go ahead and ignore me if you like. But I talk to the designers of > this device daily and support hundreds of customers daily. And I > see boards come into the RMA department all the time with blown processors > due to this issue. The power sequencing diagram is there for a reason due > to the multiple voltage rails inside this device. Violate the > power sequencing and you will have issues. > I'm not violating the power sequencing, I'm obeying it carefully by ensuring that there's no voltage on the inputs until the 3.3 volt I/O supply appears. -- 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.
