[beagleboard] Is it safe to power Beagleboard XM Rev B with 5V Supply of PC ATX SMPS?

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1

Hello,

Is it safe to power Beagleboard XM rev B with the +5V DC output of PC ATX SMPS directly or should a linear regulated 5V supply be used instead to be on the safer side?

In other words, does the Beagleboard XM have circuitry to handle 5V SMPS supply input ?

I want to be be very sure as the last thing I want is a conked off Beagleboard.

I could use the +12V DC of PC SMPS and put a 5V regulator like L78S05. But that would mean additional circuitry, a big heat sink & lot of power wastage.

Thanks & Regards,
Tushar

2

Well, the "wall-wart" supplies recommended for the BeagleBone are all
switching-mode power supplies, so the ATX supply should work just fine.

Note that you do need to have enough load on the supply for it to
operate properly, there are different 'flavors' of ATX supplies and they
have different minimum load specifications. Also note that the 5V aux.
supply (that is on all the time) is rated for 2A on almost all recent
ATX supplies. I plan on running the 'Bone off the 5V aux. rail so it's
on all the time, and using the switched 5V and 12V to drive my 3D
printer so "machine power" is only active when I'm printing something.
I haven't done this yet with the 'Bone, but it's how I had the Arduino
controller hooked up, and it worked fine.

Also, if you're _only_ using the 5V aux supply for the 'Bone, you don't
need to worry about turning the ATX supply on or having a proper load on
the higher-current 5V and 12V lines. Just hook up two wires and you're
done. :slight_smile:

3

As I remember , BeagleBoard Xm will have a limit of power protecter . over 5.3v or lower than 4.xv (not clear about this )
You will not be able to power up the board . TPS65930 will not power up the omap3730
ATX power 5V will always have the very big ripple .

If you can boot up normally , ignore this .

4

Thanks Charles & Liyoshi for your inputs!

Btw. , Are there any chips which will specifically remove the high ripples @5V yet allow around 1.5 A current to flow ? Would a low ESR 10uF/100uF/1000uF cap between SMPS & Beagleboard XM do the job?

Best Regards,
Tushar

5

I’m running my Beaglebones off the +5V line of a ATX Power supply with no problems. I have not tried the standby power line, but according to wikipedia http://en.wikipedia.org/wiki/ATX, the standby +5V (Vsb) is spec’ed to a peak to peak ripple of 50mV, and the same as the +5 VDC (main 5V line) from the ATX supply. So, there SHOULD BE NO PROBLEMS with ripple.

I’ve had my Beaglebone(s) (yeah, a few of them) powered on the ATX supply for weeks now without any problems.

Paul Tan.
http://www.exadler.com
http://exadler.blogspot.com

6

We use ATX power supplies to run our burnin racks.

Gerald

7

Thanks Paul & Gerald for the info & links!

Best Regards,
Tushar