I bought a AC to DC adapter from the market with the following
output rating: 5V - 2A. When I tested this adapter with multimeter, it
was giving 5.3 V as output. In the Electrical Specifications section
in the reference manual of Beagleboard xM I found that the voltage
should not exceed 5.2 V. But maximum voltage without damage is given
as 12 V.
So my query is, it advisable to use this adapter as power supply or
should I by a new one, or cascade a 5V Voltage regulator manually.
Thanking in Advance
IIIT Hyderabad, India
You need to measure the voltage under load. The big issue is the USB ports. They can’t handle past 6V, so as long as it does not exceed that, then you are OK. As long as the detect circuit does not trip, you should be able to operate. The regulators on the board can handle the 12V, but the USB FETs are the real issue.
I have same problem, I also tried two adapters with 5V 3A rating. Both
the adapters give more than 5.3V some times and reset beagleboard &
red led of starts to glow.
Actually as soon as voltage more than 5.3V beagleboard-XM over voltage
protection cut-off supply, till voltage becomes lower than 5.3V. Thow
most adapters I found are not suitable for beagleboard. It require 5V
+/-5% tolerance adapter and most adapter fail to meet this.
You should not try removing this protection, try to make your own 5 V
regulated supply, if not using usb ports you will be able to power it
from max. 350mA current.
I suggest you get a good power supply. Protection is there for a reason. If this blows up the board then it is on you to cover repair cost If you remove the protection. removing th eprotection voids the warranty is now void.
I have made my own power supply from LM2576. It can give 5V +/-4% upto
It is simple to make. Working fine, LM2576 is a good power switcher,
input can to switcher can vary from 7V to 40 V(HV version can handle
even higher input). Works very cooler compare to 7805.