5v power supply in beaglebone

Is there any way to connect the beaglebone to the 5v power supply and run it without the usb connector??
When I use the 5v power supply connector the leds start to blink (so the system is booting) but the beaglebone reboot constantly.
I try it with the 2 beaglebone (rev A5) and in both cases the same thing does occur.
Thanks in advance.

Solved! 1.5A at least.

2012/7/20 Rai32 <ramon.benavent@gmail.com>