Two options are available to power up the SAMA5D2-ICP board:
The +5V from the wall adapter is protected through an NCP349 positive overvoltage controller switch. The controller is able to disconnect the system from its output pin when incorrect input operating conditions are detected (5.83V max).
The USB-powered operation comes from the USB J-Link-OB port connected to a PC or a 5V DC supply. The USB supply is sufficient to power the board in most applications. It is important to note that when the USB supply is used, the USB port has limited power. If the USB host port is required for the application, it is recommended to use the external DC supply.
The red D3 ON LED indicates the presence of a 5V power supply from the wall adapter or from USB.
USB-powered operation eliminates additional wires and batteries. It is the preferred mode of operation for any project that requires only a 5V source at up to 500 mA.