Device and method for operating same

Disclosed are a device and a method for operating the same. An embodiment of the present invention comprises: an interface unit formed on one side of a device body and including a USB port to which a cable of an external device is connected; a sensing unit which detects that a cable is connected to or disconnected from the USB port; and a control unit which initializes the output current of the USB port to a defined current level, determines an operation mode of the device body, corresponding to a connection of an external device, on the basis of a voltage applied to a particular pin of the USB port when the external device is connected to the USB port, and controls the output current of the USB port according to the determined operation mode. In addition, when the cable is disconnected from the USB port, the control unit resets the output current of the USB port to the defined current level again.