Abstract: A control chip including a first pin, a second pin, a trigger circuit and a control circuit is provided. The first pin is configured to couple to a connection port. The second pin is configured to couple to the connection port. The trigger circuit sets a level of the second pin to a second level when the connection port is coupled to an external electronic device and the level of the second pin is equal to a first level. The control circuit maintains the level of the second pin at the second level when a voltage of the first pin is equal to a pre-determined voltage.