An apparatus for controlling a switching circuit in a portable terminal, the apparatus comprising: a connector interface unit, connected with an external device (200, 300), for transmitting signals between the portable terminal and the external device (200, 300); a switching circuit for connecting/disconnecting signal lines with the connector interface unit and for establishing a signal path between the external device (200, 300) and a corresponding internal module to perform data communication; a signal detector for detecting a signal generated when the external device (200, 300) is connected to the connector interface unit to output a first detected value corresponding to the detected signal, and for detecting an external event from the external device (200, 300) when the external device (200, 300) is connected to the connector interface unit and the portable terminal is operated in a communication mode with the external device (200, 300) to output a second detected value corresponding to the detected external event; and a controller for identifying the type of the external device (200, 300) according to the first detected value when the external device (200, 300) is connected to the connector interface unit, for activating the communication mode of the portable terminal with the external device (200, 300) according to the identified type of the external device (200, 300), and for switching between active and sleep modes of the switching circuit according to the second detected value when the external device (200, 300) is connected to the connector interface unit and the portable terminal is operated in the communication mode with the external device (200, 300), wherein during the active mode, the signal path between the external device (200, 300) and the corresponding internal module is established, and during the sleep mode, the signal path between the external device (200, 300) and the corresponding internal module is broken. a connector interface unit, connected with an external device (200, 300), for transmitting signals between the portable terminal and the external device (200, 300); a switching circuit for connecting/disconnecting signal lines with the connector interface unit and for establishing a signal path between the external device (200, 300) and a corresponding internal module to perform data communication; a signal detector for detecting a signal generated when the external device (200, 300) is connected to the connector interface unit to output a first detected value corresponding to the detected signal, and for detecting an external event from the external device (200, 300) when the external device (200, 300) is connected to the connector interface unit and the portable terminal is operated in a communication mode with the external device (200, 300) to output a second detected value corresponding to the detected external event; and a controller for identifying the type of the external device (200, 300) according to the first detected value when the external device (200, 300) is connected to the connector interface unit, for activating the communication mode of the portable terminal with the external device (200, 300) according to the identified type of the external device (200, 300), and for switching between active and sleep modes of the switching circuit according to the second detected value when the external device (200, 300) is connected to the connector interface unit and the portable terminal is operated in the communication mode with the external device (200, 300),