SWITCH CONTROL CIRCUIT, SEMICONDUCTOR DEVICE AND RADIO COMMUNICATION DEVICE

PROBLEM TO BE SOLVED: To switch between a plurality of radio sections without increasing the number of terminals.SOLUTION: A switch control circuit 3 includes: a serial-parallel converter 5 for converting a serial switching control signal to switch a switch circuit to a first parallel switching control signal in synchronization with a clock signal; first to third terminals for inputting types of signals depending on whether or not the serial-parallel converter performs the serial-parallel conversion; a selector 6 for selecting either of the first parallel switching control signal converted in the serial-parallel converter and a second parallel switching control signal input into the second and third terminals; a driver circuit 8 for converting a potential level of the signal selected by the selector; and a tristate buffer 10 having input terminals connected to the serial-parallel converter and an output terminal connected to the second terminal, capable of setting the output terminal at a high impedance, and controlled not to allow a current to flow from the second terminal to a power line of the tristate buffer via the output terminal of the tristate buffer when the second terminal is at a high potential.