Patent ID: 6831488
Filing Date: 2004-12-14
Classification: H03K,H04L

Abstract:
A semiconductor integrated circuit device, comprising:a power supply line transmitting a power supply voltage; an input terminal; an output terminal; a control terminal; a ground terminal; a first MOS transistor including a first main electrode connected to said power supply line transmitting a power supply voltage, a second main electrode connected to said input terminal, and a first gate electrode, said first MOS transistor flowing a pull-up current from said first main electrode to said second main electrode in a first on-state where said first MOS transistor is in an on-state when no input signal is input to said input terminal; a second MOS transistor including a third main electrode connected to said input terminal, a fourth main electrode connected to said ground terminal, and a second gate electrode, said second MOS transistor flowing a pull-down current from said third main electrode to said fourth main electrode in a second on-state where said second MOS transistor is in an on-state when no input signal is input to said input terminal; an input/output logic changing circuit including a first terminal connected to said input terminal, a second terminal connected to said output terminal, and a third terminal; and a control signal line including one end connected to said control terminal and the other end connected to said first gate electrode, said second gate electrode and said third terminal, said control signal line transmitting a control signal thereon to said other end, wherein when said control signal has a first level, said first MOS transistor and said second MOS transistor are placed in said first on-state and a second off-state where said second MOS transistor is in an off-state, respectively, when said control signal has a second level, said first MOS transistor and said second MOS transistor are placed in a first off-state where said first MOS transistor is in an off-state and said second on-state, respectively, and when an input signal is input to said input terminal, said input/output logic changing circuit determines a logic level of an output signal based on said input signal and said control signal to thereby output said output signal to said output terminal.