Patent ID: 7808269

Claim:
A semiconductor integrated circuit comprising: a first transistor of a first conductivity type, which has a current path with one end connected to a first power supply, and has a control terminal to which a first control signal is input; a second transistor of the first conductivity type, which has a current path with one end connected to the first power supply, and has a control terminal to which a second control signal is input; a first resistor element having one end connected to the other end of the current path of the first transistor, and having the other end connected to a first output terminal; a second resistor element having one end connected to the other end of the current path of the second transistor, and having the other end connected to a second output terminal; a third transistor of a second conductivity type, which has a current path with one end connected to the other end of the first resistor terminal, and has a control terminal to which a third control signal is input; a fourth transistor of the second conductivity type, which has a current path with one end connected to the other end of the second resistor terminal, and has a control terminal to which a fourth control signal is input; a fifth transistor of the second conductivity type, which has a current path with one end connected to the other end of the current path of the third transistor and to the other end of the current path of the fourth transistor, and with the other end connected to a second power supply, and has a control terminal to which a fifth control signal is input; a control signal generating circuit which sets, at least at a time of a first state, the first and fifth control signals at a first voltage level, and the second, third and fourth control signals at a second voltage level, and sets, at a time of a second state, the first to fourth control signals at the first voltage level, and the fifth control signal at an arbitrary voltage level; a first variable terminating resistor including a plurality of transistors each having a current path with one end connected to the first power supply and having a control terminal to which the first control signal is input, and a plurality of resistor elements each having one end connected to the other end of the current path of the associated one of the plurality of the transistors and having the other end connected to the first output terminal; and a second variable terminating resistor including a plurality of transistors each having a current path with one end connected to the first power supply and having a control terminal to which the second control signal is input, and a plurality of resistor elements each having one end connected to the other end of the current path of the associated one of the plurality of the transistors and having the other end connected to the second output terminal.