Patent ID: 7035069

Claim:
A communication semiconductor integrated circuit device comprising: a transmission unit formed on a semiconductor chip, and forming a transmission signal to be provided to an antenna; a reception unit formed on the semiconductor chip, and receiving a receiving signal from the antenna and forming a signal which has a frequency lower than that of the receiving signal, wherein the reception unit includes a low noise amplifier transistor receiving the receiving signal; a terminal formed on the semiconductor chip, and coupled to the low noise amplifier transistor; a first voltage line arranged to be supplied with a first voltage having a first potential; a second voltage line arranged to be supplied with a second voltage having a second potential that is different from the first potential; and a protection unit formed on the semiconductor chip, and coupled to the low noise amplifier transistor, to the first voltage line, to the second voltage line and the terminal, wherein the protection unit includes a first protection circuit which is coupled between the first voltage line and the terminal and which allows an electric current to flow from the first voltage line to the terminal at a protection time against an electrostatic breakdown, and a second protection circuit which is coupled between the second voltage line and the terminal and which allows an electric current to flow from the terminal to the second voltage line at a protection time against an electrostatic breakdown, the first and second protection circuits being directly electrically connected in common to the terminal.