Patent ID: 7986927

Claim:
A semiconductor integrated circuit device, comprising: a first terminal coupled to an antenna; a plurality of second terminals coupled to a transmitting circuit; a switching transistor circuit placed between the first terminal and the second terminals respectively and switching a connection between the first terminal and the second terminal; and a booster circuit generating and outputting a boost voltage higher than a control signal of the switching transistor circuit, wherein the booster circuit includes: a control terminal to which the control signal of the switching transistor circuit is input; a boost terminal that outputs a boost voltage; and a boost part which takes in a transmission signal output via the switching transistor circuit when the control signal is input to the control terminal, and which generates a boost voltage higher than a voltage level of the input control signal and applies the same to a control terminal of the switching transistor circuit via the boost terminal; and a loss improving resistor coupled between the second terminal and the boost terminal and reducing a voltage attenuation of the transmission signal wherein the boost part includes: a first capacitive element whose one connection portion is coupled to the second terminal; a first resistor whose one connection portion is coupled to the other connection portion of the first capacitive element; a first diode whose cathode is coupled to the other connection portion of the first resistor; a second capacitive element whose one connection portion is coupled to an anode of the first diode; a second resistor whose one connection portion is coupled to the other connection portion of the first capacitive element; a second diode whose anode is coupled to the other connection portion of the second resistor and whose cathode is coupled to the other connection portion of the second capacitive element; and a third resistor whose one connection portion is coupled to the control terminal and the anode of the first diode and whose the other connection portion is coupled to the boost terminal; wherein the loss improving resistor is coupled between the other connection portion of the first capacitive element and the boost terminal.