Patent ID: 7193471

Claim:
A power module, comprising: an amplification means for amplifying a first signal (Pin) to be amplified; a bias means for supplying bias voltages to the amplification means; a detection means for detecting an output power of the amplification means and for generating a second signal (Vsns) which indicates the output power the amplification means; a comparison means for comparing the second signal with a third signal (Vramp) which designates the output power of the amplification means and for supplying a forth signal (Vapc) to the bias means; a first power source voltage terminal which is coupled to the detection means and supplies a first operational power source voltage (Vreg) to the detection means; and a second power source voltage terminal which is coupled to the amplification means supplies a second operational power source voltage (Vdd) different from the first operational power source voltage (Vreg), wherein the detection means further comprising a detection transistor (Q 1 ) which is connected to a first resistor (R 2 ) coupled between an output terminal of the detection transistor (Q 1 ) and the first power source voltage terminal and which receives a fifth signal related to the output power from the amplification means, and wherein the first operational power source voltage(Vreg) is set so as to be less in voltage variation than the second operational power source voltage(Vdd).