Patent ID: 7091749

Claim:
A cellular phone comprising: an audio output portion, an audio input portion, an operation switch, a display portion, the display portion comprising: first and second transistors each comprising an input terminal electrically connected to a first electric power source; third and fourth transistors each comprising an input terminal electrically connected to a second electric power source; a voltage compensator circuit comprising: a fifth transistor comprising an output terminal electrically connected to a gate electrode of the first transistor and a gate electrode of the second transistor; and a capacitor between the output terminal of the fifth transistor and an output terminal of the first transistor; a first signal input portion for inputting a first signal to a gate electrode of the third transistor and a gate electrode of the fourth transistor; a second signal input portion for inputting a second signal to an input terminal of the fifth transistor; and a signal output portion, wherein each of the first through the fifth transistors have the same conductivity type, wherein the output terminal of the first transistor and an output terminal of the third transistor are electrically connected, wherein an output terminal of the second transistor and an output terminal of the fourth transistor are electrically connected to the signal output portion, wherein a gate electrode of the fifth transistor is electrically connected to the first electric power source or to a third electric power source, and wherein the voltage compensator circuit compensates for amplitude attenuation of a signal output from the signal output portion.