Abstract: A semiconductor device is provided in which power consumption is reduced and an increase in circuit area is inhibited. The semiconductor device includes a high frequency amplifier circuit, an envelope detection circuit, and a power supply circuit. The power supply circuit has a function of supplying a power supply potential to the high frequency amplifier circuit, an output of the high frequency amplifier circuit is connected to the envelope detection circuit, and an output of the envelope detection circuit is connected to the power supply circuit. The power supply circuit can reduce the power consumption by changing the power supply potential in accordance with the output of the high frequency amplifier circuit. The use of an OS transistor in the envelope detection circuit can inhibit an increase in circuit area.

Abstract: To provide an ink jet recording apparatus in which the residual vibration of any ink can be prevented to avoid the spread of the ink at an opening portion and to perform the continuous discharge of the ink stably. An ink-jet recording apparatus includes a recording head including a pressure chamber and a nozzle, the pressure chamber containing ink, the nozzle communicating with the pressure chamber and having an opening portion formed therein to discharge the ink, a piezoelectric element forming part of the pressure chamber, and a driving signal producing section producing a driving signal to be input to the piezoelectric element to change the volume of the pressure chamber.

Abstract: To provide an ink jet recording apparatus in which the residual vibration of any ink can be prevented to avoid the spread of the ink at an opening portion and to perform the continuous discharge of the ink stably. An ink-jet recording apparatus includes a recording head including a pressure chamber and a nozzle, the pressure chamber containing ink, the nozzle communicating with the pressure chamber and having an opening portion formed therein to discharge the ink, a piezoelectric element forming part of the pressure chamber, and a driving signal producing section producing a driving signal to be input to the piezoelectric element to change the volume of the pressure chamber.