Patent ID: 7142040

Claim:
A stabilized power supply circuit comprising: a charge pump power supply circuit including a plurality of switches and a capacitor, wherein, through combination of selective on and off operations of the individual switches, the charge pump power supply circuit accumulates electric charge in the capacitor and outputs, as output voltage, voltage generated upon accumulation of electric charge; and an error amplifier comparing the output voltage and a predetermined reference voltage and outputting an error signal on the basis of the difference between the output voltage and the reference voltage, wherein at least one of the switches of the charge pump power supply circuit is constituted by a field effect transistor; a current source is connected in series to a gate of the field effect transistor; and the current source is controlled in accordance with the error signal output from the error amplifier, whereby a period during which electric charge is charged into or discharged from the gate is controlled in accordance with the error signal in order to maintain the output voltage constant.