Patent ID: 6803807
Filing Date: 2004-10-12
Classification: H02M

Abstract:
A negative voltage output charge pump circuit comprising:a capacitor that, while being charged, receives, at one end thereof, a reference voltage and receives, at another end thereof, a positive voltage relative to the reference voltage and that, while being discharged, has said another end thereof conducting to the reference voltage and has said one end thereof conducting to an output terminal; a first switching device that is kept on while the capacitor is being charged so as to apply the reference voltage to said one end of the capacitor; and a second switching device that is kept on while the capacitor is being discharged so as to make said one end of the capacitor conduct to the output terminal, wherein at least one of the first and second switching devices is of a depletion type, wherein the switching devices are formed on a well that is electrically separated from a substrate.