Patent ID: 6836436
Filing Date: 2004-12-28
Classification: G11C

Abstract:
A voltage generator for a flash memory device, comprising:a low-voltage detector for comparing cell currents of different states of two flash memory cells to detect variation in the power supply voltage; and a high voltage generating means for comparing cell currents of different states of at least two or more flash memory cells to generate at least one or more given high voltages, wherein the high voltage generating means includes: at least one or more charge pump circuits for pumping the power supply voltage to a given high voltage and regulating the power supply voltage to a given level; at least one or more voltage dividers for dividing outputs of the charge pump circuits, respectively; an over-erased flash memory cell; at least one or more programmed flash memory cells; and at least one or more comparators for comparing cell currents of the programmed flash memory cells, respectively, based on the cell current of the over-erased flash memory cell and for controlling the charge pump circuits depending on the comparison result.