Patent ID: 6151255
Filing Date: 2000-11-21
Classification: G11C

Abstract:
A flash memory which is electrically erasable programmable and has a negative voltage generator for data erasure, wherein said negative voltage generator comprises:a charge pump for pumping a negative charge;a regulator for regulating the level of an output voltage from said charge pump according to the level of a supply voltage including,a reference voltage generator for generating a reference voltage according to the level of said supply voltage;a comparison voltage generator for generating a voltage to be compared with said reference voltage from said reference voltage generator, according to the level of the output voltage from said charge pump; anda comparator for comparing said reference voltage from said reference voltage generator and said comparison voltage from said comparison voltage generator with each other and feeding the compared result back to said charge pump; anda negative voltage supply for supplying a voltage of the level regulated by said regulator to a gate of a memory cell transistor;whereby, for a data erase operation of said flash memory, an output voltage from said negative voltage supply is applied to said gate of said cell transistor, said supply voltage is applied to a source of said cell transistor while the drain of said memory cell transistor floats.