Patent ID: 6473338
Filing Date: 2002-10-29
Classification: G11C

Abstract:
An analog voltage supply circuit for a non-volatile memory comprising:a write voltage generation circuit which generates a write voltage that is applied to a control gate of a memory cell in said non-volatile memory during a write operation, based on an input analog voltage; a verify voltage generation circuit which generates a verify voltage that is applied to said control gate during a verify operation, based on said input analog voltage; a source voltage generation circuit having an inverting amplifier which generates a source voltage that is applied to a source of said memory cell during the write operation, wherein said source voltage is changed by varying a gain of said inverting amplifier responsive to a control signal; a multi-level sense amplifier which compares a current mirror ratio current of a memory cell drain current with a reference comparison current during the verify operation; a counter decoder circuit which outputs a signal equivalent to a number of write pulses applied to said memory cell; a comparison circuit which compares an output of said multi-level sense amplifier with the number of write pulses determined by said counter decoder circuit; and an up-down shift register circuit which shifts a level of said control signals based on a comparison result provided by said comparison circuit.