A novel sense amplifier for flexible voltage operation NAND flash memories

This paper proposes a new bit-by-bit verify circuit for application in NAND flash memories. The Sense Amplifier (S/A) employed confers two benefits: flexible power supply voltage (ex. 3 V or 5 V) operation with a high noise immunity and an intelligent page copy function. The benefits are very useful to the flash memory card or system and accelerate the replacement of magnetic memories by flash memories. The S/A has been successfully implemented in the commercial version of the 32 Mbit NAND-EEPROM, in which the S/A is newly introduced in comparison with the prototype version.