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OwnerRaul-Adrian Cernea, Rushyah Tang +3inventors
InventorsRaul-Adrian Cernea, Rushyah Tang, Douglas Lee, Chi-Ming Wang, Daniel Guterman
Estimating the term…
Floating gate memories such as EEPROM and flash EEPROM have the memory state of a memory cell thereof determined by sensing the conduction current of the cell. Inherent noise fluctuations in the conduction current during sensing are canceled out by averaging the sensing over a predetermined period of time. In one embodiment, as an integral part of the averaging process, the averaged conduction current is obtained directly as a digital memory state. Accuracy in sensing is therefore greatly improved by avoiding sensing noise with the current and avoiding having to resolve its memory state in the analog domain by comparison with another noisy reference current. In another embodiment, conventional sensing techniques are improved when sensing is made by comparison with a reference current by means of a symmetric, switched or non-switched capacitor differential amplifier. The improved sensing accuracy allows higher resolution of conduction states, thereby allowing a cell to store substantially more than one bit of information.
A non-volatile memory comprising an array of memory cells, each memory cell having a source, a drain, a floating gate and a control gate, said floating gate receptive to variable amount of charges being stored therein for designating a plurality of memory states, said non-volatile memory further comprising:
In a non-volatile memory comprising an array of memory cells, each memory cell having a source, a drain, a floating gate and a control gate, said floating gate receptive to variable amount of charges being stored therein for designating a plurality of memory states, a method of sensing the memory state of a memory cell, comprising:
A method of sensing the memory state of a memory cell as in 18, wherein said measuring include comparing said source-drain current with a reference current over said predetermined period of time.
Dependencies are inferred from the claim text.