Charge packet metering for coarse/fine programming of non-volatile memory
AssigneeSanDisk Corporation
InventorsDaniel C. Guterman, Nima Mokhlesi, Yupin Fong
Life of this patent
Estimating the term…
Abstract
A non-volatile memory device is programmed by first performing a coarse programming process and subsequently performing a fine programming process. The coarse/fine programming methodology is enhanced by using an efficient verification scheme that allows some non-volatile memory cells to be verified for the coarse programming process while other non-volatile memory cells are verified for the fine programming process. The fine programming process can be accomplished using current sinking, charge packet metering or other suitable means.
Claims11
An apparatus for programming, comprising:
- a non-volatile storage element having a control terminal;
- and
- an individually switchable charge packet metering system in communication with said control terminal, said individually switchable charge packet metering system includes a charge storage device, said individually switchable charge packet metering system is individually switched to provide a particular metered charge by discharging said charge storage device to said control terminal to program said non-volatile storage element in a fine programming mode without providing said particular metered charge to program non-volatile storage element in a coarse programming mode.
An apparatus for programming, comprising:
- a set of non-volatile storage elements having control terminals;
- and
- an individually switchable charge packet metering system in communication with said control terminals, said individually switchable charge packet metering system is individually switched to provide a particular metered charge to program non-volatile storage elements in a fine programming mode without providing said particular metered charge to program non-volatile storage elements in a coarse programming mode, said switchable charge packet metering system comprises a charge packet metering circuit for each bit line of a set of bit lines for said set of non-volatile storage elements, each charge packet metering circuit can be separately switched.
An apparatus for programming, comprising:
- a set of non-volatile storage elements having control terminals;
- and
- an individually switchable charge packet metering system in communication with said control terminals, said individually switchable charge packet metering system is individually switched to provide a particular metered charge to program non-volatile storage elements in a fine programming mode without providing said particular metered charge to program non-volatile storage elements in a coarse programming mode,
- said switchable charge packet metering system comprises a source, a first switch in communication with said source and a first charge storage device, said first charge storage device is in communication with said first switch and a first control line for a first non-volatile storage element, said first switch selectively allows said source to charge said first charge storage device, said switchable charge packet metering system further comprises a second switch, said second switch is in communication with said control line and said charge storage device, and said second switch selectively connects said charge storage device to said control line when said non-volatile storage element is in said fine programming mode.
Dependencies are inferred from the claim text.