Patents by Inventor Mohan V. Dunga
Mohan V. Dunga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11031085Abstract: A non-volatile memory system comprises a memory structure and a control circuit connected to the memory structure. The memory structure includes one or more planes of non-volatile memory cells. Each plane is divided into a plurality of partial planes. The control circuit is configured to write to and read from the memory cells by writing a partial page into a particular partial plane and reading the partial page from the particular partial plane using a set of parameters optimized for the particular partial plane.Type: GrantFiled: June 9, 2020Date of Patent: June 8, 2021Assignee: SanDisk Technologies LLCInventors: Mohan V Dunga, Pitamber Shukla
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Publication number: 20200303010Abstract: A non-volatile memory system comprises a memory structure and a control circuit connected to the memory structure. The memory structure includes one or more planes of non-volatile memory cells. Each plane is divided into a plurality of partial planes. The control circuit is configured to write to and read from the memory cells by writing a partial page into a particular partial plane and reading the partial page from the particular partial plane using a set of parameters optimized for the particular partial plane.Type: ApplicationFiled: June 9, 2020Publication date: September 24, 2020Applicant: SanDisk Technologies LLCInventors: Mohan V. Dunga, Pitamber Shukla
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Patent number: 10741251Abstract: A non-volatile memory system comprises a memory structure and a control circuit connected to the memory structure. The memory structure includes one or more planes of non-volatile memory cells. Each plane is divided into a plurality of partial planes. The control circuit is configured to write to and read from the memory cells by writing a partial page into a particular partial plane and reading the partial page from the particular partial plane using a set of parameters optimized for the particular partial plane.Type: GrantFiled: April 17, 2018Date of Patent: August 11, 2020Assignee: SanDisk Technologies LLCInventors: Mohan V Dunga, Pitamber Shukla
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Publication number: 20190180822Abstract: A non-volatile memory system comprises a memory structure and a control circuit connected to the memory structure. The memory structure includes one or more planes of non-volatile memory cells. Each plane is divided into a plurality of partial planes. The control circuit is configured to write to and read from the memory cells by writing a partial page into a particular partial plane and reading the partial page from the particular partial plane using a set of parameters optimized for the particular partial plane.Type: ApplicationFiled: April 17, 2018Publication date: June 13, 2019Applicant: SanDisk Technologies LLCInventors: Mohan V Dunga, Pitamber Shukla
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Patent number: 9349452Abstract: A non-volatile storage system includes a plurality of groups of connected non-volatile storage elements. Each group comprises multiple connected data non-volatile storage elements and multiple select gates on a common side of the data non-volatile storage elements. The multiple select gates comprise a first select gate and a second select gate. The first select gate has a first threshold voltage for a first subset of the groups and a second threshold voltage for a second subset of the groups due to active area implantation for the second subset of groups that causes the second threshold voltage to be lower than the first threshold voltage. The second select gate of each group has a programmable threshold voltage. Each of the plurality of bit lines are connected to multiple groups of connected non-volatile storage elements.Type: GrantFiled: March 7, 2013Date of Patent: May 24, 2016Assignee: SanDisk Technologies Inc.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Patent number: 9165656Abstract: A non-volatile storage system is disclosed that includes pairs (or another number) of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. By sharing bit lines, less bit lines are needed in the storage system. Using less bit lines reduces the space needed to implement the storage system. Each NAND string will have two drain side select gates. The non-volatile storage system will have two drain side selection lines each connected to one of the two drain side select gates so that the NAND strings sharing a bit line can be individually selected. To allow proper selection of a NAND string using the select gates, the select gates will be subjected to non-volatile programming in order to set the threshold voltage of the select gates to an appropriate level.Type: GrantFiled: March 11, 2013Date of Patent: October 20, 2015Assignee: SanDisk Technologies Inc.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Patent number: 9082502Abstract: In a block of non-volatile memory, bit line current increases with bit line voltage. For current sensing memory systems, average bit line current during a sensing operation need only exceed a certain threshold amount in order to produce a correct result. For the first word lines being programmed in a block, memory cells connected thereto see relatively low bit line resistances during verify operations. In the disclosed technology, verify operations are performed for these first programmed word lines with lower verify bit line voltages in order to reduce excess bit line current and save power. During read operations, this scheme can make threshold voltages of memory cells connected to the lower word lines appear lower. In order to compensate for this effect, various schemes are disclosed.Type: GrantFiled: October 10, 2013Date of Patent: July 14, 2015Assignee: SANDISK TECHNOLOGIES INC.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Patent number: 9076544Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential.Type: GrantFiled: November 12, 2012Date of Patent: July 7, 2015Assignee: SANDISK TECHNOLOGIES INC.Inventors: Nima Mokhlesi, Mohan V. Dunga, Man Mui
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Patent number: 9047971Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential.Type: GrantFiled: May 29, 2014Date of Patent: June 2, 2015Assignee: SanDisk Technologies, Inc.Inventors: Nima Mokhlesi, Mohan V. Dunga, Man Mui
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Publication number: 20150103595Abstract: In a block of non-volatile memory, bit line current increases with bit line voltage. For current sensing memory systems, average bit line current during a sensing operation need only exceed a certain threshold amount in order to produce a correct result. For the first word lines being programmed in a block, memory cells connected thereto see relatively low bit line resistances during verify operations. In the disclosed technology, verify operations are performed for these first programmed word lines with lower verify bit line voltages in order to reduce excess bit line current and save power. During read operations, this scheme can make threshold voltages of memory cells connected to the lower word lines appear lower. In order to compensate for this effect, various schemes are disclosed.Type: ApplicationFiled: October 10, 2013Publication date: April 16, 2015Applicant: Sandisk Technologies, Inc.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Publication number: 20140269082Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line. One set of embodiments avoid unwanted boosting during read operations by keeping the channels of the memory cells connected to word lines on the drain side of the selected word line biased at a fixed potential.Type: ApplicationFiled: May 29, 2014Publication date: September 18, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: Nima Mokhlesi, Mohan V. Dunga, Man Mui
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Patent number: 8837216Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line.Type: GrantFiled: May 13, 2011Date of Patent: September 16, 2014Assignee: Sandisk Technologies Inc.Inventors: Nima Mokhlesi, Mohan V. Dunga, Masaaki Higashitani
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Publication number: 20140254269Abstract: A non-volatile storage system is disclosed that includes pairs (or another number) of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. By sharing bit lines, less bit lines are needed in the storage system. Using less bit lines reduces the space needed to implement the storage system. Each NAND string will have two drain side select gates. The non-volatile storage system will have two drain side selection lines each connected to one of the two drain side select gates so that the NAND strings sharing a bit line can be individually selected. To allow proper selection of a NAND string using the select gates, the select gates will be subjected to non-volatile programming in order to set the threshold voltage of the select gates to an appropriate level.Type: ApplicationFiled: March 11, 2013Publication date: September 11, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Publication number: 20140254268Abstract: A non-volatile storage system includes a plurality of groups of connected non-volatile storage elements. Each group comprises multiple connected data non-volatile storage elements and multiple select gates on a common side of the data non-volatile storage elements. The multiple select gates comprise a first select gate and a second select gate. The first select gate has a first threshold voltage for a first subset of the groups and a second threshold voltage for a second subset of the groups due to active area implantation for the second subset of groups that causes the second threshold voltage to be lower than the first threshold voltage. The second select gate of each group has a programmable threshold voltage. Each of the plurality of bit lines are connected to multiple groups of connected non-volatile storage elements.Type: ApplicationFiled: March 7, 2013Publication date: September 11, 2014Applicant: SANDISK TECHNOLOGIES INC.Inventors: Mohan V. Dunga, Masaaki Higashitani
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Publication number: 20120147676Abstract: A non-volatile storage system is disclosed that includes pairs of NAND strings (or other groupings of memory cells) in the same block being connected to and sharing a common bit line. To operate the system, two selection lines are used so that the NAND strings (or other groupings of memory cells) sharing a bit line can be selected at the block level. Both selection lines are connected to a selection gate for each of the NAND strings (or other groupings of memory cells) sharing the bit line.Type: ApplicationFiled: May 13, 2011Publication date: June 14, 2012Inventors: Nima Mokhlesi, Mohan V. Dunga, Masaaki Higashitani
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Patent number: 7755946Abstract: Temperature effects in a non-volatile storage device are addressed by providing a data state-dependent, and optionally temperature dependent, sense current during verify and read operations. A different sense current is provided for each data state, so that a common temperature coefficient is realized for storage elements with different data states. The temperature coefficient for higher states can be reduced to that of lower states. During sensing, a sense time can be adjusted to achieve a desired sense current when a selected storage element is in a conductive state. A fixed voltage trip point may be maintained. During the sense time, a pre-charged capacitor discharges into a selected storage element such as via a bit line and NAND string, when the selected storage element is in a conductive state. The discharge level is translated to a current which is compared to a state-dependent, and optionally temperature dependent, reference current.Type: GrantFiled: September 19, 2008Date of Patent: July 13, 2010Assignee: Sandisk CorporationInventors: Mohan V. Dunga, Masaaki Higashitani
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Publication number: 20100074014Abstract: Temperature effects in a non-volatile storage device are addressed by providing a data state-dependent, and optionally temperature dependent, sense current during verify and read operations. A different sense current is provided for each data state, so that a common temperature coefficient is realized for storage elements with different data states. The temperature coefficient for higher states can be reduced to that of lower states. During sensing, a sense time can be adjusted to achieve a desired sense current when a selected storage element is in a conductive state. A fixed voltage trip point may be maintained. During the sense time, a pre-charged capacitor discharges into a selected storage element such as via a bit line and NAND string, when the selected storage element is in a conductive state. The discharge level is translated to a current which is compared to a state-dependent, and optionally temperature dependent, reference current.Type: ApplicationFiled: September 19, 2008Publication date: March 25, 2010Inventors: Mohan V. Dunga, Masaaki Higashitani