Patents by Inventor Yasue Yamamoto

Yasue Yamamoto 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).

  • Patent number: 11978516
    Abstract: A memory system having a dynamic supply voltage to sense amplifiers. The supply voltage has a higher magnitude when charging inhibited bit lines during a program operation and a lower magnitude when verifying/sensing memory cells. Reducing the magnitude of the supply voltage saves power and/or current. However, if the lower magnitude were used when the inhibited bit lines are charged during the program operations, some of the memory cells that should be inhibited from programming might experience at least some programming. Using the higher magnitude supply voltage during bit line charging of the program operation assures that the inhibited bit lines are charged to a sufficient voltage to keep drain side select gates of NAND strings off so that the NAND channel will boost properly to inhibit programming of such memory cells.
    Type: Grant
    Filed: April 11, 2022
    Date of Patent: May 7, 2024
    Assignee: SanDisk Technologies LLC
    Inventors: Yanjie Wang, Ohwon Kwon, Kou Tei, Tai-Yuan Tseng, Yasue Yamamoto, Yonggang Wu, Guirong Liang
  • Publication number: 20230326531
    Abstract: Technology is disclosed herein for a memory system having a dynamic supply voltage to sense amplifiers. In an aspect, the supply voltage has a higher magnitude when charging inhibited bit lines during a program operation and a lower magnitude when verifying/sensing memory cells. Reducing the magnitude of the supply voltage saves power and/or current. However, if the lower magnitude were used when the inhibited bit lines are charged during the program operations, some of the memory cells that should be inhibited from programming might experience at least some programming. Using the higher magnitude supply voltage during bit line charging of the program operation assures that the inhibited bit lines are charged to a sufficient voltage to keep drain side select gates of NAND strings off so that the NAND channel will boost properly to inhibit programming of such memory cells.
    Type: Application
    Filed: April 11, 2022
    Publication date: October 12, 2023
    Applicant: SanDisk Technologies LLC
    Inventors: Yanjie Wang, Ohwon Kwon, Kou Tei, Tai-Yuan Tseng, Yasue Yamamoto, Yonggang Wu, Guirong Liang
  • Patent number: 9373389
    Abstract: A semiconductor memory device having a memory cell array in which a plurality of memory cells are arranged in columns and rows to form a matrix pattern includes read word lines, read bit lines, and read source lines. Each of the plurality of memory cells includes: first and second inverters which are cross-coupled to each other; a first transistor which is connected between a read bit line and a read source line and of which the gate is connected to the output terminal of the first inverter; and a second transistor which is connected in series to the first transistor and of which the gate is connected to a read word line.
    Type: Grant
    Filed: January 6, 2016
    Date of Patent: June 21, 2016
    Assignee: SOCIONEXT INC.
    Inventor: Yasue Yamamoto
  • Publication number: 20160118108
    Abstract: A semiconductor memory device having a memory cell array in which a plurality of memory cells are arranged in columns and rows to form a matrix pattern includes read word lines, read bit lines, and read source lines. Each of the plurality of memory cells includes: first and second inverters which are cross-coupled to each other; a first transistor which is connected between a read bit line and a read source line and of which the gate is connected to the output terminal of the first inverter; and a second transistor which is connected in series to the first transistor and of which the gate is connected to a read word line.
    Type: Application
    Filed: January 6, 2016
    Publication date: April 28, 2016
    Inventor: Yasue Yamamoto
  • Patent number: 8094498
    Abstract: In a nonvolatile semiconductor memory device storing data by accumulating charges in a floating gate, memory units, each of which includes a first MOS transistor as a read device, a bit cell composed of a first capacitor as a capacitance coupling device and a second capacitor as an erase device, and a decode device including a second MOS transistor and a third MOS transistor, are arranged in array. This attains nonvolatile memory capable of bit by bit selective erase arranged in array to thus reduce the core area remarkably.
    Type: Grant
    Filed: June 2, 2010
    Date of Patent: January 10, 2012
    Assignee: Panasonic Corporation
    Inventors: Yasue Yamamoto, Masanori Shirahama, Yasuhiro Agata, Toshiaki Kawasaki
  • Patent number: 7884642
    Abstract: A system LSI includes an input/output section and a logic circuit section. The input/output section includes an I/O power source cell having a supply voltage higher than a power source for the logic circuit section and a plurality of I/O cells in each of which an I/O power source line is provided for supplying source power from the I/O power source cell. The logic circuit section includes an I/O power consuming circuit which uses the I/O power source cell as a power source. The I/O power consuming circuit is connected to a line leading from an I/O power source line in at least one of the plurality of I/O cells.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: February 8, 2011
    Assignee: Panasonic Corporation
    Inventors: Yasuhiro Agata, Toshiaki Kawasaki, Masanori Shirahama, Ryuji Nishihara, Shinichi Sumi, Yasue Yamamoto, Hirohito Kikukawa
  • Publication number: 20100238735
    Abstract: In a nonvolatile semiconductor memory device storing data by accumulating charges in a floating gate, memory units, each of which includes a first MOS transistor as a read device, a bit cell composed of a first capacitor as a capacitance coupling device and a second capacitor as an erase device, and a decode device including a second MOS transistor and a third MOS transistor, are arranged in array. This attains nonvolatile memory capable of bit by bit selective erase arranged in array to thus reduce the core area remarkably.
    Type: Application
    Filed: June 2, 2010
    Publication date: September 23, 2010
    Applicant: Panasonic Corporation
    Inventors: Yasue YAMAMOTO, Masanori SHIRAHAMA, Yasuhiro AGATA, Toshiaki KAWASAKI
  • Patent number: 7764108
    Abstract: A gate of a MOS transistor connected to a fuse device in series is controlled by an AND circuit connected to the same power source as the fuse device is connected, thereby pulling down one input of the AND circuit to a ground. Thus, misprogramming of the fuse device when an LSI power source is turned ON/OFF can be prevented.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: July 27, 2010
    Assignee: Panasonic Corporation
    Inventors: Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki, Shinichi Sumi, Yasue Yamamoto
  • Patent number: 7755941
    Abstract: In a nonvolatile semiconductor memory device storing data by accumulating charges in a floating gate, memory units, each of which includes a first MOS transistor as a read device, a bit cell composed of a first capacitor as a capacitance coupling device and a second capacitor as an erase device, and a decode device including a second MOS transistor and a third MOS transistor, are arranged in array. This attains nonvolatile memory capable of bit by bit selective erase arranged in array to thus reduce the core area remarkably.
    Type: Grant
    Filed: January 9, 2008
    Date of Patent: July 13, 2010
    Assignee: Panasonic Corporation
    Inventors: Yasue Yamamoto, Masanori Shirahama, Yasuhiro Agata, Toshiaki Kawasaki
  • Publication number: 20100164542
    Abstract: A system LSI includes an input/output section and a logic circuit section. The input/output section includes an I/O power source cell having a supply voltage higher than a power source for the logic circuit section and a plurality of I/O cells in each of which an I/O power source line is provided for supplying source power from the I/O power source cell. The logic circuit section includes an I/O power consuming circuit which uses the I/O power source cell as a power source. The I/O power consuming circuit is connected to a line leading from an I/O power source line in at least one of the plurality of I/O cells.
    Type: Application
    Filed: March 11, 2010
    Publication date: July 1, 2010
    Applicant: Panasonic Corporation
    Inventors: Yasuhiro AGATA, Toshiaki Kawasaki, Masanori Shirahama, Ryuji Nishihara, Shinichi Sumi, Yasue Yamamoto, Hirohito Kikukawa
  • Patent number: 7696779
    Abstract: A system LSI includes an input/output section and a logic circuit section. The input/output section includes an I/O power source cell having a supply voltage higher than a power source for the logic circuit section and a plurality of I/O cells in each of which an I/O power source line is provided for supplying source power from the I/O power source cell. The logic circuit section includes an I/O power consuming circuit which uses the I/O power source cell as a power source. The I/O power consuming circuit is connected to a line leading from an I/O power source line in at least one of the plurality of I/O cells.
    Type: Grant
    Filed: September 26, 2006
    Date of Patent: April 13, 2010
    Assignee: Panasonic Corporation
    Inventors: Yasuhiro Agata, Toshiaki Kawasaki, Masanori Shirahama, Ryuji Nishihara, Shinichi Sumi, Yasue Yamamoto, Hirohito Kikukawa
  • Patent number: 7623380
    Abstract: A nonvolatile semiconductor memory device for storing data by accumulating charge in a floating gate includes a plurality of MOS transistors sharing the floating gate. In the device, a PMOS is used for coupling during writing and an n-type depletion MOS (DMOS) is used for coupling during erasure. Coupling of channel inversion capacitance by the PMOS is used for writing and coupling of depletion capacitance by the n-type DMOS is used for erasure, thereby increasing the erase speed without increase of area, as compared to a conventional three-transistor nonvolatile memory element.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: November 24, 2009
    Assignee: Panasonic Corporation
    Inventors: Yasue Yamamoto, Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki
  • Patent number: 7602231
    Abstract: A circuit includes a plurality of stages each including a MOS transistor and a capacitor of which one end is connected to one of a drain and a source of the MOS transistor. The plurality of stages are connected with each other by cascade connection of the MOS transistors. A gate of the MOS transistor is connected electrically to one of the drain and the source thereof in each stage, and a substrate for at least one pair of adjacent MOS transistors are connected electrically to one of the drain and the source of one of the pair. The back bias effect is suppressed, and the layout area is reduced. Further, a plurality of booster capacitors connected in series are provided in succeeding stages, thereby suppressing degradation of breakdown voltage of each capacitor.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: October 13, 2009
    Assignee: Panasonic Corporation
    Inventors: Yasue Yamamoto, Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki
  • Publication number: 20090189226
    Abstract: An electrical fuse circuit includes, in addition to an independent power supply switch circuit, a plurality of fuse bit cells, each including a fuse element one end of which is connected to an output of the power supply switch circuit, and a first MOS transistor connected to the other end of the fuse element, wherein a diode is connected between the ground potential and the power supply switch circuit as an ESD countermeasure. The gate oxide film thickness of transistors of the fuse bit cells is equal to that of a low-voltage logic-type transistor, not that of a high-voltage I/O-type transistor.
    Type: Application
    Filed: October 8, 2008
    Publication date: July 30, 2009
    Inventors: Yasue YAMAMOTO, Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki
  • Patent number: 7535748
    Abstract: A memory cell is constructed by connecting in series a variable-resistance element having a resistance which is varied by application of a positive voltage to one terminal (first node) thereof using a potential at the other terminal thereof as a reference and a diode which allows a current to flow therethrough by application of a positive voltage to the other terminal thereof using a potential at one terminal (second node) thereof as a reference. The first node is connected to the corresponding column select line and the second node is connected to the corresponding row select line. Then, to a non-selected row select line, a potential higher than when the row select line is selected is applied by using a row control circuit. By using column-select-line driver circuits, predetermined potentials corresponding to a non-selection period, a data write period, a reset period, and a data read period are applied to the column select line.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: May 19, 2009
    Assignee: Panasonic Corporation
    Inventors: Masanori Shirahama, Yasuhiro Agata, Yasue Yamamoto
  • Patent number: 7518903
    Abstract: In a semiconductor memory device including resistance change memory devices, when a resistance change memory device is in standby mode, the two terminals of the resistance change memory device, i.e., a bit line and a source line, are set at a precharge potential Vp, respectively. At the time of a set operation, the bit line is set to a set voltage Vd, which is higher than the precharge potential Vp, while the source line is grounded. At the time of a reset operation, bit line is grounded, while the source line is set to the set voltage Vd. At the time of a data-read operation, the source line is grounded by a read bias generation circuit, while the potential of the bit line is kept at the precharge potential Vp.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: April 14, 2009
    Assignee: Panasonic Corporation
    Inventors: Masanori Shirahama, Yasuhiro Agata, Yasue Yamamoto, Hirohito Kikukawa
  • Publication number: 20080205144
    Abstract: In a nonvolatile semiconductor memory device storing data by accumulating charges in a floating gate, memory units, each of which includes a first MOS transistor as a read device, a bit cell composed of a first capacitor as a capacitance coupling device and a second capacitor as an erase device, and a decode device including a second MOS transistor and a third MOS transistor, are arranged in array. This attains nonvolatile memory capable of bit by bit selective erase arranged in array to thus reduce the core area remarkably.
    Type: Application
    Filed: January 9, 2008
    Publication date: August 28, 2008
    Inventors: Yasue YAMAMOTO, Masanori SHIRAHAMA, Yasuhiro AGATA, Toshiaki KAWASAKI
  • Patent number: 7397720
    Abstract: Electrical fuse blocks (100) of a plurality of stages are provided each of which includes a plurality of electrical fuse cores (101). The electrical fuse block (100) includes a program shift register block (103) made up of shift registers (107) which are disposed for the respective electrical fuse cores (101), sequentially transmit program enable signal FPGI, and output the program enable signal FPGI to the NMOS transistors (105) of the electrical fuse cores (101). When performing programming according to programming decision signal PBn, the program shift register block (103) transmits the program enable signal FPGI. When not performing programming, the program shift register block (103) skips the program enable signal FPGI.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: July 8, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichi Sumi, Hirohito Kikukawa, Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki, Ryuji Nishihara, Yasue Yamamoto
  • Publication number: 20080150613
    Abstract: A gate of a MOS transistor connected to a fuse device in series is controlled by an AND circuit connected to the same power source as the fuse device is connected, thereby pulling down one input of the AND circuit to a ground. Thus, misprogramming of the fuse device when an LSI power source is turned ON/OFF can be prevented.
    Type: Application
    Filed: October 26, 2007
    Publication date: June 26, 2008
    Inventors: Yasuhiro Agata, Masanori Shirahama, Toshiaki Kawasaki, Shinichi Sumi, Yasue Yamamoto
  • Publication number: 20080112210
    Abstract: A memory cell is constructed by connecting in series a variable-resistance element having a resistance which is varied by application of a positive voltage to one terminal (first node) thereof using a potential at the other terminal thereof as a reference and a diode which allows a current to flow therethrough by application of a positive voltage to the other terminal thereof using a potential at one terminal (second node) thereof as a reference. The first node is connected to the corresponding column select line and the second node is connected to the corresponding row select line. Then, to a non-selected row select line, a potential higher than when the row select line is selected is applied by using a row control circuit. By using column-select-line driver circuits, predetermined potentials corresponding to a non-selection period, a data write period, a reset period, and a data read period are applied to the column select line.
    Type: Application
    Filed: October 2, 2007
    Publication date: May 15, 2008
    Inventors: Masanori SHIRAHAMA, Yasuhiro AGATA, Yasue YAMAMOTO