Patents by Inventor Shigeki Ohbayashi

Shigeki Ohbayashi 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: 10262707
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: May 4, 2017
    Date of Patent: April 16, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Patent number: 10229721
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: May 4, 2017
    Date of Patent: March 12, 2019
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20170236579
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Application
    Filed: May 4, 2017
    Publication date: August 17, 2017
    Applicant: Renesas Electronics Corporation
    Inventors: Koji NII, Shigeki OHBAYASHI, Yasumasa TSUKAMOTO, Makoto YABUUCHI
  • Patent number: 9672900
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: June 6, 2017
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20160172023
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Application
    Filed: February 24, 2016
    Publication date: June 16, 2016
    Applicant: Renesas Electronics Corporation
    Inventors: Koji NII, Shigeki OHBAYASHI, Yasumasa TSUKAMOTO, Makoto YABUUCHI
  • Patent number: 9299418
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: April 28, 2014
    Date of Patent: March 29, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Patent number: 8908419
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: December 9, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Hidemoto Tomita, Shigeki Ohbayashi, Yoshiyuki Ishigaki
  • Publication number: 20140293680
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Application
    Filed: April 28, 2014
    Publication date: October 2, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Koji NII, Shigeki OHBAYASHI, Yasumasa TSUKAMOTO, Makoto YABUUCHI
  • Patent number: 8743645
    Abstract: In a semiconductor memory device, static memory cells are arranged in rows and columns, word lines correspond to respective memory cell rows, and word line drivers drive correspond to word lines. Cell power supply lines correspond to respective memory cell columns and are coupled to cell power supply nodes of a memory cell in a corresponding column. Down power supply lines are arranged corresponding to respective memory cell columns, maintained at ground voltage in data reading and rendered electrically floating in data writing. Write assist elements are arranged corresponding to the cell power supply lines, and according to a write column instruction signal for stopping supply of a cell power supply voltage to the cell power supply line in a selected column, and for coupling the cell power supply line arranged corresponding to the selected column at least to the down power supply line on the corresponding column.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: June 3, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20130234256
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Application
    Filed: March 18, 2013
    Publication date: September 12, 2013
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Hidemoto TOMITA, Shigeki OHBAYASHI, Yoshiyuki ISHIGAKI
  • Patent number: 8422274
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: April 16, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Hidemoto Tomita, Shigeki Ohbayashi, Yoshiyuki Ishigaki
  • Patent number: 8395932
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: March 12, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Hidemoto Tomita, Shigeki Ohbayashi, Yoshiyuki Ishigaki
  • Publication number: 20120087198
    Abstract: A level shift element adjusting a voltage level at the time of selection of a word line according to fluctuations in threshold voltage of a memory cell transistor is arranged for each word line. This level shift element lowers a driver power supply voltage, and transmits the level-shifted voltage onto a selected word line. The level shift element can be replaced with a pull-down element for pulling down the word line voltage according to the threshold voltage level of the memory cell transistor. In either case, the selected word line voltage level can be adjusted according to the fluctuations in threshold voltage of the memory cell transistor without using another power supply system. Thus, the power supply circuitry is not complicated, and it is possible to achieve a semiconductor memory device that can stably read and write data even with a low power supply voltage.
    Type: Application
    Filed: December 14, 2011
    Publication date: April 12, 2012
    Applicant: Renesas Electronics Corporation
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20120063213
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Application
    Filed: November 15, 2011
    Publication date: March 15, 2012
    Applicant: Renesas Electronics Corporation
    Inventors: Hidemoto Tomita, Shigeki Ohbayashi, Yoshiyuki Ishigaki
  • Patent number: 8098533
    Abstract: A level shift element adjusting a voltage level at the time of selection of a word line according to fluctuations in threshold voltage of a memory cell transistor is arranged for each word line. This level shift element lowers a driver power supply voltage, and transmits the level-shifted voltage onto a selected word line. The level shift element can be replaced with a pull-down element for pulling down the word line voltage according to the threshold voltage level of the memory cell transistor. In either case, the selected word line voltage level can be adjusted according to the fluctuations in threshold voltage of the memory cell transistor without using another power supply system. Thus, the power supply circuitry is not complicated, and it is possible to achieve a semiconductor memory device that can stably read and write data even with a low power supply voltage.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: January 17, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Publication number: 20100265752
    Abstract: A semiconductor storage device includes a memory cell array, a plurality of word lines, a plurality of bit lines, a first gate wiring element 3a, 3b, a second gate wiring element 3c, 3d, a first connector 5a, 5b, and a second connector 5c, 5d. Each memory cell 10 has first and second sets having a driver transistor 11, a load transistor 12, and an access transistor 13. The word lines are arranged in parallel to each other along a first direction. The bit lines are arranged in parallel to each other along a second direction perpendicular to the first direction. The first gate wiring element comprises a gate electrode of the first driver transistor and the first load transistor, and has a rectangular shape having straight line on opposite sides. The second gate wiring element comprises a gate electrode of the access transistor and has a rectangular shape having straight line on opposite sides.
    Type: Application
    Filed: June 30, 2010
    Publication date: October 21, 2010
    Applicant: Renesas Technology Corp.
    Inventors: Hidemoto TOMITA, Shigeki Ohbayashi, Yoshiyuki Ishigaki
  • Publication number: 20090268531
    Abstract: A level shift element adjusting a voltage level at the time of selection of a word line according to fluctuations in threshold voltage of a memory cell transistor is arranged for each word line. This level shift element lowers a driver power supply voltage, and transmits the level-shifted voltage onto a selected word line. The level shift element can be replaced with a pull-down element for pulling down the word line voltage according to the threshold voltage level of the memory cell transistor. In either case, the selected word line voltage level can be adjusted according to the fluctuations in threshold voltage of the memory cell transistor without using another power supply system. Thus, the power supply circuitry is not complicated, and it is possible to achieve a semiconductor memory device that can stably read and write data even with a low power supply voltage.
    Type: Application
    Filed: June 25, 2009
    Publication date: October 29, 2009
    Applicant: Renesas Technology Corp.
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Patent number: 7589566
    Abstract: A CMOS LSI includes an inverter including first and second MOS transistors, a relatively long metal interconnection connected to an input node of the inverter, first and second diodes releasing charges born by the metal interconnection during a plasma process to first and second wells, and first and second MOS transistors maintaining a voltage between the first and second wells at a level not higher than a prescribed voltage. Therefore, even when an antenna ratio is high, a gate oxide film in the first and second MOS transistors is not damaged during the plasma process.
    Type: Grant
    Filed: December 1, 2005
    Date of Patent: September 15, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Shigeki Ohbayashi, Hiroaki Suzuki, Koichiro Ishibashi, Hiroshi Makino
  • Patent number: 7570525
    Abstract: A level shift element adjusting a voltage level at the time of selection of a word line according to fluctuations in threshold voltage of a memory cell transistor is arranged for each word line. This level shift element lowers a driver power supply voltage, and transmits the level-shifted voltage onto a selected word line. The level shift element can be replaced with a pull-down element for pulling down the word line voltage according to the threshold voltage level of the memory cell transistor. In either case, the selected word line voltage level can be adjusted according to the fluctuations in threshold voltage of the memory cell transistor without using another power supply system. Thus, the power supply circuitry is not complicated, and it is possible to achieve a semiconductor memory device that can stably read and write data even with a low power supply voltage.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: August 4, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Koji Nii, Shigeki Ohbayashi, Yasumasa Tsukamoto, Makoto Yabuuchi
  • Patent number: 7505339
    Abstract: A supply instruction signal attains the H-level before data is written into a plurality of memory cells. A P-channel MOS transistor is arranged between a power supply node and an input node. The P-channel MOS transistor is turned off to open the input node according to the supply instruction signal. In this case, a write driver discharges electric charges accumulated on the input node and electric charges accumulated on a bit line pair. However, a through-current does not flow from the power supply node to a ground node so that flow of the through-current to a CMOS inverter circuit forming each memory cell can be prevented. Accordingly, such a static semiconductor memory device can be provided that can prevent the flow of the through-current to the CMOS inverter circuit forming each memory cell when simultaneously writing data into the plurality of memory cells.
    Type: Grant
    Filed: June 13, 2006
    Date of Patent: March 17, 2009
    Assignee: Renesas Technology Corp.
    Inventor: Shigeki Ohbayashi