Patents by Inventor Masaaki Kubotera

Masaaki Kubotera 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: 5088065
    Abstract: Information read out from a memory cell of a static type semiconductor memory is subjected to multi-stage sense amplification in an initial stage sense amplifier, a post-stage sense amplifier and a main amplifier and then transmitted to the input of an output buffer circuit. Since an equalizing circuit is connected to the complementary inputs of each stage of the multi-stage sense amplifier, an inverse information read operation can be executed at high speed. Initially, the initial stage sense amplifier, the post-stage sense amplifier and the main amplifier are controlled to operate in high amplification gain conditions so as to execute high speed sense amplification and thereafter controlled to operate in such low power consumption conditions that the read-out information output obtained by the high speed sense amplification will not disappear.
    Type: Grant
    Filed: October 5, 1990
    Date of Patent: February 11, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Shoji Hanamura, Masaaki Kubotera, Katsuro Sasaki, Takao Oono, Kiyotsugu Ueda
  • Patent number: 4891792
    Abstract: Information read out from a memory cell of a static type semiconductor memory is subjected to multi-stage sense amplification in an initial stage sense amplifier, a post-stage snese amplifier and a main amplifier and then transmitted to the input of an output buffer circuit. Since an equalizing circuit is connected to the complementary inputs of each stage of the multi-stage sense amplifier, an inverse information read operation can be executed at high speed. Initially, the initial stage sense amplifier, the post-stage sense amplifier and the main amplifier are controlled to operate in high amplification gain conditions so as to execute high speed sense amplification and thereafter controlled to operate in such low power consumption conditions that the read-out information output obtained by the high speed sense amplification will not disappear.
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: January 2, 1990
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Shoji Hanamura, Masaaki Kubotera, Katsuro Sasaki, Takao Oono, Kiyotsugu Ueda
  • Patent number: 4876669
    Abstract: An MOS static type RAM has a memory cell array comprising of a plurality of static type memory cells arranged in matrix, a plurality of data lines connected to the data input-output terminals of the respective memory cells and a plurality of word lines connected to the selection terminals of the respective memory cells. Data line load circuits are disposed between the power terminal of the circuit and the data lines. Each data line load circuit is kept at a relatively high impedance in the data write-in operation, and at a relatively low impedance in the data read-out operation. The use of the data line load circuits comprised of such variable impedance circuits can speed up the operating speed of the RAM and can accomplish lower power consumption.
    Type: Grant
    Filed: June 7, 1988
    Date of Patent: October 24, 1989
    Assignee: Hitachi Microcomputer Hitachi, Ltd. & Engineering, Ltd.
    Inventors: Sho Yamamoto, Osamu Minato, Makoto Saeki, Yasuo Yoshitomi, Hideaki Nakamura, Masaaki Kubotera
  • Patent number: 4760561
    Abstract: An MOS static type RAM has a memory cell array comprising a plurality of static type memory cells arranged in matrix, a plurality of data lines connected to the data input-output terminals of the respective memory cells and a plurality of word lines connected to the selection terminals of the respective memory cells. Data line load circuits are disposed between the power terminal of the circuit and the data lines. Each data line load circuit is kept at a relatively high impedance in the data write-in operation, and at a relatively low impedance in the data read-out operation. The use of the data line load circuits comprised of such variable impedance circuits can speed up the operating speed of the RAM and can accomplish lower power consumption.
    Type: Grant
    Filed: June 3, 1985
    Date of Patent: July 26, 1988
    Assignees: Hitachi, Ltd., Hitachi Microcomputer Eng.
    Inventors: Sho Yamamoto, Osamu Minato, Makoto Saeki, Yasuo Yoshitomi, Hideaki Nakamura, Masaaki Kubotera