Patents by Inventor Hirofumi Zushi

Hirofumi Zushi 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).

  • Publication number: 20060145266
    Abstract: A semiconductor integrated circuit, whose MOS transistors' layout structure is determined in consideration of the size of a device active region in a gate length direction, in which each transistor is formed. When stresses coming from the device isolation region, etc. are taken into account, for a circuit whose current driving power reduction caused by the stresses should be suppressed, the distance between the device isolation regions in the gate length direction may be selected so as to suppress the reduction in drain-source current. Further, for a circuit whose logical threshold voltage variations caused by the stresses should be suppressed, the distance between the device isolation regions in the gate length direction may be selected so that the variations in drain-source current caused by such stresses are balanced between the p-channel and n-channel transistors. Characteristic variations arising in the transistors owing to stresses coming from the device isolation region, etc.
    Type: Application
    Filed: January 3, 2006
    Publication date: July 6, 2006
    Inventors: Hirofumi Zushi, Kinya Mitsumoto
  • Patent number: 6271687
    Abstract: A sense amplifier, which is intended to reduce the output response time after it has received a small voltage difference until it delivers amplified output signals, consists of a latch circuit made up of a pair of CMOS inverters, a pair of NMOS transistors connected in parallel to the latch circuit, and a current source connected in series to the latch circuit and NMOS transistor pair. The NMOS transistors amplify a small voltage difference of input signals, and the inverters of the latch circuit further amplify the resulting voltage difference to produce the output signals. Based on a small voltage difference of input signals being amplified in two stages and the amplifying circuit being 2-stage serial connection of the current source and the NMOS transistor or CMOS inverter, the delay time of output response can be reduced.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: August 7, 2001
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Hiroshi Toyoshima, Masashige Harada, Tomohiro Nagano, Yoji Nishio, Atsushi Hiraishi, Kunihiro Komiyaji, Hideharu Yahata, Kenichi Fukui, Hirofumi Zushi, Takahiro Sonoda, Haruko Kawachino, Sadayuki Morita
  • Patent number: 6046609
    Abstract: A sense amplifier, which is intended to reduce the output response time after it has received a small voltage difference until it delivers amplified output signals, consists of a latch circuit made up of a pair of CMOS inverters, a pair of NMOS transistors connected in parallel to the latch circuit, and a current source connected in series to the latch circuit and NMOS transistor pair. The NMOS transistors amplify a small voltage difference of input signals, and the inverters of the latch circuit further amplify the resulting voltage difference to produce the output signals. Based on is a small voltage difference of input signals being amplified in two stages and the amplifying circuit being a 2-stage serial connection of the current source and the NMOS transistor or CMOS inverter, the delay time of output response can be reduced.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: April 4, 2000
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Hiroshi Toyoshima, Masashige Harada, Tomohiro Nagano, Yoji Nishio, Atsushi Hiraishi, Kunihiro Komiyaji, Hideharu Yahata, Kenichi Fukui, Hirofumi Zushi, Takahiro Sonoda, Haruko Kawachino, Sadayuki Morita
  • Patent number: 5936909
    Abstract: A static RAM has plurality of memory mats each including a plurality of static memory cells formed in a matrix pattern at points of intersection between a plurality of word lines and a plurality of data lines. upon receipt of an address signal into an address register, an address selection circuit selects a memory cell in one of the memory mats, and connects the selected memory cell to a sense amplifier or a write amplifier furnished corresponding to the memory mat in question. At the same time, an address counter generates an address signal corresponding to the address signal by which one of the memory mats has been selected. When a burst mode is designated by a control signal, the address signal admitted to the address register is used to select a memory cell in a first memory mat. The selected memory cell is connected to the corresponding sense amplifier or write amplifier.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: August 10, 1999
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Takahiro Sonoda, Sadayuki Morita, Hirofumi Zushi, Haruko Kawachino, Hideharu Yahata, Kenichi Fukui, Tomohiro Nagano, Masashige Harada
  • Patent number: 5854562
    Abstract: A sense amplifier, which is intended to reduce the output response time after it has received a small voltage difference until it delivers amplified output signals, consists of a latch circuit made up of a pair of CMOS inverters, a pair of NMOS transistors connected in parallel to the latch circuit, and a current source connected in series to the latch circuit and NMOS transistor pair. The NMOS transistors amplify a small voltage difference of input signals, and the inverters of the latch circuit further amplify the resulting voltage difference to produce the output signals. Based on is a small voltage difference of input signals being amplified in two stages and the amplifying circuit being of 2-stage serial connection of the current source and the NMOS transistor or CMOS inverter, the delay time of output response can be reduced.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: December 29, 1998
    Assignees: Hitachi, Ltd, Hitachi ULSI Engineering Corp.
    Inventors: Hiroshi Toyoshima, Masashige Harada, Tomohiro Nagano, Yoji Nishio, Atsushi Hiraishi, Kunihiro Komiyaji, Hideharu Yahata, Kenichi Fukui, Hirofumi Zushi, Takahiro Sonoda, Haruko Kawachino, Sadayuki Morita
  • Patent number: D836186
    Type: Grant
    Filed: January 4, 2017
    Date of Patent: December 18, 2018
    Assignee: Valqua, Ltd.
    Inventors: Kenichi Takahashi, Akira Ueda, Hirofumi Zushi, Sayaka Yoshida
  • Patent number: D865920
    Type: Grant
    Filed: March 6, 2018
    Date of Patent: November 5, 2019
    Assignee: Valqua, Ltd.
    Inventors: Kenichi Takahashi, Akira Ueda, Hirofumi Zushi, Sayaka Yoshida