Patents by Inventor Osamu Nagashima

Osamu Nagashima 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: 6222792
    Abstract: A phase control circuit comprises a plurality of fixed delay circuits (200-0 through 200-5) which assign different predetermined delay times to a first clock signal (BDA1) respectively, a detection circuit (201) which receives clock signals outputted from the plurality of fixed delay circuits and a second clock signal (PCLK) different in phase from the first clock signal therein and generates detected signals (202) represented in a plurality of bits each corresponding to the difference in phase between the first clock signal and the second clock signal, and a variable delay circuit (200-6) which gives a delay in the phase difference corresponding to each of the detected signals to a third clock signal (BDA2).
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: April 24, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Hanzawa, Takeshi Sakata, Osamu Nagashima
  • Publication number: 20010000133
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Application
    Filed: December 5, 2000
    Publication date: April 5, 2001
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 6212110
    Abstract: Switch MOSFETS are interposed between a sense amplifier disposed in a dynamic RAM and complementary bit lines. After signal voltages were read out by the selecting operations of the word lines from a plurality of dynamic memory cells selected, to the plurality of pairs of complementary bit lines in accordance with their individual storage informations, the switch control signal of the switch MOSFETs is changed from a select level to a predetermined intermediate level. The switch MOSFETs, supplied with the intermediate potential at their gates, are turned ON as a result that sense nodes are set to one level in accordance with the amplifying operations of the sense amplifier.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: April 3, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuya Sakamoto, Osamu Nagashima, Riichiro Takemura
  • Patent number: 6205086
    Abstract: A phase control circuit comprises a plurality of fixed delay circuits (200-0 through 200-5) which assign different predetermined delay times to a first clock signal (BDA1) respectively, a detection circuit (201) which receives clock signals outputted from the plurality of fixed delay circuits and a second clock signal (PCLK) different in phase from the first clock signal therein and generates detected signals (202) represented in a plurality of bits each corresponding to the difference in phase between the first clock signal and the second clock signal, and a variable delay circuit (200-6) which gives a delay in the phase difference corresponding to each of the detected signals to a third clock signal (BDA2).
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: March 20, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Hanzawa, Takeshi Sakata, Osamu Nagashima
  • Patent number: 6201728
    Abstract: There is produced a first internal voltage having a difference relative to a power supply voltage, the difference being substantially equal to a threshold voltage of an address selection MOSFET of a dynamic memory cell. The first voltage is supplied to a sense amplifier as an operating voltage on a high-level side thereof. There is produced a second internal voltage having a predetermined difference relative to a circuit ground potential. The second voltage is supplied to the sense amplifier as an operating voltage on a low-level side thereof. A write signal having a high level corresponding to the first internal voltage and a low level corresponding to the second internal voltage is generated by a write amplifier to be transferred to a pair of complementary data lines connected to the dynamic memory cell. A high level, e.g., the power supply voltage representing a selection level and a low level, e.g.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: March 13, 2001
    Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp.
    Inventors: Seiji Narui, Osamu Nagashima, Masatoshi Hasegawa, Hiroki Fujisawa, Shinichi Miyatake, Tsuyuki Suzuki, Yasunobu Aoki, Tsutom Takahashi, Kazuhiko Kajigaya
  • Patent number: 5926430
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon reaching its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: July 20, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 5726930
    Abstract: A semiconductor memory device capable of simultaneously providing volatile and non-volatile portions is disclosed having a plurality of memory mats, and a plurality of plate electrodes and a plurality of memory mats each provided in one-to-one correspondence with the memory maps. The memory mats each include a plurality of word lines, a plurality of bit lines and a plurality of memory cells provided at the intersections of the word lines and the bit lines. The memory cells each include an information storage capacitor having a ferroelectric film, and an address selection MOSFET. The information storage capacitor has a pair of electrodes, one of which is connected to the plate electrode that corresponds to the memory mat in which the information storage capacitor is included. A first voltage or a second voltage is selectively applied to each of the plate electrodes according to data held in the memory circuit corresponding to the plate electrode.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: March 10, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Masatoshi Hasegawa, Kazuhiko Kajigaya, Kan Takeuchi, Katsumi Matsuno, Osamu Nagashima
  • Patent number: 5724297
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: December 12, 1996
    Date of Patent: March 3, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Patent number: 5615145
    Abstract: A semiconductor memory which includes a plurality of memory cells each having first and second capacitors connected in series and a field-effect transistor whose source or drain is connected to a node between the first and second capacitors. The memory cells are arranged at intersections of bit lines and word lines thereby forming a matrix. The first capacitor of each memory cell is a ferroelectric capacitor using a ferroelectric material as an insulating film. A plate electrode of the first capacitor of each memory cell is held at a first potential when the memory is operated in a first mode and the plate electrode of the first capacitor is held at a second potential when the memory is operated in a second mode. The first potential is different from the second potential.
    Type: Grant
    Filed: December 20, 1995
    Date of Patent: March 25, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Kan Takeuchi, Katsumi Matsuno, Kazuhiko Kajiyama, Osamu Nagashima, Masatoshi Hasegawa
  • Patent number: 4947373
    Abstract: A semiconductor memory is provided with a first memory cell group, a second memory cell group, a first register for a serial output operation for holding information related to the first memory cell group, a second register for a serial output operation for holding information related to the second memory cell group, and transfer means for transferring information related to either the first or second memory cell group to either the first or second serial output register. By virtue of this arrangement, while the information transferred to the first serial output register is being serially output therefrom, information can simultaneously be transferred to the second serial output register by the transfer means.
    Type: Grant
    Filed: December 17, 1987
    Date of Patent: August 7, 1990
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Yasunori Yamaguchi, Katsuyuki Sato, Jun Mitake, Hitoshi Kawaguchi, Masahiro Yoshida, Terutaka Okada, Makoto Morino, Tetsuya Saeki, Yosuke Yukawa, Osamu Nagashima