Patents by Inventor Katsushi Nagaba

Katsushi Nagaba 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: 20020036301
    Abstract: A semiconductor integrated circuit device comprises a register circuit receives a data signal, a delay adjustment circuit receives an output of the register circuit and a driver circuit receives an output of the delay adjustment circuit. An output timing of the register circuit is controlled by a clock signal. A delay time of the delay adjustment circuit is adjusted by a delay adjustment signal based on the data signal.
    Type: Application
    Filed: September 25, 2001
    Publication date: March 28, 2002
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Katsushi Nagaba, Shigeo Ohshima
  • Patent number: 6226204
    Abstract: The data output circuit in a clock synchronous DRAM comprises a first data transfer circuit to which the data read from a memory is input and which transfers the input data to the output side in synchronization with an internal clock, an equalizing circuit to which the output of the first data transfer circuit is input during a read operation by a burst operation and to which high-impedance data is input after the read operation, a second data transfer circuit connected to the equalizing circuit, and an output buffer to which the output of the second data transfer circuit is input. The second data transfer circuit transfers all the data to the output buffer in synchronization with an output clock. This eliminates the dependence of the data access time and data hold time on data item and/or cycle and facilitates the timing control of the output control signal.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: May 1, 2001
    Assignee: Kabushuki Kaisha Toshiba
    Inventors: Kazuko Inuzuka, Katsushi Nagaba, Shigeo Ohshima
  • Patent number: 5841730
    Abstract: A semiconductor memory device capable of shortening data reading time in a first read cycle after the mode has been changed from a write mode to a read mode while maintaining high-speed cycle time when data is written despite simple structure, the semiconductor memory device having a memory cell array having a plurality of dynamic memory cells, to which data can be written, data line pairs to which data read from the memory cells and data which must be written on the memory cells are transferred, a write driver for driving the data line pairs in accordance with write data supplied from outside when data is written to the memory cells and an equalizing circuit for setting the data line pairs to an intermediate potential whenever the data line pairs are operated by the write driver.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: November 24, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuyuki Kai, Katsushi Nagaba, Shigeo Ohshima
  • Patent number: 5777946
    Abstract: The present invention provides a semiconductor memory circuit capable of high-speed access to a predetermined column portion by a simplified high-speed addressing circuit. The memory circuit in a DRAM is such that a portion of a column addressing circuit normally comprising a counter constitutes a shift register in a column addressing circuit at a preceding stage of a column address buffer so that a plurality of address signal wrappings are realized for accessing the predetermined column portion.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: July 7, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuko Inuzuka, Shigeo Ohshima, Katsushi Nagaba
  • Patent number: 5724281
    Abstract: The input pads DQ0 to DQ3 and the input buffers DIB0 to DIB3 are connected to each other by means of the wires La or Lb. In the case where the memory cell array is of the .times.4 bit pattern, the input pads DQ0 to DQ3 are connected to the input terminals of the input buffers DIB0 to DIB3, respectively, via the wires La, whereas in the case where the memory cell array is of the .times.1 bit pattern, one of the input pads, that is, DQ0 is connected to each of the input terminals of the input buffers DIB0 to DIB3 via the wires Lb. The structures from the input buffers DIB0 to DIB3 to the memory cell arrays are the same and common to the .times.4 bit pattern and the .times.1 bit pattern, and therefore an increase in the driving performance of the transistors in the input buffers DIB0 to DIB3 can be suppressed.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: March 3, 1998
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Katsushi Nagaba
  • Patent number: 5274592
    Abstract: A semiconductor integrated circuit device having a high-efficiency transfer gate and which is applicable to a DRAM which has voltage-raised word lines configured from a data retention node, a data line that is precharged to a required level, a MOS transistor with the source and the drain each connected to a data line and a data retention node, a sense amplifier that amplifies the data that has been transferred to the data line via this MOS transistor a step-up circuit that applies a voltage that is higher than the drain voltage when compared with an absolute value, to the gate of the MOS transistor, and a step-down circuit for reducing the absolute value of a gate voltage of the MOS transistor at the timing of activation of the sense amplifier.
    Type: Grant
    Filed: December 13, 1991
    Date of Patent: December 28, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsushi Sueoka, Katsushi Nagaba, Hiroyuki Koinuma
  • Patent number: 4907200
    Abstract: A dynamic memory having pairs of bit lines. A sense amplifier is connected between each pair of bit lines for detecting data from the potential difference between these bit lines. The memory further comprises first and second pair of dummy word lines. A capacitor is coupled between the first of each pair of bit lines, on the one hand, and the first pair of dummy word lines, on the other. Similarly, a capacitor is coupled between the second of each pair of bit lines, on the one hand, and the second pair of dummy word lines, on the other. A first dummy word line driver is connected to the first pair of dummy word lines, for generating a reference potential in the first of each pair of bit lines. A second dummy word line driver is connected to the second pair of dummy word lines, for generating a reference potential in the second of each pair of bit lines. The memory also has a selection circuit for selecting either the first or second dummy word line driver.
    Type: Grant
    Filed: October 27, 1988
    Date of Patent: March 6, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuo Ikawa, Katsushi Nagaba
  • Patent number: 4860327
    Abstract: A first circuit is made up of a first clocked inverter and a first modified clocked inverter. A second circuit is made up of a second clocked inverter and a second modified clocked inverter. The first circuit has substantially the same circuit arrangement as that of the second circuit. The first circuit operates in response of the output signal from the second circuit, and vice versa.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: August 22, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaoru Nakagawa, Katsushi Nagaba