Patents by Inventor Toshimasa Namekawa

Toshimasa Namekawa 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: 20230154532
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of memory cells each including a resistance change type memory element configured to store a resistance state and a switch, a read determination circuit that compares a measurement signal from the memory cell selected in the memory cell array with a reference signal to determine a resistance state so as to read information from the resistance change type memory element, and a reference signal correction unit that corrects a level of the reference signal based on a selected position of the memory cell in the memory cell array.
    Type: Application
    Filed: November 17, 2022
    Publication date: May 18, 2023
    Inventors: Hiroshi YOSHIDA, Toshimasa NAMEKAWA, Satoru ARAKI, Etsuo FUKUDA, Tetsuo ENDOH
  • Publication number: 20230155501
    Abstract: According to one embodiment, a switching power circuit compares a reference voltage with a feedback voltage of an output voltage, and controls the output voltage in accordance with the reference voltage, in which in a case where the output current is greater than a predetermined set current, the voltage of the reference voltage is decreased.
    Type: Application
    Filed: January 19, 2023
    Publication date: May 18, 2023
    Inventors: Toshimasa Namekawa, Ryoma Matsuo, Katsumasa Tanaka
  • Patent number: 11601037
    Abstract: A rectangular-wave-signal generating circuit according to an embodiment comprises: a sawtooth-wave output circuit; a first detector; a second detector; and a first PWM-signal output circuit. The sawtooth-wave output circuit is configured to generate and output a sawtooth-wave signal synchronized with a clock signal. The first detector is configured to detect a first timing at which a potential of the sawtooth-wave signal exceeds a bottom potential. The second detector is configured to detect a second timing at which a potential of the sawtooth-wave signal exceeds a potential of a first pulse-width instruction voltage signal. The first PWM-signal output circuit is configured to generate a first PWM signal based on a time difference between the first timing and the second timing.
    Type: Grant
    Filed: September 11, 2020
    Date of Patent: March 7, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Toshimasa Namekawa
  • Patent number: 11594963
    Abstract: According to one embodiment, a switching power circuit compares a reference voltage with a feedback voltage of an output voltage, and controls the output voltage in accordance with the reference voltage, in which in a case where the output current is greater than a predetermined set current, the voltage of the reference voltage is decreased.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: February 28, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Toshimasa Namekawa, Ryoma Matsuo, Katsumasa Tanaka
  • Patent number: 11290010
    Abstract: According to one embodiment, a switching power circuit, includes: a switching transistor that is connected between an input terminal and a node; a driving circuit that supplies a PWM driving signal to the switching transistor; and a phase compensation circuit that supplies a feedback voltage to an error amplifier, in which the properties of the phase compensation circuit are switched in accordance with the voltage of the node immediately before the switching transistor is turned on.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: March 29, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Toshimasa Namekawa, Ryoma Matsuo, Katsumasa Tanaka
  • Publication number: 20210091656
    Abstract: A rectangular-wave-signal generating circuit according to an embodiment comprises: a sawtooth-wave output circuit; a first detector; a second detector; and a first PWM-signal output circuit. The sawtooth-wave output circuit is configured to generate and output a sawtooth-wave signal synchronized with a clock signal. The first detector is configured to detect a first timing at which a potential of the sawtooth-wave signal exceeds a bottom potential. The second detector is configured to detect a second timing at which a potential of the sawtooth-wave signal exceeds a potential of a first pulse-width instruction voltage signal. The first PWM-signal output circuit is configured to generate a first PWM signal based on a time difference between the first timing and the second timing.
    Type: Application
    Filed: September 11, 2020
    Publication date: March 25, 2021
    Inventor: Toshimasa Namekawa
  • Publication number: 20210083574
    Abstract: According to one embodiment, a switching power circuit, includes: a switching transistor that is connected between an input terminal and a node; a driving circuit that supplies a PWM driving signal to the switching transistor; and a phase compensation circuit that supplies a feedback voltage to an error amplifier, in which the properties of the phase compensation circuit are switched in accordance with the voltage of the node immediately before the switching transistor is turned on.
    Type: Application
    Filed: February 25, 2020
    Publication date: March 18, 2021
    Inventors: Toshimasa Namekawa, Ryoma Matsuo, Katsumasa Tanaka
  • Publication number: 20210067037
    Abstract: According to one embodiment, a switching power circuit compares a reference voltage with a feedback voltage of an output voltage, and controls the output voltage in accordance with the reference voltage, in which in a case where the output current is greater than a predetermined set current, the voltage of the reference voltage is decreased.
    Type: Application
    Filed: March 2, 2020
    Publication date: March 4, 2021
    Inventors: Toshimasa Namekawa, Ryoma Matsuo, Katsumasa Tanaka
  • Patent number: 10871793
    Abstract: According to an embodiment, a constant voltage power source circuit has a voltage feedback circuit that controls an output voltage depending on a control voltage. It has a current feedback circuit that detects an output current, keeps the control voltage at a constant voltage until the output current reaches a predetermined current value, and changes a value of the control voltage at a time when the output current reaches the predetermined current value.
    Type: Grant
    Filed: March 8, 2018
    Date of Patent: December 22, 2020
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventors: Toshimasa Namekawa, Kosuke Tashiro
  • Publication number: 20200304034
    Abstract: A switched-mode power supply according to an embodiment comprises a switching circuit, a smoothing circuit, a differential-signal output circuit, a signal output circuit, a pulse-drive signal output circuit, and a signal generation circuit. The differential-signal output circuit is configured to output a differential signal based on a potential difference between the output voltage and a reference potential. The signal output circuit is configured to generate a signal synchronous. The pulse-drive signal output circuit is configured to adjust a time ratio of outputting the voltage on a basis of a time point when the differential signal and the signal have a same value. The signal generation circuit is configured to generate at least either the differential signal or the signal to cause an interval from a base time in one cycle of the clock signal to the time point to decrease as the input voltage increases.
    Type: Application
    Filed: September 10, 2019
    Publication date: September 24, 2020
    Inventor: Toshimasa Namekawa
  • Publication number: 20190086943
    Abstract: According to an embodiment, a constant voltage power source circuit has a voltage feedback circuit that controls an output voltage depending on a control voltage. It has a current feedback circuit that detects an output current, keeps the control voltage at a constant voltage until the output current reaches a predetermined current value, and changes a value of the control voltage at a time when the output current reaches the predetermined current value.
    Type: Application
    Filed: March 8, 2018
    Publication date: March 21, 2019
    Inventors: Toshimasa Namekawa, Kosuke Tashiro
  • Patent number: 9985549
    Abstract: A DC-DC converter includes a first switch connected between an input node and a switching node, a second switch connected between a reference node and the switching node, a capacitor having a first terminal connected to one of the input node and the reference node, a transformer including a primary coil connected between the switching node and a second terminal of the capacitor, and a secondary coil, a rectification smoothing circuit that rectifies and smooths a voltage of the secondary coil, and a drive circuit. The drive circuit alternately turns on the first and second switches, such that a dead time during which both the first and second switches are turned off has a length corresponding to a time period during which a voltage of the switching node is transitioning from a low state to a high state or the high state to the low state.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: May 29, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshimasa Namekawa
  • Publication number: 20170077821
    Abstract: A DC-DC converter includes a first switch connected between an input node and a switching node, a second switch connected between a reference node and the switching node, a capacitor having a first terminal connected to one of the input node and the reference node, a transformer including a primary coil connected between the switching node and a second terminal of the capacitor, and a secondary coil, a rectification smoothing circuit that rectifies and smooths a voltage of the secondary coil, and a drive circuit. The drive circuit alternately turns on the first and second switches, such that a dead time during which both the first and second switches are turned off has a length corresponding to a time period during which a voltage of the switching node is transitioning from a low state to a high state or the high state to the low state.
    Type: Application
    Filed: September 1, 2016
    Publication date: March 16, 2017
    Inventor: Toshimasa NAMEKAWA
  • Patent number: 8928302
    Abstract: A first added signal that is acquired by adding a reference current signal that is in proportion to a current flowing through an inductance element, a slope compensation signal and a voltage difference signal that is in proportion to a difference between an input voltage and an output voltage and a second added signal that is acquired by adding the reference current signal and the slope compensation signal are compared with a difference signal of a voltage that is in proportion to the output voltage and a predetermined reference voltage, and pulse widths of driving pulse signals of a step-down switching circuit and a step-up switching circuit are controlled as a result of the comparison.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: January 6, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshimasa Namekawa
  • Patent number: 8716998
    Abstract: A DC-DC converter has a switching element, a lowpass filter, an oscillator, an AD converter, an error signal generator, a counter, a comparator, a selector configured to select one of the plurality of clock signals in accordance with a value of a lower side bit of the error signal in sync with a timing when the comparator detects coincidence, and a switching controller configured to control ON/OFF of the switching element in accordance with the clock signal selected by the selector. The selector selects one among the plurality of clock signals and a new clock signal generated by combining two or more clock signals comprising neighboring phases among the plurality of clock signals.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: May 6, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshimasa Namekawa, Daisuke Miyashita, Jun Deguchi
  • Publication number: 20140084882
    Abstract: A first added signal that is acquired by adding a reference current signal that is in proportion to a current flowing through an inductance element, a slope compensation signal and a voltage difference signal that is in proportion to a difference between an input voltage and an output voltage and a second added signal that is acquired by adding the reference current signal and the slope compensation signal are compared with a difference signal of a voltage that is in proportion to the output voltage and a predetermined reference voltage, and pulse widths of driving pulse signals of a step-down switching circuit and a step-up switching circuit are controlled as a result of the comparison.
    Type: Application
    Filed: February 28, 2013
    Publication date: March 27, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Toshimasa NAMEKAWA
  • Patent number: 8279700
    Abstract: A semiconductor device includes a first terminal, a second terminal, and a fuse link that connects between the first terminal and the second terminal. The first terminal and the fuse link have a polysilicon layer doped with an impurity ion and a layer containing a metal element laminated on the polysilicon layer. The second terminal has a polysilicon layer not doped with an impurity ion and a layer containing a metal element laminated on the polysilicon layer, in at least a part of an end side connected to the fuse link.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: October 2, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Osamu Wada, Toshimasa Namekawa
  • Publication number: 20120242314
    Abstract: A DC-DC converter has a switching element, a lowpass filter, an oscillator, an AD converter, an error signal generator, a counter, a comparator, a selector configured to select one of the plurality of clock signals in accordance with a value of a lower side bit of the error signal in sync with a timing when the comparator detects coincidence, and a switching controller configured to control ON/OFF of the switching element in accordance with the clock signal selected by the selector. The selector selects one among the plurality of clock signals and a new clock signal generated by combining two or more clock signals comprising neighboring phases among the plurality of clock signals.
    Type: Application
    Filed: October 3, 2011
    Publication date: September 27, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshimasa Namekawa, Daisuke Miyashita, Jun Deguchi
  • Patent number: 8130562
    Abstract: A semiconductor memory device includes n stages of memory cell units, sense amplifier units, and shift registers. N units of the shift registers are connected to one another on the left end sides. The signal processing units and the reversed signal processing units are disposed adjacent to one another in each of the n units of the shift registers. The signal processing units located on the odd-numbered positions counted from the input end side are connected to one another. The reversed signal processing units located on the even-numbered positions counted from the input end side are connected to one another. The signal processing units located on the end opposite to the input end side are connected to the reversed signal processing units located on the end opposite to the input end side. Each of the signal processing units includes the logic circuit unit and the flip-flop while each of the reversed signal processing units includes the reversed logic circuit unit and the reversed flip-flop.
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: March 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daichi Kaku, Toshimasa Namekawa
  • Patent number: 8120974
    Abstract: A nonvolatile semiconductor memory device comprising: a memory cell array in which two bit lines are provided to each one bit of input data, and memory cells each including an anti-fuse element are arranged at an intersection point between one of the two bit lines and an even address word line, and an intersection point between the other one of the two bit lines and an odd address word line, respectively; a plurality of booster circuits which are arranged in a plurality of memory banks, respectively, and each of which generates a write voltage and a read voltage to be supplied to a corresponding one of the anti-fuse elements of the respective memory banks, each of the memory banks obtained by dividing the memory cell array; a booster circuit controller to issue an instruction to generate the write voltage and the read voltage to the plurality of booster circuits; a word line selector to activate a different word line at the time of writing from one to be activated at the time of reading, with respect to the s
    Type: Grant
    Filed: January 20, 2010
    Date of Patent: February 21, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kensuke Matsufuji, Toshimasa Namekawa