Patents by Inventor Toshio Nagasawa

Toshio Nagasawa 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: 20230421153
    Abstract: According to one embodiment, semiconductor integrated circuit includes a first switch circuit, a second switch circuit, a correction circuit and a comparison circuit. The first switch circuit is configured to output or interrupt a first voltage in accordance with a first signal. The second switch circuit is configured to output or interrupt a second voltage in accordance with a second signal. The correction circuit is configured to correct the second signal and output a third signal. The comparison circuit is configured to compare the third signal output from the correction circuit with the first voltage and determine the first signal based on a result of comparison.
    Type: Application
    Filed: March 6, 2023
    Publication date: December 28, 2023
    Inventors: Toshio NAGASAWA, Naotaka KOIDE
  • Patent number: 10886842
    Abstract: A power supply circuit according to an embodiment includes an driver, a control circuit, and a protection circuit. The driver includes a first transistor connected between a high-potential-side power supply and a node and a second transistor connected between a low-potential-side power supply and the node. The control circuit generates, according to an output voltage to a load connected to the node via a first low-pass filter circuit, first and second switching pulses for alternately switching the first and second transistors. The protection circuit outputs, when a voltage of the node via a second low-pass filter circuit exceeds a first reference voltage, an interruption signal for making at least the first transistor nonconductive.
    Type: Grant
    Filed: August 30, 2019
    Date of Patent: January 5, 2021
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Toshio Nagasawa, Takuya Hirakawa
  • Publication number: 20200295656
    Abstract: A power supply circuit according to an embodiment includes an driver, a control circuit, and a protection circuit. The driver includes a first transistor connected between a high-potential-side power supply and a node and a second transistor connected between a low-potential-side power supply and the node. The control circuit generates, according to an output voltage to a load connected to the node via a first low-pass filter circuit, first and second switching pulses for alternately switching the first and second transistors. The protection circuit outputs, when a voltage of the node via a second low-pass filter circuit exceeds a first reference voltage, an interruption signal for making at least the first transistor nonconductive.
    Type: Application
    Filed: August 30, 2019
    Publication date: September 17, 2020
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Toshio NAGASAWA, Takuya HIRAKAWA
  • Patent number: 9685865
    Abstract: A power-supply apparatus according to an aspect includes an inductor, a transistor that supplies, in an on-state, a current to the input side of the inductor, a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential, a signal generation unit that generates voltage signals corresponding to a current flowing to the inductor, an amplifier that outputs a current according to the voltage signals, a converter that converts the current output from the amplifier into a voltage signal, and a control unit that controls the transistors based on a first feedback signal corresponding to the voltage on the output side of the inductor and the voltage signal, which is used as a second feedback signal.
    Type: Grant
    Filed: May 14, 2015
    Date of Patent: June 20, 2017
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Toshio Nagasawa, Yoshitaka Onaya, Koji Saikusa, Shin Chiba
  • Patent number: 9369045
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: June 14, 2016
    Assignee: Renesas Electronics Corporation
    Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Patent number: 9276462
    Abstract: Provided is a controller that is capable of reducing fall in a waveform of a power supply voltage when the power supply voltage supplied to a CPU is reduced. A controller for controlling voltage regulators includes a differential amplifier that outputs a measurement voltage corresponding to a power supply voltage supplied to a load and an error amplifier having a non-inverting input terminal supplied with a target voltage and an inverting input terminal supplied with a measurement voltage. The error amplifier compares the target voltage and the measurement voltage and outputs a signal for controlling the voltage regulators. Further included in the controller is a correction circuit that applies an offset voltage to the inverting input terminal of the error amplifier when the power supply voltage supplied to the load is reduced.
    Type: Grant
    Filed: September 14, 2013
    Date of Patent: March 1, 2016
    Assignee: Renesas Electronics Corporation
    Inventors: Hiroshi Murakami, Tetsuo Ichino, Shigeru Kurita, Toshio Nagasawa, Takuya Makise
  • Publication number: 20150249387
    Abstract: A power-supply apparatus according to an aspect includes an inductor, a transistor that supplies, in an on-state, a current to the input side of the inductor, a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential, a signal generation unit that generates voltage signals corresponding to a current flowing to the inductor, an amplifier that outputs a current according to the voltage signals, a converter that converts the current output from the amplifier into a voltage signal, and a control unit that controls the transistors based on a first feedback signal corresponding to the voltage on the output side of the inductor and the voltage signal, which is used as a second feedback signal.
    Type: Application
    Filed: May 14, 2015
    Publication date: September 3, 2015
    Inventors: Toshio NAGASAWA, Yoshitaka ONAYA, Koji SAIKUSA, Shin CHIBA
  • Patent number: 9054583
    Abstract: A power-supply apparatus according to an aspect includes an inductor, a transistor that supplies, in an on-state, a current to the input side of the inductor, a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential, a signal generation unit that generates voltage signals corresponding to a current flowing to the inductor, an amplifier that outputs a current according to the voltage signals, a converter that converts the current output from the amplifier into a voltage signal, and a control unit that controls the transistors based on a first feedback signal corresponding to the voltage on the output side of the inductor and the voltage signal, which is used as a second feedback signal.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: June 9, 2015
    Assignee: Renesas Electronics Corporation
    Inventors: Toshio Nagasawa, Yoshitaka Onaya, Koji Saikusa, Shin Chiba
  • Publication number: 20140191737
    Abstract: A power-supply apparatus according to an aspect includes an inductor, a transistor that supplies, in an on-state, a current to the input side of the inductor, a second transistor that becomes, when the first transistor is in an off-state, an on-state and thereby brings the input side of the inductor to a predetermined potential, a signal generation unit that generates voltage signals corresponding to a current flowing to the inductor, an amplifier that outputs a current according to the voltage signals, a converter that converts the current output from the amplifier into a voltage signal, and a control unit that controls the transistors based on a first feedback signal corresponding to the voltage on the output side of the inductor and the voltage signal, which is used as a second feedback signal.
    Type: Application
    Filed: December 4, 2013
    Publication date: July 10, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Toshio NAGASAWA, Yoshitaka ONAYA, Koji SAIKUSA, Shin CHIBA
  • Publication number: 20140152282
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Application
    Filed: November 19, 2013
    Publication date: June 5, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Kyoichi HOSOKAWA, Ryotaro KUDO, Toshio NAGASAWA, Koji TATENO
  • Publication number: 20140077781
    Abstract: Provided is a controller that is capable of reducing fall in a waveform of a power supply voltage when the power supply voltage supplied to a CPU is reduced. A controller for controlling voltage regulators includes a differential amplifier that outputs a measurement voltage corresponding to a power supply voltage supplied to a load and an error amplifier having a non-inverting input terminal supplied with a target voltage and an inverting input terminal supplied with a measurement voltage. The error amplifier compares the target voltage and the measurement voltage and outputs a signal for controlling the voltage regulators. Further included in the controller is a correction circuit that applies an offset voltage to the inverting input terminal of the error amplifier when the power supply voltage supplied to the load is reduced.
    Type: Application
    Filed: September 14, 2013
    Publication date: March 20, 2014
    Inventors: Hiroshi Murakami, Tetsuo Ichino, Shigeru Kurita, Toshio Nagasawa, Takuya Makise
  • Publication number: 20140032942
    Abstract: A voltage regulator has a voltage converter circuit and a control unit. The control unit controls the voltage converter circuit so that an output voltage attains a target voltage when the voltage regulator is in a no-load condition so as to have a transition characteristic in which the output voltage decreases with increase in the load current. The control unit calculates deviation between the output voltage and an ideal value thereof when a load condition of the voltage regulator is a first load condition, and corrects the target voltage by the output voltage adjustment unit. so The control unit also calculates deviation between rate of change of the output voltage with respect to the load current and an ideal value thereof, and corrects the transition characteristic so that the deviation becomes small to minimize deviation.
    Type: Application
    Filed: July 29, 2013
    Publication date: January 30, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Yuji TAKEHARA, Koji SAIKUSA, Ryotaro KUDO, Toshio NAGASAWA
  • Patent number: 8604764
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: December 10, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Patent number: 8497666
    Abstract: A multi-phase power source device capable of easily changing the number of phases is realized. For example, a plurality of drive units POL[1]-POL[4] corresponding to the number of phases are provided, wherein each POL[n] receives a phase input signal PHI[n] serving as a pulse signal, and generates a phase output signal PHO[n] by delaying PHI[n] by a predetermined cycles of a clock signal CLK. PHI[n] and PHO[n] of each POL[n] are coupled in a ring, wherein each POL[n] performs a switching operation with PHI[n] or PHO[n] as a starting point. In this case, each POL[n] charges and discharges a capacitor Cct commonly coupled to each POL[n] with an equal current, and a frequency of CLK is determined based on this charge and discharge rate. That is, if the number of phases increases n times, the frequency of CLK will be automatically controlled to n times.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: July 30, 2013
    Assignee: Renesas Electronics Corporation
    Inventor: Toshio Nagasawa
  • Patent number: 8482345
    Abstract: A non-insulated DC-DC converter has a power MOS•FET for a highside switch and a power MOS•FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•FET for the highside switch and the power MOS•FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: July 9, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
  • Patent number: 8471541
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Grant
    Filed: May 11, 2012
    Date of Patent: June 25, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Publication number: 20130002313
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Application
    Filed: September 13, 2012
    Publication date: January 3, 2013
    Inventors: KYOICHI HOSOKAWA, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Publication number: 20120286365
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Application
    Filed: May 11, 2012
    Publication date: November 15, 2012
    Inventors: KYOICHI HOSOKAWA, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Patent number: 8305060
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other such that when the MOSFET is made to assume an OFF state, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: November 6, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Publication number: 20120086062
    Abstract: In a switching power source which controls a current which flows in an inductor through a switching element which performs a switching operation in response to a PWM signal, and forms an output voltage by a capacitor which is provided in series in the inductor, a booster circuit which is constituted of a bootstrap capacity and a MOSFET is provided between an output node of the switching element and a predetermined voltage terminal. The boosted voltage is used as an operational voltage of a driving circuit of the switching element, another source/drain region and a substrate gate are connected with each other such that when the MOSFET is made to assume an OFF state, and a junction diode between one source/drain region and the substrate gate is inversely directed with respect to the boosted voltage which is formed by the bootstrap capacity.
    Type: Application
    Filed: October 11, 2011
    Publication date: April 12, 2012
    Inventors: KYOICHI HOSOKAWA, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno