Patents by Inventor Tetsuo Yamato

Tetsuo Yamato 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: 12119813
    Abstract: Disclosed is a switch device including a first terminal, a second terminal, a third terminal, a switch element disposed between the first terminal and the second terminal, a control line that reaches a control end of the switch element from the third terminal, a first circuit block that is disposed on the control line and is configured to drive the switch element according to a control signal supplied to the third terminal, at least one second circuit block, each second circuit block being connected to a corresponding one of branch power supply lines that branch from the control line, a first resistor disposed between the third terminal and the first circuit block, and at least one second resistor, each second resistor being disposed on a corresponding one of the branch power supply lines.
    Type: Grant
    Filed: October 18, 2022
    Date of Patent: October 15, 2024
    Assignee: ROHM Co., LTD.
    Inventors: Tetsuo Yamato, Shuntaro Takahashi, Kazuki Okuyama
  • Publication number: 20240213977
    Abstract: The present disclosure provides a load driving device. The load driving device includes a load, a resistor configured to be connected in parallel to the load, and a switch device. The switch device includes an output terminal, a ground terminal, a first switch element and an abnormality detection circuit. The output terminal is configured to connect the load and the resistor. The ground terminal is configured to connect to a ground potential. The first switch element is configured to be connected between the output terminal and the ground terminal. The abnormality detection circuit is configured to distinguish between a load open at the output terminal and a ground fault at the output terminal based on a magnitude relationship between an output current flowing through the first switch element, a first threshold value and a second threshold value greater than the first threshold value.
    Type: Application
    Filed: December 21, 2023
    Publication date: June 27, 2024
    Inventor: Tetsuo Yamato
  • Publication number: 20240178836
    Abstract: The present disclosure provides a semiconductor device. The semiconductor device includes: a first terminal; a second terminal; and at least one first switch element and at least one second switch element, configured to be connected between the first terminal and the second terminal; an overcurrent detection circuit, configured to detect an overcurrent flowing through the first terminal; and an off circuit, configured to turn off at least a portion of the at least one second switch element when the semiconductor device is started.
    Type: Application
    Filed: November 17, 2023
    Publication date: May 30, 2024
    Inventor: Tetsuo YAMATO
  • Patent number: 11923834
    Abstract: A switch device includes an output transistor, an overcurrent protection circuit configured to be capable of performing an overcurrent protection operation in which magnitude of target current flowing in the output transistor is limited to a predetermined upper limit current value or less, and a control circuit configured to be capable of controlling a state of the output transistor and capable of changing the upper limit current value among a plurality of current values including a predetermined first current value and a predetermined second current value less than the first current value. The control circuit can limit the magnitude of the target current to the first current value or less in response to the magnitude of the target current reaching the first current value, and then change the upper limit current value to the second current value.
    Type: Grant
    Filed: June 1, 2022
    Date of Patent: March 5, 2024
    Assignee: Rohm Co., Ltd.
    Inventor: Tetsuo Yamato
  • Publication number: 20230125777
    Abstract: Disclosed is a switch device including a first terminal, a second terminal, a third terminal, a switch element disposed between the first terminal and the second terminal, a control line that reaches a control end of the switch element from the third terminal, a first circuit block that is disposed on the control line and is configured to drive the switch element according to a control signal supplied to the third terminal, at least one second circuit block, each second circuit block being connected to a corresponding one of branch power supply lines that branch from the control line, a first resistor disposed between the third terminal and the first circuit block, and at least one second resistor, each second resistor being disposed on a corresponding one of the branch power supply lines.
    Type: Application
    Filed: October 18, 2022
    Publication date: April 27, 2023
    Inventors: Tetsuo Yamato, Shuntaro Takahashi, Kazuki Okuyama
  • Patent number: 11539312
    Abstract: The present invention provides a motor driver and a motor driving system capable of suppressing power consumption when a motor is in a brake state. The motor driver of the present invention includes: a half-bridge power output section, including a high-side transistor and a low-side transistor; a high-side driving circuit, driving the high-side transistor; and a control portion. When switching to a brake mode, the low-side transistor is turned on and the control portion turns off the high-side driving circuit.
    Type: Grant
    Filed: July 30, 2020
    Date of Patent: December 27, 2022
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Publication number: 20220399885
    Abstract: A switch device includes an output transistor, an overcurrent protection circuit configured to be capable of performing an overcurrent protection operation in which magnitude of target current flowing in the output transistor is limited to a predetermined upper limit current value or less, and a control circuit configured to be capable of controlling a state of the output transistor and capable of changing the upper limit current value among a plurality of current values including a predetermined first current value and a predetermined second current value less than the first current value. The control circuit can limit the magnitude of the target current to the first current value or less in response to the magnitude of the target current reaching the first current value, and then change the upper limit current value to the second current value.
    Type: Application
    Filed: June 1, 2022
    Publication date: December 15, 2022
    Inventor: Tetsuo Yamato
  • Patent number: 10992294
    Abstract: The present disclosure relates to a driver device, which can drive a load in high temperatures. In a driver IC which drives a motor by switch-driving four output transistors, a gate driving circuit is configured to render a slew rate of a gate voltage of each output transistor to be adjustable at multiple steps while the output transistor is switching. Although a predetermined rate is set to be the slew rate of the gate voltage in a normal state, the slew rate is increased at high temperatures.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: April 27, 2021
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Publication number: 20210044222
    Abstract: The present invention provides a motor driver and a motor driving system capable of suppressing power consumption when a motor is in a brake state. The motor driver of the present invention includes: a half-bridge power output section, including a high-side transistor and a low-side transistor; a high-side driving circuit, driving the high-side transistor; and a control portion. When switching to a brake mode, the low-side transistor is turned on and the control portion turns off the high-side driving circuit.
    Type: Application
    Filed: July 30, 2020
    Publication date: February 11, 2021
    Applicant: ROHM CO., LTD.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Publication number: 20200106433
    Abstract: The present disclosure relates to a driver device, which can drive a load in high temperatures. In a driver IC which drives a motor by switch-driving four output transistors, a gate driving circuit is configured to render a slew rate of a gate voltage of each output transistor to be adjustable at multiple steps while the output transistor is switching. Although a predetermined rate is set to be the slew rate of the gate voltage in a normal state, the slew rate is increased at high temperatures.
    Type: Application
    Filed: September 26, 2019
    Publication date: April 2, 2020
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Patent number: 10516362
    Abstract: A motor driving device includes an abnormality detecting portion arranged to detect an abnormality of one of a plurality of position detection signals based on outputs from a plurality of Hall sensors arranged to detect a rotor position of a brushless DC motor, a measuring portion arranged to measure time between neighboring edges of a normal position detection signal when the abnormality detecting portion detects an abnormality, and a drive control portion arranged to control a drive signal for driving the brushless DC motor based on a latest time measurement result of the measuring portion.
    Type: Grant
    Filed: March 16, 2017
    Date of Patent: December 24, 2019
    Assignee: Rohm Co., Ltd.
    Inventor: Tetsuo Yamato
  • Publication number: 20170272026
    Abstract: A motor driving device includes an abnormality detecting portion arranged to detect an abnormality of one of a plurality of position detection signals based on outputs from a plurality of Hall sensors arranged to detect a rotor position of a brushless DC motor, a measuring portion arranged to measure time between neighboring edges of a normal position detection signal when the abnormality detecting portion detects an abnormality, and a drive control portion arranged to control a drive signal for driving the brushless DC motor based on a latest time measurement result of the measuring portion.
    Type: Application
    Filed: March 16, 2017
    Publication date: September 21, 2017
    Inventor: Tetsuo YAMATO
  • Patent number: 9294020
    Abstract: A motor driving device includes a logic unit configured to control an electrical conduction of a motor, a reference clock signal generating unit configured to generate a reference clock signal based on a rotational speed indication signal, a rotational speed signal generating unit configured to generate a rotational speed signal based on a rotational speed of the motor, and a rotational speed feedback control unit configured to receive the reference clock signal and the rotational speed signal and control the logic unit so that the rotational speed of the motor reaches a target value. The rotational speed feedback control unit changes a feedback gain in response to the rotational speed signal.
    Type: Grant
    Filed: August 4, 2014
    Date of Patent: March 22, 2016
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Patent number: 9197149
    Abstract: A motor drive apparatus comprises: a position signal generation portion that generates a position signal corresponding to a rotor position of a brushless DC motor; and a logic portion that when starting the brushless DC motor, disposes a non-energizing period immediately after starting forced commutation at a phase switchover timing corresponding to a predetermined forced commutation frequency and performs energizing control of the brushless DC motor such that usual commutation is started at a phase switchover timing corresponding to the position signal that is generated during an inertial rotation of the rotor.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: November 24, 2015
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Patent number: 9035582
    Abstract: A motor driving apparatus includes an automatic gain control circuit on a signal path for transmitting a rotor-position detecting signal (hall voltage signal), and the automatic gain control circuit includes: an amplifier, configured to perform differential amplification on an input signal (step-angle hall current signal) to generate an output signal (amplified hall current signal); and a feedback control portion, configured to monitor the output signal (monitored current signal) to decide a gain of the amplifier.
    Type: Grant
    Filed: April 5, 2012
    Date of Patent: May 19, 2015
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Takashi Fujimura
  • Publication number: 20150042250
    Abstract: A motor driving device includes a logic unit configured to control an electrical conduction of a motor, a reference clock signal generating unit configured to generate a reference clock signal based on a rotational speed indication signal, a rotational speed signal generating unit configured to generate a rotational speed signal based on a rotational speed of the motor, and a rotational speed feedback control unit configured to receive the reference clock signal and the rotational speed signal and control the logic unit so that the rotational speed of the motor reaches a target value. The rotational speed feedback control unit changes a feedback gain in response to the rotational speed signal.
    Type: Application
    Filed: August 4, 2014
    Publication date: February 12, 2015
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Publication number: 20140176030
    Abstract: A motor drive apparatus comprises: a position signal generation portion that generates a position signal corresponding to a rotor position of a brushless DC motor; and a logic portion that when starting the brushless DC motor, disposes a non-energizing period immediately after starting forced commutation at a phase switchover timing corresponding to a predetermined forced commutation frequency and performs energizing control of the brushless DC motor such that usual commutation is started at a phase switchover timing corresponding to the position signal that is generated during an inertial rotation of the rotor.
    Type: Application
    Filed: December 5, 2013
    Publication date: June 26, 2014
    Applicant: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Noboru Takizawa
  • Patent number: 8587235
    Abstract: A motor driver includes a control portion, for performing variable control on a torque or rotation speed of a motor through a control signal; and an output mode selection circuit, for sending an indication to the control portion when the control signal is abnormal, so that the motor enters an action status corresponding to a selection signal.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: November 19, 2013
    Assignee: Rohm Co., Ltd.
    Inventors: Tetsuo Yamato, Takashi Fujimara
  • Publication number: 20120262097
    Abstract: A motor driving apparatus includes an automatic gain control circuit on a signal path for transmitting a rotor-position detecting signal (hall voltage signal), and the automatic gain control circuit includes: an amplifier, configured to perform differential amplification on an input signal (step-angle hall current signal) to generate an output signal (amplified hall current signal); and a feedback control portion, configured to monitor the output signal (monitored current signal) to decide a gain of the amplifier.
    Type: Application
    Filed: April 5, 2012
    Publication date: October 18, 2012
    Applicant: ROHM CO., LTD.
    Inventors: Tetsuo Yamato, Takashi Fujimura
  • Publication number: 20120126732
    Abstract: A motor driver includes a control portion, for performing variable control on a torque or rotation speed of a motor through a control signal; and an output mode selection circuit, for sending an indication to the control portion when the control signal is abnormal, so that the motor enters an action status corresponding to a selection signal.
    Type: Application
    Filed: November 22, 2011
    Publication date: May 24, 2012
    Applicant: ROHM CO., LTD.
    Inventors: Tetsuo Yamato, Takashi Fujimura