Patents by Inventor Tomiyuki Nagai

Tomiyuki Nagai 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: 11549972
    Abstract: A voltage detection circuit including a voltage input terminal, a voltage dividing circuit, a voltage comparison circuit, an output terminal, a detection voltage adjustment terminal, a voltage-current conversion circuit, and a constant current source. A voltage to be monitored is input to the voltage input terminal. The voltage dividing circuit includes series resistors between the voltage input terminal and a constant voltage terminal. The voltage comparison circuit compares a voltage divided by the voltage dividing circuit with a predetermined voltage. The comparison result is output from the output terminal. An external resistor is connected to the detection voltage adjustment terminal. The voltage-current conversion circuit is provided between the detection voltage adjustment terminal and the voltage dividing circuit. The constant current source is connected between an internal power supply voltage terminal and the detection voltage adjustment terminal.
    Type: Grant
    Filed: February 26, 2021
    Date of Patent: January 10, 2023
    Assignee: MITSUMI ELECTRIC CO., LTD.
    Inventors: Hitoshi Tabuchi, Masaru Hirai, Tomiyuki Nagai, Kenya Tokuda
  • Publication number: 20210293859
    Abstract: A voltage detection circuit including a voltage input terminal, a voltage dividing circuit, a voltage comparison circuit, an output terminal, a detection voltage adjustment terminal, a voltage-current conversion circuit, and a constant current source. A voltage to be monitored is input to the voltage input terminal. The voltage dividing circuit includes series resistors between the voltage input terminal and a constant voltage terminal. The voltage comparison circuit compares a voltage divided by the voltage dividing circuit with a predetermined voltage. The comparison result is output from the output terminal. An external resistor is connected to the detection voltage adjustment terminal. The voltage-current conversion circuit is provided between the detection voltage adjustment terminal and the voltage dividing circuit. The constant current source is connected between an internal power supply voltage terminal and the detection voltage adjustment terminal.
    Type: Application
    Filed: February 26, 2021
    Publication date: September 23, 2021
    Applicant: MITSUMI ELECTRIC CO., LTD.
    Inventors: Hitoshi TABUCHI, Masaru HIRAI, Tomiyuki NAGAI, Kenya TOKUDA
  • Patent number: 8674677
    Abstract: A semiconductor integrated circuit includes a current mirror having a predetermined input-output ratio and including a first transistor configured to receive an input current and a second transistor configured to output an output current, and an output transistor configured to generate a reference voltage according to the output current of the current mirror. The value of the output current is greater than the value of the input current, and the total area of one or more collector regions of the first transistor is substantially the same as the total area of one or more collector regions of the second transistor.
    Type: Grant
    Filed: July 22, 2011
    Date of Patent: March 18, 2014
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Takehito Mishima, Tomiyuki Nagai
  • Patent number: 8183715
    Abstract: A reverse current preventing circuit of an N channel type switching MOS transistor connected between a voltage input terminal and an output terminal to control a conduction state between the voltage input terminal and the output terminal, the circuit comprises: a first MOS transistor connected between a substrate of the switching MOS transistor and a ground point; and a second MOS transistor connected between the substrate of the switching MOS transistor and a point having a piece of predetermined constant potential higher than that of the ground point, wherein the piece of predetermined constant potential higher than that of the ground point is applied to the substrate of the switching MOS transistor while the switching MOS transistor is made to be in its on-state, and ground potential is applied to the substrate of the switching MOS transistor while the switching MOS transistor is made to be in its off-state.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: May 22, 2012
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Daisuke Hanawa, Osamu Kawagoe, Tomiyuki Nagai, Hitoshi Tabuchi
  • Publication number: 20120043952
    Abstract: A semiconductor integrated circuit includes a current mirror having a predetermined input-output ratio and including a first transistor configured to receive an input current and a second transistor configured to output an output current, and an output transistor configured to generate a reference voltage according to the output current of the current mirror. The value of the output current is greater than the value of the input current, and the total area of one or more collector regions of the first transistor is substantially the same as the total area of one or more collector regions of the second transistor.
    Type: Application
    Filed: July 22, 2011
    Publication date: February 23, 2012
    Applicant: MITSUMI ELECTRIC CO., LTD.
    Inventors: Takehito Mishima, Tomiyuki Nagai
  • Publication number: 20100225169
    Abstract: A reverse current preventing circuit of an N channel type switching MOS transistor connected between a voltage input terminal and an output terminal to control a conduction state between the voltage input terminal and the output terminal, the circuit comprises: a first MOS transistor connected between a substrate of the switching MOS transistor and a ground point; and a second MOS transistor connected between the substrate of the switching MOS transistor and a point having a piece of predetermined constant potential higher than that of the ground point, wherein the piece of predetermined constant potential higher than that of the ground point is applied to the substrate of the switching MOS transistor while the switching MOS transistor is made to be in its on-state, and ground potential is applied to the substrate of the switching MOS transistor while the switching MOS transistor is made to be in its off-state.
    Type: Application
    Filed: March 4, 2010
    Publication date: September 9, 2010
    Applicant: MITSUMI ELECTRIC CO., LTD.
    Inventors: Daisuke Hanawa, Osamu Kawagoe, Tomiyuki Nagai, Hitoshi Tabuchi
  • Publication number: 20100194369
    Abstract: A switching control circuit for controlling on/off of a switching element for driving an inductor for voltage conversion, the switching control circuit including: a voltage comparator for determining whether an output voltage of the inductor is in a first state where the output voltage is equal to or higher than a predetermined electric potential or in a second state where the output voltage is lower than the predetermined electric potential; a timing determination unit for determining an on-timing to turn on the switching element based on a clock signal having a predetermined frequency even when the output voltage is in the first state; and a drive control circuit for generating a driving signal to turn on or turn off the switching element based on an output signal of the timing determination unit.
    Type: Application
    Filed: January 28, 2010
    Publication date: August 5, 2010
    Applicant: Mitsumi Electric Co. Ltd.
    Inventors: Tomiyuki NAGAI, Yoshihiro Takahashi
  • Patent number: 7205727
    Abstract: A power supply circuit is disclosed that includes a coil with first and second ends having supply voltage applied to the first end, a first switching element connected between the second end of the coil and ground, a second switching or diode element supplying current to a load after rectifying the current in accordance with voltage generated at the connection of the coil and the first switching element, a driver circuit switching at least the first switching element, a third switching element connected in series to the load, and a power supply stop circuit switching off the first element so as to stop supplying power to the load and switching off the third element so as to stop supplying the current to the load in accordance with an external signal.
    Type: Grant
    Filed: November 9, 2004
    Date of Patent: April 17, 2007
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Junji Takeshita, Masayuki Suzuki, Keisuke Yamazato, Tomomitsu Ohara, Tomiyuki Nagai, Naoshi Tokuda
  • Publication number: 20050169022
    Abstract: A power supply circuit is disclosed that includes a coil with first and second ends having supply voltage applied to the first end, a first switching element connected between the second end of the coil and ground, a second switching or diode element supplying current to a load after rectifying the current in accordance with voltage generated at the connection of the coil and the first switching element, a driver circuit switching at least the first switching element, a third switching element connected in series to the load, and a power supply stop circuit switching off the first element so as to stop supplying power to the load and switching off the third element so as to stop supplying the current to the load in accordance with an external signal.
    Type: Application
    Filed: November 9, 2004
    Publication date: August 4, 2005
    Inventors: Junji Takeshita, Masayuki Suzuki, Keisuke Yamazato, Tomomitsu Ohara, Tomiyuki Nagai, Naoshi Tokuda