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).
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Patent number: 11549972Abstract: 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: GrantFiled: February 26, 2021Date of Patent: January 10, 2023Assignee: MITSUMI ELECTRIC CO., LTD.Inventors: Hitoshi Tabuchi, Masaru Hirai, Tomiyuki Nagai, Kenya Tokuda
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Publication number: 20210293859Abstract: 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: ApplicationFiled: February 26, 2021Publication date: September 23, 2021Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Hitoshi TABUCHI, Masaru HIRAI, Tomiyuki NAGAI, Kenya TOKUDA
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Patent number: 8674677Abstract: 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: GrantFiled: July 22, 2011Date of Patent: March 18, 2014Assignee: Mitsumi Electric Co., Ltd.Inventors: Takehito Mishima, Tomiyuki Nagai
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Patent number: 8183715Abstract: 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: GrantFiled: March 4, 2010Date of Patent: May 22, 2012Assignee: Mitsumi Electric Co., Ltd.Inventors: Daisuke Hanawa, Osamu Kawagoe, Tomiyuki Nagai, Hitoshi Tabuchi
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Publication number: 20120043952Abstract: 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: ApplicationFiled: July 22, 2011Publication date: February 23, 2012Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Takehito Mishima, Tomiyuki Nagai
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Publication number: 20100225169Abstract: 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: ApplicationFiled: March 4, 2010Publication date: September 9, 2010Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Daisuke Hanawa, Osamu Kawagoe, Tomiyuki Nagai, Hitoshi Tabuchi
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Publication number: 20100194369Abstract: 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: ApplicationFiled: January 28, 2010Publication date: August 5, 2010Applicant: Mitsumi Electric Co. Ltd.Inventors: Tomiyuki NAGAI, Yoshihiro Takahashi
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Patent number: 7205727Abstract: 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: GrantFiled: November 9, 2004Date of Patent: April 17, 2007Assignee: Mitsumi Electric Co., Ltd.Inventors: Junji Takeshita, Masayuki Suzuki, Keisuke Yamazato, Tomomitsu Ohara, Tomiyuki Nagai, Naoshi Tokuda
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Publication number: 20050169022Abstract: 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: ApplicationFiled: November 9, 2004Publication date: August 4, 2005Inventors: Junji Takeshita, Masayuki Suzuki, Keisuke Yamazato, Tomomitsu Ohara, Tomiyuki Nagai, Naoshi Tokuda