Patents by Inventor Tetsuya Makihara

Tetsuya Makihara 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: 20220239258
    Abstract: An amplifier circuit includes a main amplifier and an auxiliary circuit that improves a slew rate of the main amplifier. The main amplifier is composed of a one-stage CMOS amplifier, amplifies a voltage difference between two input signals, and outputs, from output terminals, an output signal corresponding to the voltage difference of the input signals. The auxiliary circuit controls an auxiliary bias current flowing through the output terminals according to the voltage difference of the input signals, and interrupts the auxiliary bias current at a predetermined timing before completion of settling. Such a scheme enables improvement of a slew rate by the auxiliary circuit and high-speed operation as well as reduction of error due to mismatch between the main amplifier and the auxiliary circuit, thereby yielding high-accuracy output signal output therefrom.
    Type: Application
    Filed: January 18, 2022
    Publication date: July 28, 2022
    Inventors: Shogo KAWAHARA, Tetsuya MAKIHARA, Takeshi MORINAGA
  • Patent number: 10274544
    Abstract: A route switching circuit includes: a pair of normal detection routes that output voltages of a positive side connection point and a negative side connection point, which are different from each other, in multiple batteries for constituting an assembled battery; and a pair of diagnosis detection routes that output the voltages of the positive side connection point and the negative side connection point, and confirm a connection state of the normal detection routes by using the normal detection routes, which output at least one of a voltage of a positive side battery connected to a positive side from the positive side connection point and a voltage of a negative side battery connected to a negative side from the negative side connection point.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: April 30, 2019
    Assignee: DENSO CORPORATION
    Inventors: Yukihiro Tomonaga, Tetsuya Makihara, Kazutaka Honda, Nobuyoshi Osamura, Ryotaro Miura
  • Patent number: 9678166
    Abstract: A first part circuit and an operational amplifier form a level shift circuit, which selects either one of battery cells forming an assembled battery and extracts and holds a voltage representing an inter-terminal voltage of a selected battery cell. A second part circuit and the operational amplifier form a residual voltage generation circuit, which generates a residual voltage by amplifying a differential voltage between a conversion subject voltage and an analog voltage corresponding to a conversion result of an A/D conversion circuit and applies the residual voltage to the A/D conversion circuit as a conversion subject voltage. A switchover circuit operates the operational amplifier as either one of the level shift circuit and the residual voltage generation circuit and switches over a connection-state to apply a voltage held by the level shift circuit to the A/D conversion circuit and the residual voltage generation circuit as a conversion subject voltage.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: June 13, 2017
    Assignee: DENSO CORPORATION
    Inventors: Kazutaka Honda, Tetsuya Makihara, Shogo Hikosaka
  • Patent number: 9465083
    Abstract: In a voltage detecting device, a control unit turns on first switches and fifth switches corresponding to a plurality of unit batteries of an assembled battery to charge electric charge to first capacitors. The control unit simultaneously turns off at least one of the first switches or the fifth switches to hold the electric charge in the first capacitors. While selecting one of the unit batteries in a predetermined order as a target unit battery for voltage detection, the control unit temporarily turns off a fourth switch to reset electric charge of a second capacitor, and then turns of second switches and third switches in a state where one of the first switches and one of the fifth switches corresponding to the target unit battery are kept in an off state, thereby to detect a voltage of the target unit battery.
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: October 11, 2016
    Assignee: DENSO CORPORATION
    Inventors: Tetsuya Makihara, Kazutaka Honda, Kazunori Nagaya
  • Publication number: 20150153422
    Abstract: A first part circuit and an operational amplifier form a level shift circuit, which selects either one of battery cells forming an assembled battery and extracts and holds a voltage representing an inter-terminal voltage of a selected battery cell. A second part circuit and the operational amplifier form a residual voltage generation circuit, which generates a residual voltage by amplifying a differential voltage between a conversion subject voltage and an analog voltage corresponding to a conversion result of an A/D conversion circuit and applies the residual voltage to the A/D conversion circuit as a conversion subject voltage. A switchover circuit operates the operational amplifier as either one of the level shift circuit and the residual voltage generation circuit and switches over a connection-state to apply a voltage held by the level shift circuit to the A/D conversion circuit and the residual voltage generation circuit as a conversion subject voltage.
    Type: Application
    Filed: November 25, 2014
    Publication date: June 4, 2015
    Inventors: Kazutaka HONDA, Tetsuya MAKIHARA, Shogo HIKOSAKA
  • Publication number: 20150054519
    Abstract: A route switching circuit includes: a pair of normal detection routes that output voltages of a positive side connection point and a negative side connection point, which are different from each other, in multiple batteries for constituting an assembled battery; and a pair of diagnosis detection routes that output the voltages of the positive side connection point and the negative side connection point, and confirm a connection state of the normal detection routes by using the normal detection routes, which output at least one of a voltage of a positive side battery connected to a positive side from the positive side connection point and a voltage of a negative side battery connected to a negative side from the negative side connection point.
    Type: Application
    Filed: July 29, 2014
    Publication date: February 26, 2015
    Inventors: Yukihiro TOMONAGA, Tetsuya MAKIHARA, Kazutaka HONDA, Nobuyoshi OSAMURA, Ryotaro MIURA
  • Patent number: 8890565
    Abstract: A logic signal transmission circuit includes a driving circuit, an isolation section, and a latch section. The driving circuit converts an input digital signal to a differential digital signal. The isolation section blocks direct current and passes the differential digital signal. The latch section has even numbers of inverters which are connected in a loop and output a logic signal by turning ON and OFF a power supply voltage in a complementary manner. An input impedance of the latch section is set so that when a logic level of the differential digital signal changes, a transient voltage inputted through the isolation section to the latch section changes across a threshold voltage of the latch section. When the transient voltage changes across the threshold voltage, a logic level of the logic signal changes.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: November 18, 2014
    Assignee: DENSO CORPORATION
    Inventors: Kazutaka Honda, Tetsuya Makihara
  • Publication number: 20140176148
    Abstract: In a voltage detecting device, a control unit turns on first switches and fifth switches corresponding to a plurality of unit batteries of an assembled battery to charge electric charge to first capacitors. The control unit simultaneously turns off at least one of the first switches or the fifth switches to hold the electric charge in the first capacitors. While selecting one of the unit batteries in a predetermined order as a target unit battery for voltage detection, the control unit temporarily turns off a fourth switch to reset electric charge of a second capacitor, and then turns of second switches and third switches in a state where one of the first switches and one of the fifth switches corresponding to the target unit battery are kept in an off state, thereby to detect a voltage of the target unit battery.
    Type: Application
    Filed: December 18, 2013
    Publication date: June 26, 2014
    Applicant: DENSO CORPORATION
    Inventors: Tetsuya MAKIHARA, Kazutaka HONDA, Kazunori NAGAYA
  • Patent number: 8711536
    Abstract: A voltage detection apparatus includes an operational amplifier, first and second switches coupled between a terminal of a detection target voltage source and a common node, a first capacitor including a plurality of capacitor elements coupled in series between the common node and an inverting input terminal of the operational amplifier, a third switch and a second capacitor, which are coupled between the inverting input terminal and an output terminal of the operational amplifier, a reference voltage selection circuit which applies one of a first reference voltage and a second reference voltage differing from one another to a non-inverting input terminal of the operational amplifier, and a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: April 29, 2014
    Assignee: DENSO CORPORATION
    Inventor: Tetsuya Makihara
  • Patent number: 8692556
    Abstract: An operational amplifier has an input biased at a predetermined reference voltage. A control unit opens both second switches and third switches corresponding to unit batteries being non-detection object, closes fourth switch. The control unit further closes both one of first switches and one of third switches corresponding to one unit battery being a detection object to charge corresponding one of first capacitors. Thereafter, the control unit opens the fourth switch. The control unit further closes one of the second switches corresponding to the one unit battery being the detection object, instead of the one of the first switches. Thus, the control unit detects a voltage of each of the unit batteries.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: April 8, 2014
    Assignee: DENSO CORPORATION
    Inventor: Tetsuya Makihara
  • Patent number: 8405538
    Abstract: A control circuit connects a capacitor to an input terminal and an output terminal of an operational amplifier and applies a signal charge to charge the capacitor with a switch being turned off. Thus, a conversion voltage corresponding to the signal charge is outputted from the operational amplifier. The control circuit then sets charges, which correspond to the conversion voltage, in capacitors and reallocates the charges among the capacitors by connecting non-common electrodes of the capacitors to either one of a plurality of reference voltage lines in accordance with a conversion result of an A/D conversion circuit with the capacitor being connected to the input terminal and the output terminal of the operational amplifier. The control circuit thereafter performs, a number of times, charge setting, initialization and subsequent charge reallocation in accordance with a residual voltage outputted from the operational amplifier.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: March 26, 2013
    Assignee: DENSO CORPORATION
    Inventors: Tetsuya Makihara, Masakiyo Horie, Kazutaka Honda
  • Patent number: 8344929
    Abstract: An A/D converter device is provided, which has a D/A conversion function and changes a resolution of A/D conversion and D/A conversion. The A/D converter device is configured to selectively execute an A/D conversion operation and a D/A conversion operation, by the operation of a control circuit controlling switching of switches according to an ADC/DAC function switching signal supplied from an external side. The A/D conversion operation performs A/D conversion of an input signal voltage inputted via a signal input terminal from an external side and outputs an A/D conversion value of 12 bits. The D/A conversion operation outputs, via a signal output terminal, an analog voltage produced by performing D/A conversion of a digital value supplied from the external side.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: January 1, 2013
    Assignee: DENSO CORPORATION
    Inventors: Tetsuya Makihara, Masakiyo Horie
  • Patent number: 8324968
    Abstract: An amplifier circuit is provided to be switchable between a single end output configuration and a differential output configuration without increasing a circuit area. When first and fourth switches are turned off and a second switch is turned on, a load circuit functions as an active load on a differential pair and a first output terminal is internally disconnected. The amplifier circuit is provided with a single end output configuration and differentially amplifies input voltages inputted to input terminals and outputs an imbalanced signal from a second output terminal. When the first and fourth switches are turned on and the second switch is turned off, the load circuit functions as a load on the differential pair and the first output terminal is internally connected. The amplifier circuit is provided with a differential output configuration and differentially amplifies the input voltages inputted to the input terminals and outputs balanced signals from the output terminals.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: December 4, 2012
    Assignee: DENSO CORPORATION
    Inventors: Kazutaka Honda, Tetsuya Makihara, Masakiyo Horie
  • Publication number: 20120250203
    Abstract: A voltage detection apparatus includes an operational amplifier, first and second switches coupled between a terminal of a detection target voltage source and a common node, a first capacitor including a plurality of capacitor elements coupled in series between the common node and an inverting input terminal of the operational amplifier, a third switch and a second capacitor, which are coupled between the inverting input terminal and an output terminal of the operational amplifier, a reference voltage selection circuit which applies one of a first reference voltage and a second reference voltage differing from one another to a non-inverting input terminal of the operational amplifier, and a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode.
    Type: Application
    Filed: March 19, 2012
    Publication date: October 4, 2012
    Applicant: DENSO CORPORATION
    Inventor: Tetsuya Makihara
  • Publication number: 20120139545
    Abstract: An operational amplifier has an input biased at a predetermined reference voltage. A control unit opens both second switches and third switches corresponding to unit batteries being non-detection object, closes fourth switch. The control unit further closes both one of first switches and one of third switches corresponding to one unit battery being a detection object to charge corresponding one of first capacitors. Thereafter, the control unit opens the fourth switch. The control unit further closes one of the second switches corresponding to the one unit battery being the detection object, instead of the one of the first switches. Thus, the control unit detects a voltage of each of the unit batteries.
    Type: Application
    Filed: November 30, 2011
    Publication date: June 7, 2012
    Applicant: DENSO CORPORATION
    Inventor: Tetsuya MAKIHARA
  • Publication number: 20110254716
    Abstract: An A/D converter device is provided, which has a D/A conversion function and changes a resolution of A/D conversion and D/A conversion. The A/D converter device is configured to selectively execute an A/D conversion operation and a D/A conversion operation, by the operation of a control circuit controlling switching of switches according to an ADC/DAC function switching signal supplied from an external side. The A/D conversion operation performs A/D conversion of an input signal voltage inputted via a signal input terminal from an external side and outputs an A/D conversion value of 12 bits. The D/A conversion operation outputs, via a signal output terminal, an analog voltage produced by performing D/A conversion of a digital value supplied from the external side.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 20, 2011
    Applicant: DENSO CORPORATION
    Inventors: Tetsuya MAKIHARA, Masakiyo Horie
  • Publication number: 20110241780
    Abstract: An amplifier circuit is provided to be switchable between a single end output configuration and a differential output configuration without increasing a circuit area. When first and fourth switches are turned off and a second switch is turned on, a load circuit functions as an active load on a differential pair and a first output terminal is internally disconnected. The amplifier circuit is provided with a single end output configuration and differentially amplifies input voltages inputted to input terminals and outputs an imbalanced signal from a second output terminal. When the first and fourth switches are turned on and the second switch is turned off, the load circuit functions as a load on the differential pair and the first output terminal is internally connected. The amplifier circuit is provided with a differential output configuration and differentially amplifies the input voltages inputted to the input terminals and outputs balanced signals from the output terminals.
    Type: Application
    Filed: March 30, 2011
    Publication date: October 6, 2011
    Applicant: DENSO CORPORATION
    Inventors: Kazutaka HONDA, Tetsuya Makihara, Masakiyo Horie
  • Publication number: 20110234441
    Abstract: A control circuit connects a capacitor to an input terminal and an output terminal of an operational amplifier and applies a signal charge to charge the capacitor with a switch being turned off. Thus, a conversion voltage corresponding to the signal charge is outputted from the operational amplifier. The control circuit then sets charges, which correspond to the conversion voltage, in capacitors and reallocates the charges among the capacitors by connecting non-common electrodes of the capacitors to either one of a plurality of reference voltage lines in accordance with a conversion result of an A/D conversion circuit with the capacitor being connected to the input terminal and the output terminal of the operational amplifier. The control circuit thereafter performs, a number of times, charge setting, initialization and subsequent charge reallocation in accordance with a residual voltage outputted from the operational amplifier.
    Type: Application
    Filed: March 17, 2011
    Publication date: September 29, 2011
    Applicant: DENSO CORPORATION
    Inventors: Tetsuya MAKIHARA, Masakiyo Horie, Kazutaka Honda
  • Patent number: 7746254
    Abstract: A sample and hold circuit includes an op-amp, inverting-side capacitors, and non-inverting-side capacitors paired with the inverting-side capacitors. At least one capacitor pair serves as a feedback capacitor in a holding phase. A total capacitance of the inverting-side capacitors to which an input voltage is applied in a sampling phase is ?, a total capacitance of the non-inverting-side capacitors to which the input voltage is applied in the sampling phase is ?, a total capacitance of the inverting-side capacitors to which the input voltage is applied in a holding phase is ?, and a total capacitance of the non-inverting-side capacitors to which the input voltage is applied in the holding phase is ?. ? is substantially different from ?. A total capacitance of a feedback capacitor pair is substantially equal to (?????+?)·(N/2), where N is a positive number.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: June 29, 2010
    Assignee: DENSO CORPORATION
    Inventors: Tetsuya Makihara, Masakiyo Horie
  • Publication number: 20090167582
    Abstract: A sample and hold circuit includes an op-amp, inverting-side capacitors, and non-inverting-side capacitors paired with the inverting-side capacitors. At least one capacitor pair serves as a feedback capacitor in a holding phase. A total capacitance of the inverting-side capacitors to which an input voltage is applied in a sampling phase is ?, a total capacitance of the non-inverting-side capacitors to which the input voltage is applied in the sampling phase is ?, a total capacitance of the inverting-side capacitors to which the input voltage is applied in a holding phase is ?, and a total capacitance of the non-inverting-side capacitors to which the input voltage is applied in the holding phase is ?. ? is substantially different from ?. A total capacitance of a feedback capacitor pair is substantially equal to (?????+?)·(N/2), where N is a positive number.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Applicant: DENSO CORPORATION
    Inventors: Tetsuya Makihara, Masakiyo Horie