Patents by Inventor Kazuhiro Murakami

Kazuhiro Murakami 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: 8754881
    Abstract: The operational amplifier according to the present invention has at least one differential input part for generating a voltage signal corresponding to an electric potential difference between a positive-phase input signal and a negative-phase input signal by using a differential pair configured from a pair of transistors; an output part for generating and outputting an output signal of a logic level corresponding to the voltage signal generated by the differential input part; at least one auxiliary current generator for detecting a sudden change in the positive-phase input signal or the negative-phase input signal and generating an auxiliary current; and a drive current generator for adding together a predetermined reference current and the auxiliary current and generating a drive current of the differential input part.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: June 17, 2014
    Assignee: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Publication number: 20140146426
    Abstract: An overvoltage protection portion (14) includes a transistor (P1) that achieves continuity with an input voltage (VIN) used as an output voltage (VOUT) to an internal circuit when the input voltage (VIN) applied to an external terminal (T1) is not in an overvoltage state. The overvoltage protection portion (14) also includes: a transistor (P2) operating as a short circuit that short-circuits the source and the gate of the transistor (P1) and that interrupts the input voltage (VIN) when the input voltage (VIN) is in the overvoltage state; a resistor (R2); and a Zener diode (ZD1). The overvoltage protection portion (14) also includes: a transistor (NTr1) operating as a bypass circuit that supplies a constant output voltage (VOUT) from the external terminal (T1) to the internal circuit when the input voltage (VIN) is brought into the overvoltage state; a resistor (R3); and a Zener diode (ZD2).
    Type: Application
    Filed: June 11, 2012
    Publication date: May 29, 2014
    Applicant: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Publication number: 20140146238
    Abstract: A switching power supply device has a switching controller adapted to generate an output voltage from an input voltage by turning on and off a switching device by a non-linear control method according to a comparison signal and a timer signal, a main comparator adapted to generate the comparison signal by comparing a feedback voltage based on the output voltage with a predetermined reference voltage, a timer adapted to output the timer signal as a one-shot pulse when a predetermined fixed period elapses after the switching device is turned from on to off or vice versa, and a reverse current detector adapted to detect a reverse current to the switching device to forcibly turn off the switching device. The timer and the reverse current detector are turned on at a pulse edge in the comparison signal, and are turned off on ending their respective operation.
    Type: Application
    Filed: October 22, 2013
    Publication date: May 29, 2014
    Applicant: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Publication number: 20140086671
    Abstract: Disclosed is a metal joint having improved electrical characteristics and mechanical strength. A center swaged part (2) formed by putting metal plates (11, 12) on top of each other, cutting the metal plates (11, 12) along a first to a fourth cut lines (L1 to L4), and depressing a part surrounded by the first to the fourth cut lines (L1 to L4). Metal joint parts are formed on cut surfaces of the first to the fourth cut lines (L1 to L4) because the cut surfaces of the first to forth cut lines (L1 to L4) are, while rubbing each other, depressed.
    Type: Application
    Filed: May 10, 2012
    Publication date: March 27, 2014
    Applicant: YAZAKI CORPORATION
    Inventors: Kazuhiro Murakami, Takahiro Ishizawa, Mitsuji Kubota, Akihiro Hayashi
  • Publication number: 20140049237
    Abstract: Provided is a switching power source device in which fluctuation of the switching frequency can be suppressed without impairing the advantages of a non-linear control system. A switching power source device is provided with: switching control units of non-linear control type that generate an output voltage (out) from an input voltage (IN) by performing ON/OFF control of switching elements in accordance with the results of comparing a feedback voltage (FB) and reference voltage (REF); and an ON time setting unit that monitors switching voltage (SW) appearing at one end of the switch terminals, and sets the ON time (Ton) of the switching element in the switching control units based on the duty of the switching voltage (SW).
    Type: Application
    Filed: April 19, 2012
    Publication date: February 20, 2014
    Applicant: ROHM CO., LTD.
    Inventors: Hideo Hara, Yoshio Higashida, Kazuhiro Murakami
  • Publication number: 20140036556
    Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.
    Type: Application
    Filed: October 11, 2013
    Publication date: February 6, 2014
    Applicant: Rohm Co., Ltd.
    Inventors: Kazuhiro Murakami, Mikiya Doi, Yosuke Fukumoto
  • Patent number: 8604769
    Abstract: A switching power source device disclosed in this specification includes a switching power source portion of nonlinear control method to generate an output voltage from an input voltage by performing an ON/OFF control of a switch element according to a comparison result between a feedback voltage and a reference voltage, wherein a ripple component is injected to either one of the feedback voltage and the reference voltage, and an offset control portion to adjust either one of the feedback voltage and the reference voltage for cancelling a DC offset of the output voltage caused by the ripple component.
    Type: Grant
    Filed: May 26, 2011
    Date of Patent: December 10, 2013
    Assignee: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Publication number: 20130314606
    Abstract: A switching power supply device includes: a non-linear control type switching control unit that, in accordance with a result of a comparison between a feedback voltage and a reference voltage, performs on/off control of a switch element, and thereby generates an output voltage from an input voltage; a backflow current detection unit that, upon detecting a backflow current flowing to the switch element, forcibly switches off the switch element; and an on-time setting unit that sets an on-time of the switch element, in a case of the backflow current not being detected, in accordance with a duty of the switch element, and in a case of the backflow current being detected, in accordance with a switch voltage appearing at one end of the switch element or the output voltage.
    Type: Application
    Filed: May 22, 2013
    Publication date: November 28, 2013
    Applicant: Rohm Co., Ltd.
    Inventors: Kazuhiro Murakami, Shinji Kawata
  • Patent number: 8593449
    Abstract: A reference voltage generation circuit of the disclosure includes a first amplifier circuit and a second amplifier circuit. The first amplifier circuit includes a first input stage including two npn transistors or two NMOS transistors having base terminals or gate terminals to which a variable voltage and a predetermined lower limit voltage are inputted. A first output stage includes a pnp transistor or a PMOS transistor having an emitter terminal or a source terminal connected to an output terminal of a reference voltage. A first amplifier stage controls the first output stage for equalizing the higher one of the variable voltage and the lower limit voltage with the reference voltage.
    Type: Grant
    Filed: May 27, 2011
    Date of Patent: November 26, 2013
    Assignee: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Publication number: 20130308061
    Abstract: A switching power supply device has a reference voltage generator for generating a reference voltage, a ripple injector for generating a ripple component by use of a pulse voltage indicating the on/off state of a switching element and injecting the ripple component into the reference voltage, an integrated voltage generator for generating an integrated voltage commensurate with the integrated value of the pulse voltage throughout its on- and off-duty periods, a subtractor for lowering according to the integrated voltage the reference voltage before injection of the ripple component or the supply voltage to a buffer that feeds the ripple injector with the pulse voltage after making its pulse height constant, a comparator for comparing a feedback voltage with the reference voltage after injection of the ripple component, and a switching controller for generating an output voltage from an input voltage by non-linear control by turning on and off the switching element according to the output signal of the compara
    Type: Application
    Filed: May 13, 2013
    Publication date: November 21, 2013
    Inventors: Kazuhiro Murakami, Shinji Kawata, Kiminobu Sato
  • Patent number: 8582259
    Abstract: The semiconductor device according to the present invention has an n-channel output transistor wherein an input voltage is impressed on a drain, and a pulsed switching voltage that corresponds to a switching drive of the transistor is brought out from a source; a bootstrap circuit for generating a boost voltage enhanced by a predetermined electric potential above the switching voltage; an internal circuit for receiving a supply of the boost voltage to generate a switching drive signal, and supplying the signal to a gate of the output transistor; an overvoltage protection circuit for monitoring an electric potential difference between the switching voltage and the boost voltage, and generating an overvoltage detection signal; and a switching element for establishing/blocking electrical conduction between the internal circuit and the end impressed with the boost voltage, in accordance with the overvoltage detection signal.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: November 12, 2013
    Assignee: Rohm Co., Ltd.
    Inventors: Kazuhiro Murakami, Mikiya Doi, Yosuke Fukumoto
  • Publication number: 20130235505
    Abstract: A solenoid control device executes feedback control such that a drive current for a solenoid follows a target current, by driving, through PWM, a MOSFET provided on a power supply line to the solenoid. An overcurrent detection circuit that outputs an overcurrent detection signal when the drive current for the solenoid reaches an overcurrent determination current value is provided, and it is determined whether an overcurrent is generated. Whether a short-circuit occurs between both terminals of the solenoid is determined by monitoring whether the overcurrent detection circuit is repeating an output of the overcurrent detection signal and a stop of the output of the overcurrent detection signal.
    Type: Application
    Filed: February 26, 2013
    Publication date: September 12, 2013
    Applicant: JTEKT CORPORATION
    Inventors: Atsushi TAKESHITA, Hisaaki WAKAO, Kiyoshige KATO, Kazuhiro MURAKAMI
  • Publication number: 20120286756
    Abstract: A switching transistor is arranged between a switching (SW) terminal and the ground terminal. An error amplifier amplifies the difference between the feedback voltage VFB that corresponds to the output voltage VOUT with a predetermined reference voltage VREF so as to generate an error voltage VERR. A pulse modulator generates a pulse signal SP having a duty ratio that is adjusted according to the error voltage VERR. A driver drives a switching transistor according to the pulse signal SP. An overvoltage detection circuit generates an overvoltage protection (OVP) signal which is asserted when the voltage at the switching (SW) terminal becomes higher than a predetermined threshold voltage. When the OVP signal is asserted, a control circuit performs a predetermined protection operation.
    Type: Application
    Filed: May 4, 2012
    Publication date: November 15, 2012
    Applicant: Rohm Co., Ltd.
    Inventors: Nobukazu Tsukiji, Kazuhiro Murakami
  • Publication number: 20120286752
    Abstract: A high-side variable current source and a high-side transistor are provided in series between a supply power terminal of a control circuit and a gate of a switching transistor. A low-side variable current source and a low-side transistor are provided in series between the gate of the switching transistor and a ground terminal. A slew rate controller controls the current value of at least one of the high-side and low-side variable current sources according to the state of a setting terminal. A switching power supply device has a plurality of output transistors connected in parallel with one another and a controller that generates control signals turning on and off the output transistors at a predetermined frequency so as to generate a desired output voltage from an input voltage and supply the output voltage to a load. The controller determines which output transistor to drive according to the magnitude of the load.
    Type: Application
    Filed: May 11, 2012
    Publication date: November 15, 2012
    Applicant: Rohm Co., Ltd.
    Inventors: Nobukazu Tsukiji, Kazuhiro Murakami, Masashi Nagasato, Tadashi Akaho
  • Publication number: 20120229707
    Abstract: A DC/DC converter 10 has a high-side transistor QH as a switching element and a low-side transistor QL as a synchronous rectifier element. A first primary electrode D and secondary primary electrode S of the high-side transistor QH are connected to an input voltage VIN and an external terminal T1, respectively. A detection transistor QD is provided in a row with the high-side transistor QH, and the ON voltage of the high-side transistor QH when ON is output as detection voltage VQD from the detection transistor QD. The output detection voltage VQD is added to a feedback voltage VFB1 by an adder CB, and inputted to a comparator CMP1. The ON period of a one-shot pulse PS1 outputted from the comparator CMP1 is regulated so as to be in direct proportion to the sum of the detection voltage VQD and the feedback voltage VFB1.
    Type: Application
    Filed: March 7, 2012
    Publication date: September 13, 2012
    Applicant: Rohm Co., Ltd.
    Inventor: Kazuhiro Murakami
  • Patent number: 8232197
    Abstract: An insulating film formed on a conducting layer is dry-etched so as to make a connection hole in the insulating film to expose the conducting layer. Plasma is supplied onto the exposed conducting layer to dry-clean a damage layer produced in the connection hole. A product produced in the connection hole as a result of the dry cleaning is removed by a wet process. An oxide film formed in the connection hole as a result of the wet process is etched by a chemical dry process using a gas including either NF3 or HF. A thermally decomposable reaction product produced as a result of the etching is removed by heat treatment.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: July 31, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Makoto Honda, Kaori Yomogihara, Kazuhiro Murakami, Masanori Numano, Takahito Nagamatsu, Hideaki Harakawa, Hideto Matsuyama, Hirokazu Ezawa, Hisashi Kaneko
  • Publication number: 20120127151
    Abstract: The power supply device according to the present invention comprises a first power supply circuit arranged to generate a first output voltage from an input voltage; and a second power supply circuit arranged to generate from the input voltage a second output voltage that is less than the first output voltage, wherein the first power supply circuit performs feedback control of the first output voltage so as to cause a first feedback voltage that corresponds to the first output voltage to match a predetermined reference voltage; and the second power supply circuit performs feedback control of the second output voltage so as to cause a second feedback voltage that corresponds to the second output voltage to match the first feedback voltage.
    Type: Application
    Filed: November 17, 2011
    Publication date: May 24, 2012
    Applicant: ROHM CO., LTD.
    Inventor: Kazuhiro Murakami
  • Publication number: 20120049829
    Abstract: A power supply apparatus A according to the present invention comprises a drive control circuit for generating an on/off control signal of an output transistor; an overcurrent protection circuit for directly or indirectly monitoring a coil current and generating an overcurrent detection signal; and a soft-start control circuit for suppressing a rise in an output voltage by using a soft-start voltage for starting an increase slowly after startup of the power supply apparatus, wherein, when the coil current is in an overcurrent state, the drive control circuit repeats a forced reset operation of the on/off control signal in accordance with the overcurrent detection signal, and a set operation of the on/off control signal in accordance with a clock signal of a predetermined frequency, as a pulse-by-pulse overcurrent protection operation; and the soft-start control circuit gradually reduces the soft-start voltage as a reset operation in accordance with the overcurrent detection signal.
    Type: Application
    Filed: May 18, 2010
    Publication date: March 1, 2012
    Applicant: ROHM CO., LTD.
    Inventor: Kazuhiro Murakami
  • Publication number: 20120006794
    Abstract: [Problem] To provide a metal connecting method and a metal connecting device to prevent a shot-circuit between the core wire and the shield portion by preventing the insulating inner coat from melting, and to surely connect the shield portion and the conductive member to each other. [Means for solving problem] The ground terminal 4 is wound around an outer periphery of the coaxial cable 3. A portion of the ground terminal 4 wound around the coaxial cable 3 is clipped between the pair of electrodes 11, 12. While the pair of electrodes 11, 12 is pressed in a direction close to each other, a current is applied to the pair of electrodes 11, 12. The current of a predetermined current value is applied for a predetermined time so that the insulating outer coat 34 is heated more than the melting point of the insulating outer coat 34, the braided wire 33 and the ground terminal 4 are connected to each other, and the insulating inner coat 32 is heated less than the melting point of the insulating inner coat 32.
    Type: Application
    Filed: March 9, 2010
    Publication date: January 12, 2012
    Applicant: Yazaki Corporation
    Inventors: Kazuhiro Murakami, Yoshihiko Watanabe
  • Publication number: 20110318598
    Abstract: In a first metal plate 10 in which a first hole 16 is formed, a second metal plate 12 in which a second hole 18 is formed and a third metal plate 11 which is sandwiched between the first metal plate 10 and the second plate 12 and in which a third hole 17 is formed, a first protruding portion 13 is provided integrally with the first metal plate 10, and a second protruding portion 14 is provided integrally with the third metal plate 11. The first protruding portion 13 extends from part of an end face of the first metal plate 10 which defines the first hole 16 and is bent towards the third metal plate 11 so as to fit into the third hole 17. The second protruding portion 14 extends from part of an end face of the third metal plate 11 which defines the third hole 17 and is bent towards the second metal plate 12 so as to fit into the second hole 18.
    Type: Application
    Filed: March 10, 2010
    Publication date: December 29, 2011
    Applicant: YAZAKI CORPORATION
    Inventors: Kazuhiro Murakami, Yoshihiko Watanabe, Kazuhide Takahashi, Kimitoshi Makino