Patents by Inventor Takayoshi Nishiyama

Takayoshi Nishiyama 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: 10530244
    Abstract: A switch circuit includes a first switch element defined by an FET, and an active snubber circuit connected between a drain and a source of the first switch element and including a second switch element defined by an FET, a capacitor connected in series to the second switch element, a third switch element connected to a gate of the second switch element and turned on to extract an electric charge of capacitance between the gate and a source of the second switch element, and a delay circuit that turns on the third switch element at a timing delayed from a timing at which the second switch element is turned on.
    Type: Grant
    Filed: October 3, 2018
    Date of Patent: January 7, 2020
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Takami Muto, Takayoshi Nishiyama
  • Patent number: 10497631
    Abstract: An insulated DC-DC converter includes a substrate, a transformer, a primary side electronic component and a primary side wire defining a primary side circuit together with a primary winding, a secondary side electronic component and a secondary side wire defining a secondary side circuit insulated from the primary side circuit, together with a secondary winding, the secondary side electronic component including a choke coil, and an inter-circuit electronic component and an inter-primary side circuit wire connected over the primary side circuit and the secondary side circuit while insulating the primary side circuit and the secondary side circuit from each other in a DC manner.
    Type: Grant
    Filed: January 22, 2018
    Date of Patent: December 3, 2019
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Takami Muto, Takayuki Yamamoto, Takayoshi Nishiyama, Naoto Kinoshita, Yuki Abura, Yoshihiro Matsumoto
  • Patent number: 10348213
    Abstract: A DC-DC converter includes a voltage input portion that receives a DC voltage, a voltage output portion to which a load is connected, a transformer that includes at least a primary winding and a secondary winding, a main switch element between the voltage input portion and the primary winding of the transformer, a rectifier circuit between the voltage output portion and the secondary winding of the transformer, and a reset voltage suppressing circuit that detects a magnitude of a reset voltage generated when excitation energy accumulated in the transformer is reset and reduces a voltage which is applied to the main switch element when the magnitude of the reset voltage exceeds, for example, a predetermined threshold value.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: July 9, 2019
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventors: Takami Muto, Takayoshi Nishiyama
  • Publication number: 20190044450
    Abstract: A DC-DC converter includes a voltage input portion that receives a DC voltage, a voltage output portion to which a load is connected, a transformer that includes at least a primary winding and a secondary winding, a main switch element between the voltage input portion and the primary winding of the transformer, a rectifier circuit between the voltage output portion and the secondary winding of the transformer, and a reset voltage suppressing circuit that detects a magnitude of a reset voltage generated when excitation energy accumulated in the transformer is reset and reduces a voltage which is applied to the main switch element when the magnitude of the reset voltage exceeds, for example, a predetermined threshold value.
    Type: Application
    Filed: October 2, 2018
    Publication date: February 7, 2019
    Inventors: Takami MUTO, Takayoshi NISHIYAMA
  • Publication number: 20190036445
    Abstract: A switch circuit includes a first switch element defined by an FET, and an active snubber circuit connected between a drain and a source of the first switch element and including a second switch element defined by an FET, a capacitor connected in series to the second switch element, a third switch element connected to a gate of the second switch element and turned on to extract an electric charge of capacitance between the gate and a source of the second switch element, and a delay circuit that turns on the third switch element at a timing delayed from a timing at which the second switch element is turned on.
    Type: Application
    Filed: October 3, 2018
    Publication date: January 31, 2019
    Inventors: Takami MUTO, Takayoshi NISHIYAMA
  • Publication number: 20180145598
    Abstract: An insulated DC-DC converter includes a substrate, a transformer, a primary side electronic component and a primary side wire defining a primary side circuit together with a primary winding, a secondary side electronic component and a secondary side wire defining a secondary side circuit insulated from the primary side circuit, together with a secondary winding, the secondary side electronic component including a choke coil, and an inter-circuit electronic component and an inter-primary side circuit wire connected over the primary side circuit and the secondary side circuit while insulating the primary side circuit and the secondary side circuit from each other in a DC manner.
    Type: Application
    Filed: January 22, 2018
    Publication date: May 24, 2018
    Inventors: Takami MUTO, Takayuki YAMAMOTO, Takayoshi NISHIYAMA, Naoto KINOSHITA, Yuki ABURA, Yoshihiro MATSUMOTO
  • Patent number: 9385586
    Abstract: A snubber circuit of a switching power supply device includes a transistor and a capacitor which are connected in series between a cathode and an anode of a diode, and a secondary winding of a transformer. A vibration voltage is generated in the secondary winding when a surge voltage is generated in the diode. The snubber circuit further includes a differentiating circuit which differentiates a voltage between terminals of the secondary winding, and a peak charging circuit which generates a control voltage of a waveform connecting a plurality of peaks of an output voltage of the differentiating circuit and applies the control voltage to a gate of the transistor to cause the transistor conduct.
    Type: Grant
    Filed: January 21, 2014
    Date of Patent: July 5, 2016
    Assignee: MURATA MANUFACTURING CO., LTD.
    Inventor: Takayoshi Nishiyama
  • Publication number: 20140133188
    Abstract: A snubber circuit of a switching power supply device includes a transistor and a capacitor which are connected in series between a cathode and an anode of a diode, and a secondary winding of a transformer. A vibration voltage is generated in the secondary winding when a surge voltage is generated in the diode. The snubber circuit further includes a differentiating circuit which differentiates a voltage between terminals of the secondary winding, and a peak charging circuit which generates a control voltage of a waveform connecting a plurality of peaks of an output voltage of the differentiating circuit and applies the control voltage to a gate of the transistor to cause the transistor conduct.
    Type: Application
    Filed: January 21, 2014
    Publication date: May 15, 2014
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventor: Takayoshi NISHIYAMA
  • Publication number: 20130301312
    Abstract: An isolated switching power supply apparatus includes a transformer, a primary-side circuit that includes at least a switching element and supplies input power from an input terminal to a primary winding by controlling on/off of the switching element, and a secondary-side circuit that is electrically isolated from the primary-side circuit and that outputs output power resulting from power conversion performed by the transformer from a secondary winding to an output terminal. The apparatus includes a first circuit board to which the primary winding is connected and that includes the primary-side circuit and the input terminal, and a second circuit board to which the secondary winding is connected and that includes the secondary-side circuit and the output terminal. The first and second circuit boards are stacked in a multilayer manner. The primary and secondary windings are arranged around a core that extends through the first and second circuit boards.
    Type: Application
    Filed: July 19, 2013
    Publication date: November 14, 2013
    Inventors: Masanori KONISHI, Takayoshi NISHIYAMA
  • Patent number: 7868584
    Abstract: A DC-DC converter includes an inductor, a capacitor, an output voltage detection circuit, and a synchronous rectification circuit including a rectifier-side synchronous rectifier element and a commutator-side synchronous rectifier element. The commutator-side synchronous rectifier element is turned on so as to pass a current through a closed loop composed of the commutator-side synchronous rectifier element, the inductor, and a second secondary battery. The characteristic evaluation of the second secondary battery is performed on the basis of the decrease in a detection voltage Vout of an output voltage Vo. As a result, it is possible to determine the effective capacity or characteristic degradation state of the second secondary battery with a circuit to charge the second secondary battery without using a dedicated circuit.
    Type: Grant
    Filed: July 20, 2010
    Date of Patent: January 11, 2011
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takashi Hara, Takayoshi Nishiyama, Koichi Ueki
  • Patent number: 7852647
    Abstract: A switching power supply apparatus includes a transformer or an inductor, a switching element connected to the transformer or the inductor and configured to perform switching of an input power supply, and a switching control circuit including a digital control circuit configured to sample voltage values and/or current values and control on and off of the switching element in accordance with the voltage values and/or current values. The number of points of sampling is set to n or more points, where n is an integer greater than 3, in an ON period of the switching element except at around a turn-on point or a turn-off point of the switching element. The presence or absence of magnetic saturation of the transformer or the inductor is detected on the basis of whether or not a slope of change in current value over time is larger than a predetermined value, and circuit operation is protected from the effect of magnetic saturation.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: December 14, 2010
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takayoshi Nishiyama, Takashi Hara, Koichi Ueki
  • Publication number: 20100277132
    Abstract: A DC-DC converter includes an inductor, a capacitor, an output voltage detection circuit, and a synchronous rectification circuit including a rectifier-side synchronous rectifier element and a commutator-side synchronous rectifier element. The commutator-side synchronous rectifier element is turned on so as to pass a current through a closed loop composed of the commutator-side synchronous rectifier element, the inductor, and a second secondary battery. The characteristic evaluation of the second secondary battery is performed on the basis of the decrease in a detection voltage Vout of an output voltage Vo. As a result, it is possible to determine the effective capacity or characteristic degradation state of the second secondary battery with a circuit to charge the second secondary battery without using a dedicated circuit.
    Type: Application
    Filed: July 20, 2010
    Publication date: November 4, 2010
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Takashi HARA, Takayoshi NISHIYAMA, Koichi UEKI
  • Patent number: 7821797
    Abstract: A switching circuit arranged to switch the input of an input power supply is connected to a primary winding of a transformer at a primary side of the transformer. A digital control circuit including a switching controller arranged to output control pulses to the switching circuit and a rectifying/smoothing circuit connected to secondary windings of the transformer are disposed at a secondary side of the transformer. The digital control circuit outputs the control pulses via a pulse transformer, calculates the input power-supply voltage on the basis of the on-duty cycle of the control pulses, the output voltage, and the ratio of the number of turns of the primary winding to the number of turns of the secondary windings of the transformer, and performs converter control in accordance with the calculated input power-supply voltage.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: October 26, 2010
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takayoshi Nishiyama, Koichi Ueki
  • Publication number: 20100195353
    Abstract: A switching power supply apparatus includes a transformer or an inductor, a switching element connected to the transformer or the inductor and configured to perform switching of an input power supply, and a switching control circuit including a digital control circuit configured to sample voltage values and/or current values and control on and off of the switching element in accordance with the voltage values and/or current values. The number of points of sampling is set to n or more points, where n is an integer greater than 3, in an ON period of the switching element except at around a turn-on point or a turn-off point of the switching element. The presence or absence of magnetic saturation of the transformer or the inductor is detected on the basis of whether or not a slope of change in current value over time is larger than a predetermined value, and circuit operation is protected from the effect of magnetic saturation.
    Type: Application
    Filed: April 15, 2010
    Publication date: August 5, 2010
    Applicant: MURATA MANUFACTURING CO., LTD.
    Inventors: Takayoshi NISHIYAMA, Takashi HARA, Koichi UEKI
  • Publication number: 20100103703
    Abstract: A switching circuit arranged to switch the input of an input power supply is connected to a primary winding of a transformer at a primary side of the transformer. A digital control circuit including a switching controller arranged to output control pulses to the switching circuit and a rectifying/smoothing circuit connected to secondary windings of the transformer are disposed at a secondary side of the transformer. The digital control circuit outputs the control pulses via a pulse transformer, calculates the input power-supply voltage on the basis of the on-duty cycle of the control pulses, the output voltage, and the ratio of the number of turns of the primary winding to the number of turns of the secondary windings of the transformer, and performs converter control in accordance with the calculated input power-supply voltage.
    Type: Application
    Filed: January 15, 2010
    Publication date: April 29, 2010
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Takayoshi NISHIYAMA, Koichi UEKI
  • Publication number: 20080170418
    Abstract: A DC-DC converter includes a resonant coil (Lr) for zero voltage switching, the resonant coil being connected in series to a primary winding (Np), and a full-bridge switching circuit driven by phase shift control. The DC-DC converter includes a first regenerative diode (D7) disposed between a connection between the primary winding (Np) and the resonant coil (Lr) and a first terminal of an input power supply (Vin) and a second regenerative diode (D8) disposed between the connection and a second terminal of the input power supply (Vin). This structure enables a surge resulting from a reverse recovery current in rectifier diodes (D1, D2) at the secondary side to be regenerated to the input power supply via the regenerative diodes (D7, D8), thus reducing a surge voltage applied to the rectifier diodes (D1, D2). As a result, a rectifier diode that has a low breakdown voltage and a small forward voltage drop can be used. The loss caused by a forward current in the rectifier diodes can be reduced.
    Type: Application
    Filed: December 20, 2007
    Publication date: July 17, 2008
    Inventors: Takayoshi Nishiyama, Hiroshi Takemura, Koichi Ueki
  • Patent number: 7158394
    Abstract: A switching power supply circuit reduces the time from start-up driving to normal operation while a soft-start is carried out with an output voltage Vout. A soft-start capacitor is charged during the start-up time. After a soft-start voltage Vz has reached a predetermined signal-output starting voltage Vlow, soft start of the output voltage Vout is carried out by controlling the operation based on the soft-start voltage Vz. A time constant for charging the soft-start capacitor is set as a time constant that causes the charge voltage of the soft-start capacitor to sharply increase at least until the soft-start voltage Vz reaches the signal-output starting voltage Vlow after the circuit has started driving, and is switched to a time constant that causes a rising trend of the charge voltage of the soft-start capacitor to become gentle with a predetermined time-constant switching timing.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: January 2, 2007
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Seiichi Takahashi, Takayoshi Nishiyama, Jun Nagai, Eito Moromizato
  • Publication number: 20060164871
    Abstract: A switching power supply circuit reduces the time from start-up driving to normal operation while a soft-start is carried out with an output voltage Vout. A soft-start capacitor is charged during the start-up time. After a soft-start voltage Vz has reached a predetermined signal-output starting voltage Vlow, soft start of the output voltage Vout is carried out by controlling the operation based on the soft-start voltage Vz. A time constant for charging the soft-start capacitor is set as a time constant that causes the charge voltage of the soft-start capacitor to sharply increase at least until the soft-start voltage Vz reaches the signal-output starting voltage Vlow after the circuit has started driving, and is switched to a time constant that causes a rising trend of the charge voltage of the soft-start capacitor to become gentle with a predetermined time-constant switching timing.
    Type: Application
    Filed: February 10, 2005
    Publication date: July 27, 2006
    Inventors: Seiichi Takahashi, Takayoshi Nishiyama, Jun Nagai, Eito Moromizato
  • Patent number: 6876555
    Abstract: A transformer of a switching power-supply circuit is placed and mounted nearly in the middle area of a circuit board. The transformer is of a low-profile type, and a broad and flat upper surface of the transformer functions as a suction surface for a suction nozzle. When a surface-mount type switching power-supply unit is mounted in a mother board, firstly, the upper surface of the above transformer is held by the suction nozzle, the surface-mount type switching power-supply unit is transferred to a target mounting area on the mother board by the suction nozzle, and the surface-mount type switching power-supply unit is surface mounted in the mother board. Because it is not required to provide a nozzle suction surface for the suction nozzle's exclusive use, transfer molding is not needed, and accordingly a low-profile and low-cost surface-mount type switching power-supply unit can be facilitated.
    Type: Grant
    Filed: August 1, 2002
    Date of Patent: April 5, 2005
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tadehiko Matsumoto, Takayoshi Nishiyama, Jun Nagai
  • Patent number: 6757174
    Abstract: A switching power-supply module includes a coil pattern of a transformer or an inductor disposed on a substrate. A portion of the coil pattern projects into an edge portion of the substrate. A plurality of terminals are arranged in the substrate edge portion so that they do not touch the coil pattern. The substrate edge portion is soaked in molten solder in the production procedure in order to fix the terminals onto the substrate with solder after components are solder-connected on the substrate. For this reason, the components were previously prohibited from being mounted in the substrate edge portion, and this region has been previously considered to be a dead space. However, in the present invention, since a portion of the coil pattern projects into the substrate edge portion, dead space is minimized, and the size of the substrate, that is, of the switching power supply module is greatly reduced.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: June 29, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Jun Nagai, Yoshihiro Matsumoto, Takayoshi Nishiyama, Tadahiko Matsumoto