Patents by Inventor Takashi Sase
Takashi Sase 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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Publication number: 20070262761Abstract: In a switching power supply apparatus for performing a switching control of a power MOS transistor that flows current to a coil and converting input voltage into output voltage, even if there occurs offset voltage in a current sensing operational amplifier, source potential of a current sensing MOS transistor is precisely kept at source potential of a low side power MOS transistor. For example, an offset cancel capacitor is arranged at an inverting input terminal of the current sensing operational amplifier, and voltage in the direction to offset the offset voltage occurring in the operational amplifier is charged to this capacitor.Type: ApplicationFiled: January 10, 2007Publication date: November 15, 2007Inventors: Takuya ISHIGAKI, Takashi Sase, Akihiko Kanouda, Koji Kateno, Ryotaro Kudo
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Patent number: 7268611Abstract: A semiconductor device capable of achieving downsizing without reducing the power supply efficiency and capable of reducing switching noises and a memory card using the same are disclosed. The device comprises a plurality of stages of voltage booster circuits for potentially raising a power supply voltage up to a final output voltage, a voltage control unit for controlling an output voltage at a nearby location of the final stage, and one or more internal elements to which the final output voltage is supplied. A primary voltage booster circuit at the first stage includes an inductance element, a switching element, a diode and a driver circuit. At a metal core part of the inductance element, a metal wiring line is used, which was formed by use of a fabrication process of semiconductor integrated circuits, while employing for its core part an inter-wiring layer dielectric film that was formed using the fabrication process.Type: GrantFiled: August 8, 2003Date of Patent: September 11, 2007Assignee: Renesas Technology CorporationInventors: Mutsumi Kikuchi, Noboru Akiyama, Hiroyuki Shoji, Fumio Murabayashi, Akihiko Kanouda, Takashi Sase, Koji Tateno
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Publication number: 20070188958Abstract: An over-current detection circuit using the ON-voltage of a main MOSFET is provided, which is resistant to process variations of a main MOSFET and is not easily influenced by switching noise. Separately from a main MOSFET (Q1), a sense MOSFET (Q3) whose size is 1/m of the main MOSFET is provided and it is caused to be normally on. A DC ON-voltage generated when a current that is 1/m of an over-current value is caused to flow through the sense MOSFET is obtained as a reference voltage for over-current setting. The ON-voltage when the main MOSFET is on is sampled and held, and it is obtained as a DC voltage. These DC voltages are compared in a comparator (COMP).Type: ApplicationFiled: August 18, 2006Publication date: August 16, 2007Applicant: Hitachi, Ltd.Inventors: Takashi Sase, Akihiko Kanouda, Yosuke Kawakubo, Kozaburo Kurita
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Publication number: 20070120540Abstract: A power-supply device comprising such marginal check voltage setting circuit that is easily adaptable to downsizing of the device and to configuration using ICs. The power-supply device of this invention comprises a marginal check voltage setting circuit that accepts input of a reference voltage and sets a desired marginal check voltage, an error amplifier that accepts input of the marginal check voltage and also the output voltage of the power-supply device and delivers output of an error signal, that is, the difference between the two inputs, a pulse width modulation oscillator that modulates the pulse width of the output from the error amplifier, a driver circuit that generates driving signal from the pulse signal originating from the pulse width modulation oscillator, and a pair of power semiconductor switching devices that work to step down the input voltage and generate an output voltage based on the driving signal.Type: ApplicationFiled: December 30, 2005Publication date: May 31, 2007Inventors: Takashi Sase, Akihiko Kanouda, Yosuke Kawakubo
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Patent number: 7170273Abstract: The object of the invention is to compensate an effect of a voltage drop emerging in output voltage by the equivalent series resistance of a power output filter in a power-supply device. To achieve the object, a power-supply device wherein the power output filter that passes output power and first and second filters provided separately from the power output filter are provided, the first filter provided separately and one input terminal of an error amplifier are connected, new reference voltage acquired by adding differential voltage between the output of the second filter provided separately and the output of the power output filter to reference voltage is input to the other input terminal of the error amplifier and an output signal is fed back to the error amplifier is provided. According to the power-supply device, a voltage drop by equivalent series resistance emerging the output voltage of the power-supply device can be compensated.Type: GrantFiled: August 6, 2004Date of Patent: January 30, 2007Assignee: Hitachi, Ltd.Inventors: Takashi Sase, Akihiko Kanouda, Katsunori Hayashi
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Patent number: 7138786Abstract: A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.Type: GrantFiled: November 28, 2005Date of Patent: November 21, 2006Assignee: Renesas Technology Corp.Inventors: Takuya Ishigaki, Takashi Sase, Akihiko Kanouda, Koji Tateno, Ryotaro Kudo
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Patent number: 7109693Abstract: There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.Type: GrantFiled: March 21, 2006Date of Patent: September 19, 2006Assignee: Renesas Technology Corp.Inventors: Shinichi Yoshida, Tomohiro Tazawa, Takashi Sase, Kouji Tateno
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Patent number: 7102388Abstract: A first converter circuit converts a state signal, whose level is constant or slowly varies during a predetermine period of time, into a pulse signal to allow the signal to propagate across an electrically insulating area. A second converter circuit converts the pulse signal, which has propagated through an insulating circuit, into the original state signal or a signal having the same characteristics as the original state signal.Type: GrantFiled: February 4, 2003Date of Patent: September 5, 2006Assignee: Hitachi, Ltd.Inventors: Fumio Murabayashi, Takashi Sase, Mutsumi Kikuchi, Atsuo Watanabe, Masatsugu Amishiro, Kenji Tabuchi
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Patent number: 7091711Abstract: There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.Type: GrantFiled: December 16, 2005Date of Patent: August 15, 2006Assignee: Renesas Technology Corp.Inventors: Shinichi Yoshida, Tomohiro Tazawa, Takashi Sase, Kouji Tateno
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Patent number: 7088594Abstract: A resonant converter which can realize its easy design, eliminate the need for its adjustment, realize reliable soft switching operation, and increase an efficiency. A driver DRV of a main switching device uses a PLL circuit PLL to apply frequency tracking control in such a manner that a driving frequency fsw is made to track a resonant frequency fr (or 1/N thereof, N being an odd number) and that the phase of the driving frequency fsw leads the current zero phase of the resonant frequency fr always by a desired time. As a result, such an optimum condition can be kept that the main switching device is triggered immediately before the zero-cross point of a resonant current. Thus the resonant converter which can always satisfy the optimum operational conditions, realize soft switching operation, and increase an efficiency can be realized with an easy design and a manufacturing adjustment-free arrangement.Type: GrantFiled: November 10, 2004Date of Patent: August 8, 2006Assignee: Hitachi, Ltd.Inventors: Takashi Sase, Akihiko Kanouda, Tetsuya Nagayama, Tadahiko Hashimoto
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Publication number: 20060158168Abstract: There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.Type: ApplicationFiled: March 21, 2006Publication date: July 20, 2006Inventors: Shinichi Yoshida, Tomohiro Tazawa, Takashi Sase, Kouji Tateno
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Publication number: 20060113979Abstract: A power supply driver circuit with low power losses and desired response characteristics with respect to changes in output and its miniaturization is provided. In a driver IC constituting a switched-mode power supply equipment controlling the switching, by pulse width modulation, of first and second power transistors passing a current in a coil, and outputting a voltage bucked or boosted from an input voltage, current sensing with desired responsiveness is enabled by providing a switching transistor between an inverted input terminal and a non-inverted input terminal of an operational amplifier, preventing, while the second power transistor is ON, the generation of a potential which is undefined when first power transistor is ON, i.e. when the second power transistor is OFF, and maintaining a node potential in a state in which the potential is well defined.Type: ApplicationFiled: November 28, 2005Publication date: June 1, 2006Inventors: Takuya Ishigaki, Takashi Sase, Akihiko Kanouda, Koji Tateno, Ryotaro Kudo
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Publication number: 20060091870Abstract: There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.Type: ApplicationFiled: December 16, 2005Publication date: May 4, 2006Inventors: Shinichi Yoshida, Tomohiro Tazawa, Takashi Sase, Kouji Tateno
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Patent number: 6979985Abstract: There is provided a switching power supply device of hysteresis current mode control system which assures excellent response characteristic for change of output current and reduction of power consumption. In a switching regulator of hysteresis current mode control system, a sense resistor connected in series to a coil is eliminated, a serially connected resistor and a capacitor are connected in parallel to a coil in place of such sense resistor. Thereby, a potential of a connection node of these resistor and capacitor is inputted to a comparator circuit having the hysteresis characteristic for comparison with the reference voltage. Accordingly, a switch may be controlled for ON and OFF states.Type: GrantFiled: June 3, 2003Date of Patent: December 27, 2005Assignee: Renesas Technology Corp.Inventors: Shinichi Yoshida, Tomohiro Tazawa, Takashi Sase, Kouji Tateno
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Patent number: 6977522Abstract: A first converter circuit converts a state signal, whose level is constant or slowly varies during a predetermine period of time, into a pulse signal to allow the signal to propagate across an electrically insulating area. A second converter circuit converts the pulse signal, which has propagated through an insulating circuit, into the original state signal or a signal having the same characteristics as the original state signal.Type: GrantFiled: December 15, 1999Date of Patent: December 20, 2005Assignee: Hitachi, Ltd.Inventors: Fumio Murabayashi, Takashi Sase, Mutsumi Kikuchi, Atsuo Watanabe, Masatsugu Amishiro, Kenji Tabuchi
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Publication number: 20050237039Abstract: A semiconductor device capable of achieving downsizing without reducing the power supply efficiency and capable of reducing switching noises and a memory card using the same are disclosed. The device comprises a plurality of stages of voltage booster circuits for potentially raising a power supply voltage up to a final output voltage, a voltage control unit for controlling an output voltage at a nearby location of the final stage, and one or more internal elements to which the final output voltage is supplied. A primary voltage booster circuit at the first stage includes an inductance element, a switching element, a diode and a driver circuit. At a metal core part of the inductance element, a metal wiring line is used, which was formed by use of a fabrication process of semiconductor integrated circuits, while employing for its core part an inter-wiring layer dielectric film that was formed using the fabrication process.Type: ApplicationFiled: August 8, 2003Publication date: October 27, 2005Inventors: Mutsumi Kikuchi, Noboru Akiyama, Hiroyuki Shoji, Fumio Murabayashi, Akihiko Kanouda, Takashi Sase, Koji Tateno
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Patent number: 6947514Abstract: A phase locked loop (PLL) circuit is provided to operate in a broad band, including two separate loops one of which is for feed-back of an output from an oscillator to the same oscillator through its associative proportional control unit and the other of which is for feed-back of an output of an oscillator to the same oscillator via an integral control unit. The proportional control unit is arranged to control an output frequency of the oscillator and is operable to generate a control signal based on a difference between input and output signals. The integral control unit is arranged to control the phase of an output signal of the oscillator to thereby generate a control signal based on a phase difference between input and output signals.Type: GrantFiled: June 26, 1998Date of Patent: September 20, 2005Assignee: Renesas Technology CorporationInventors: Kazuo Kato, Takashi Sase, Takashi Hotta, Hirokazu Aoki, Kozaburo Kurita
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Publication number: 20050127886Abstract: A step-down type DC-DC power supply device implements both the stabilization of the control loop and the responsibility at the same time. In the power-supply device, an output power signal is fed back to an error amplifier after having passed through a CR smoothing filter provided independently of a power LC smoothing filter. Also, independently of the duty controls over Power MOSFETs, i.e., upper-side/lower-side semiconductor switching components in the steady state, an output from the power LC smoothing filter is added to an upper and lower limit-mode-equipped control circuit, thereby, at the transient state, forcefully setting the duty ? at either 0% or 100%.Type: ApplicationFiled: January 27, 2005Publication date: June 16, 2005Inventors: Takashi Sase, Koji Tateno, Akihiko Kanouda, Katsunori Hayashi, Shinichi Yoshida
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Publication number: 20050127881Abstract: The object of the invention is to compensate an effect of a voltage drop emerging in output voltage by the equivalent series resistance of a power output filter in a power-supply device. To achieve the object, a power-supply device wherein the power output filter that passes output power and first and second filters provided separately from the power output filter are provided, the first filter provided separately and one input terminal of an error amplifier are connected, new reference voltage acquired by adding differential voltage between the output of the second filter provided separately and the output of the power output filter to reference voltage is input to the other input terminal of the error amplifier and an output signal is fed back to the error amplifier is provided. According to the power-supply device, a voltage drop by equivalent series resistance emerging the output voltage of the power-supply device can be compensated.Type: ApplicationFiled: August 6, 2004Publication date: June 16, 2005Inventors: Takashi Sase, Akihiko Kanouda, Katsunori Hayashi
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Publication number: 20050099827Abstract: A resonant converter which can realize its easy design, eliminate the need for its adjustment, realize reliable soft switching operation, and increase an efficiency. A driver DRV of a main switching device uses a PLL circuit PLL to apply frequency tracking control in such a manner that a driving frequency fsw is made to track a resonant frequency fr (or 1/N thereof, N being an odd number) and that the phase of the driving frequency fsw leads the current zero phase of the resonant frequency fr always by a desired time. As a result, such an optimum condition can be kept that the main switching device is triggered immediately before the zero-cross point of a resonant current. Thus the resonant converter which can always satisfy the optimum operational conditions, realize soft switching operation, and increase an efficiency can be realized with an easy design and a manufacturing adjustment-free arrangement.Type: ApplicationFiled: November 10, 2004Publication date: May 12, 2005Applicant: HITACHI LTD.Inventors: Takashi Sase, Akihiko Kanouda, Tetsuya Nagayama, Tadahiko Hashimoto