Patents by Inventor Toshio Nagasawa

Toshio Nagasawa 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: 20090015220
    Abstract: A switching power supply device performs a stable operation with fast response for a semiconductor integrated circuit device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction.
    Type: Application
    Filed: July 10, 2008
    Publication date: January 15, 2009
    Inventors: Toshio Nagasawa, Ryotaro Kudo
  • Patent number: 7436070
    Abstract: A non-insulated DC-DC converter hs a power MOS•FRT for a highside switch and a power MOS•FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•FET for the highside switch and the power MOS•FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: October 14, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
  • Patent number: 7408388
    Abstract: There are provided a switching power supply device performing a stable operation with fast response, a semiconductor integrated circuit device, and a power supply device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction. The number of cells is 1/N. A detection MOSFET in which the gains and the drains are shared over the same semiconductor substrate with the first power MOSFET is provided to form a second feedback signal.
    Type: Grant
    Filed: October 26, 2006
    Date of Patent: August 5, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Toshio Nagasawa, Ryotaro Kudo
  • Publication number: 20080129273
    Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.
    Type: Application
    Filed: January 22, 2008
    Publication date: June 5, 2008
    Inventors: Koji TATENO, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
  • Patent number: 7345340
    Abstract: A semiconductor integrated circuit that has a quick response to changes in source/drain electrode voltage having an LDMOS transistor. The transistor has a second conduction type first well region formed in a first conduction type semiconductor substrate; a first conduction type second well region formed in the first well region; a second conduction type third well region formed in the second well region; a drain region formed in the second well region; a source region formed in the third well region; a gate electrode formed through a gate insulating film over the third well region between the drain region and the source region; and an insulating layer formed between the gate electrode and the drain region. Parasitic capacitances between the semiconductor substrate and the source region and those between the substrate and the drain region are respectively in series.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: March 18, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Mitsuharu Hitani, Toshio Nagasawa, Akihiro Tamura
  • Patent number: 7342391
    Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: March 11, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
  • Publication number: 20070236204
    Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor, and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.
    Type: Application
    Filed: June 8, 2007
    Publication date: October 11, 2007
    Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
  • Patent number: 7245116
    Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: July 17, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
  • Publication number: 20070159150
    Abstract: The present invention provides a switching power source and a semiconductor integrated circuit which realize an acquisition a sufficient driving voltage of a high-potential side switching element M1 even when a power source voltage VDD is low.
    Type: Application
    Filed: January 14, 2005
    Publication date: July 12, 2007
    Inventors: Kyoichi Hosokawa, Ryotaro Kudo, Toshio Nagasawa, Koji Tateno
  • Publication number: 20070103005
    Abstract: There are provided a switching power supply device performing a stable operation with fast response, a semiconductor integrated circuit device, and a power supply device. A capacitor is provided between the output side of an inductor and a ground potential. A first power MOSFET supplies an electric current from an input voltage to the input side of the inductor. A second power MOSFET turned on when the first power MOSFET is off allows the input side of the inductor to be of a predetermined potential. A first feedback signal corresponding to an output voltage obtained from the output side of the inductor and a second feedback signal corresponding to an electric current flowed to the first power MOSFET are used to form a PWM signal. The first power MOSFET has plural cells of a vertical type MOS-construction. The number of cells is 1/N. A detection MOSFET in which the gains and the drains are shared over the same semiconductor substrate with the first power MOSFET is provided to form a second feedback signal.
    Type: Application
    Filed: October 26, 2006
    Publication date: May 10, 2007
    Inventors: Toshio Nagasawa, Ryotaro Kudo
  • Publication number: 20060086973
    Abstract: A semiconductor integrated circuit that has a quick response to changes in source/drain electrode voltage having an LDMOS transistor. The transistor has a second conduction type first well region formed in a first conduction type semiconductor substrate; a first conduction type second well region formed in the first well region; a second conduction type third well region formed in the second well region; a drain region formed in the second well region; a source region formed in the third well region; a gate electrode formed through a gate insulating film over the third well region between the drain region and the source region; and an insulating layer formed between the gate electrode and the drain region. Parasitic capacitances between the semiconductor substrate and the source region and those between the substrate and the drain region are respectively in series.
    Type: Application
    Filed: October 20, 2005
    Publication date: April 27, 2006
    Inventors: Mitsuharu Hitani, Toshio Nagasawa, Akihiro Tamura
  • Publication number: 20050231177
    Abstract: In a driver circuit constructing a switching power supply device that switches power transistors passing a current through a coil by a PWM mode, a current detection transistor, which is smaller in size than the low-potential side power transistor and a current detection resistor are provided in parallel to the low-potential side power transistor. The same control voltage as the power transistor is applied to the control terminal of the current detection transistor. An operational amplifier is formed, that has the potential of the connection node between the current detection transistor and the current detection resistor applied to its inverse input terminal and a feedback loop, so as to make a pair of input terminals of the operational amplifier be at the same potential. A signal produced by the current detection resistor is thus outputted as a current detection signal.
    Type: Application
    Filed: April 7, 2005
    Publication date: October 20, 2005
    Inventors: Koji Tateno, Ryotaro Kudo, Shin Chiba, Kyoichi Hosokawa, Toshio Nagasawa
  • Publication number: 20050231990
    Abstract: A non-insulated DC-DC converter a power MOS·FRT for a highside switch and a power MOS·FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS·FET for the highside switch and the power MOS·FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS·FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.
    Type: Application
    Filed: April 19, 2005
    Publication date: October 20, 2005
    Inventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa
  • Patent number: 4518353
    Abstract: The disclosure relates to a vacuum sintering furnace having a lubricant eliminating section, sintering section and cooling section which are aligned in series and connected by connecting hood means to each other so that a workpiece may be directly transferred to the following section without exposure of the workpiece to outside air. The connecting hood means comprises doors for selectively opening and closing the boundaries between the neighboring sections. Furthermore, the lubricant eliminating section is provided with a lubricant trapping device mounted on an exhaust line connecting a furnace body and a vacuum pump to each other, thereby the stable operation of the vacuum pump is ensured.
    Type: Grant
    Filed: June 26, 1984
    Date of Patent: May 21, 1985
    Assignees: Chugai Ro Co., Ltd., Mitsubishi Kinzoku Kabushiki Kaisha
    Inventors: Takashi Banno, Tadashi Seki, Masafumi Kawaguchi, Yukio Tanaka, Morikatsu Iwasaki, Toshio Nagasawa
  • Patent number: 4412125
    Abstract: An electrical heating element material of a sheet form is provided, which is comprised of a web of a synthetic resin having a plurality of metal conductor wires arranged therein in parallel to one another along the longitudinal direction of the web. The web is folded in succession at predetermined intervals along folding lines inclined at a small acute angle to the transverse direction of the web to form a substantially two-layer parallelogrammatic sheet. Considering the small angle, the sheet is, for practical purposes, rectangular.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: October 25, 1983
    Assignee: Ube Industries, Ltd.
    Inventors: Toshio Nagasawa, Yoshio Nishihara
  • Patent number: 4370548
    Abstract: An electrical heating element material of a sheet form is provided, which is comprised of a web of a synthetic resin having a plurality of metal conductor wires arranged therein in parallel to one another along the longitudinal direction of the web. The web is folded in succession at predetermined intervals along folding lines inclined at a small acute angle to the transverse direction of the web to form a substantially two-layer parallelogrammatic sheet. Considering the small angle, the sheet is, for practical purposes, rectangular.
    Type: Grant
    Filed: August 11, 1980
    Date of Patent: January 25, 1983
    Assignee: Ube Industries, Ltd.
    Inventors: Toshio Nagasawa, Yoshio Nishihara
  • Patent number: 4323607
    Abstract: In a heat shrinkable synthetic resin cover adapted to seal a joint between two pipes or an electric cable, the cover is made of a rectangular sheet shaped cross-linked polymer and a flexible electric heater covered by a cross-linked polymer contained in a heat shrinkable synthetic resin member such that the electric heater crosses at right angles an inherent direction of heat shrink of the member so as not prevent inherent heat shrink thereof.
    Type: Grant
    Filed: August 23, 1979
    Date of Patent: April 6, 1982
    Assignees: UBE Industries, Ltd., The Furukawa Electric Co., Ltd.
    Inventors: Hiroshi Nishimura, Tetsuo Monma, Minoru Yoshida, Kazunari Kirimoto, Yoshio Hayamizu, Toshio Nagasawa
  • Patent number: 4078111
    Abstract: Provided hereinbelow is a process of extrusion-coating the central core, said core being used in a submarine coaxial cable, with an insulator of high pressure-processed polyethylene having a density of from 0.925 to 0.940 g/cm.sup.3 and a melt index of from 0.01 to 0.
    Type: Grant
    Filed: May 20, 1976
    Date of Patent: March 7, 1978
    Assignee: UBE Industries, Ltd.
    Inventors: Koji Yamaguchi, Hideaki Takashima, Iwao Tsurutani, Toshio Nagasawa