Patents by Inventor Tetsuyuki Fukushima

Tetsuyuki Fukushima 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: 10741545
    Abstract: A semiconductor device includes a first transistor and a second transistor. The first transistor includes a first body layer and a first connection part. The second transistor includes a second body layer and a second connection part. A second impedance, which is, in a path between the second connection part and the second body layer, inclusive, a maximum impedance seen by the first source electrode in the second body layer, is greater than a first impedance, which is, in a path between the first connection part and the first body layer, inclusive, a maximum impedance seen by the first source electrode in the first body layer.
    Type: Grant
    Filed: October 2, 2019
    Date of Patent: August 11, 2020
    Assignee: PANASONIC SEMICONDUCTOR SOLUTIONS CO., LTD.
    Inventors: Masaki Tamaru, Kazuma Yoshida, Michiya Otsuji, Tetsuyuki Fukushima
  • Publication number: 20200035669
    Abstract: A semiconductor device includes a first transistor and a second transistor. The first transistor includes a first body layer and a first connection part. The second transistor includes a second body layer and a second connection part. A second impedance, which is, in a path between the second connection part and the second body layer, inclusive, a maximum impedance seen by the first source electrode in the second body layer, is greater than a first impedance, which is, in a path between the first connection part and the first body layer, inclusive, a maximum impedance seen by the first source electrode in the first body layer.
    Type: Application
    Filed: October 2, 2019
    Publication date: January 30, 2020
    Inventors: Masaki TAMARU, Kazuma YOSHIDA, Michiya OTSUJI, Tetsuyuki FUKUSHIMA
  • Patent number: 10312339
    Abstract: In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.
    Type: Grant
    Filed: October 9, 2017
    Date of Patent: June 4, 2019
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Saichirou Kaneko, Hiroto Yamagiwa, Ayanori Ikoshi, Masayuki Kuroda, Manabu Yanagihara, Kenichiro Tanaka, Tetsuyuki Fukushima
  • Publication number: 20180040706
    Abstract: In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.
    Type: Application
    Filed: October 9, 2017
    Publication date: February 8, 2018
    Inventors: Saichirou KANEKO, Hiroto YAMAGIWA, Ayanori IKOSHI, Masayuki KURODA, Manabu YANAGIHARA, Kenichiro TANAKA, Tetsuyuki FUKUSHIMA
  • Patent number: 9818835
    Abstract: In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.
    Type: Grant
    Filed: August 11, 2016
    Date of Patent: November 14, 2017
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Saichirou Kaneko, Hiroto Yamagiwa, Ayanori Ikoshi, Masayuki Kuroda, Manabu Yanagihara, Kenichiro Tanaka, Tetsuyuki Fukushima
  • Publication number: 20160351676
    Abstract: In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.
    Type: Application
    Filed: August 11, 2016
    Publication date: December 1, 2016
    Inventors: Saichirou KANEKO, Hiroto YAMAGIWA, Ayanori IKOSHI, Masayuki KURODA, Manabu YANAGIHARA, Kenichiro TANAKA, Tetsuyuki FUKUSHIMA
  • Publication number: 20160035853
    Abstract: In a semiconductor device in the present disclosure, a first nitride semiconductor layer has a two-dimensional electron gas channel in a vicinity of an interface with a second nitride semiconductor layer. In plan view, an electrode portion is provided between a first electrode and a second electrode with a space between the first electrode and the second electrode, and a space between the second electrode and the electrode portion is smaller than the space between the first electrode and the electrode portion. An energy barrier is provided in a junction surface between the electrode portion and the second nitride semiconductor layer, the energy barrier indicating a rectifying action in a forward direction from the electrode portion to the second nitride semiconductor layer, and a bandgap of the second nitride semiconductor layer is wider than a bandgap of the first nitride semiconductor layer.
    Type: Application
    Filed: October 16, 2015
    Publication date: February 4, 2016
    Inventors: SAICHIROU KANEKO, HIROTO YAMAGIWA, AYANORI IKOSHI, MASAYUKI KURODA, MANABU YANAGIHARA, KENICHIRO TANAKA, TETSUYUKI FUKUSHIMA
  • Patent number: 9246402
    Abstract: A converter includes: a bridge diode; an X capacitor provided upstream of the bridge diode; a smoothing capacitor provided downstream of the bridge diode; an AC shutoff detection circuit which outputs an AC shutoff detection signal when input AC voltage is shut off; and a discharging circuit which is connected to a connection point at which the cathode of the bridge diode and the smoothing capacitor are connected, and allows residual charges in the smoothing capacitor and the X capacitor to be discharged when the AC shutoff detection signal is output, and the discharging circuit includes a JFET which has a drain terminal connected to the above connection point and lowers discharge voltage; and a first discharging switch element connected to the source terminal of the JFET.
    Type: Grant
    Filed: October 10, 2013
    Date of Patent: January 26, 2016
    Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
    Inventors: Tatsuya Sakurai, Takashi Saji, Tetsuyuki Fukushima
  • Publication number: 20140036561
    Abstract: A converter includes: a bridge diode; an X capacitor provided upstream of the bridge diode; a smoothing capacitor provided downstream of the bridge diode; an AC shutoff detection circuit which outputs an AC shutoff detection signal when input AC voltage is shut off; and a discharging circuit which is connected to a connection point at which the cathode of the bridge diode and the smoothing capacitor are connected, and allows residual charges in the smoothing capacitor and the X capacitor to be discharged when the AC shutoff detection signal is output, and the discharging circuit includes a JFET which has a drain terminal connected to the above connection point and lowers discharge voltage; and a first discharging switch element connected to the source terminal of the JFET.
    Type: Application
    Filed: October 10, 2013
    Publication date: February 6, 2014
    Applicant: PANASONIC CORPORATION
    Inventors: Tatsuya SAKURAI, Takashi SAJI, Tetsuyuki FUKUSHIMA
  • Patent number: 8427850
    Abstract: A switching power supply device including: a power transformer including a primary winding, a secondary winding, and an auxiliary winding; a switching element which is connected to the primary winding; an output voltage generation circuit which converts, into a direct-current voltage, a voltage induced in the secondary winding; a secondary-side on-time signal generation circuit which generates a secondary-side on-time signal indicating a secondary-side on-time; and a switching control circuit which controls a switching operation of the switching element so that the second direct-current voltage falls within a specified range, wherein the switching control circuit controls the switching operation so that the direct-current voltage becomes equal to or below an overvoltage specified value when the secondary-side on-time becomes smaller than a set value.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: April 23, 2013
    Assignee: Panasonic Corporation
    Inventors: Naohiko Morota, Tetsuyuki Fukushima, Kazuhiro Murata
  • Publication number: 20110194314
    Abstract: A switching power supply device including: a power transformer including a primary winding, a secondary winding, and an auxiliary winding; a switching element which is connected to the primary winding; an output voltage generation circuit which converts, into a direct-current voltage, a voltage induced in the secondary winding; a secondary-side on-time signal generation circuit which generates a secondary-side on-time signal indicating a secondary-side on-time; and a switching control circuit which controls a switching operation of the switching element so that the second direct-current voltage falls within a specified range, wherein the switching control circuit controls the switching operation so that the direct-current voltage becomes equal to or below an overvoltage specified value when the secondary-side on-time becomes smaller than a set value.
    Type: Application
    Filed: February 3, 2011
    Publication date: August 11, 2011
    Inventors: Naohiko MOROTA, Tetsuyuki Fukushima, Kazuhiro Murata
  • Patent number: 7035751
    Abstract: To provide a nonvolatile memory microcomputer with which a step of testing a microcomputer unit using a logic tester can be omitted, thereby reducing the testing cost. A memory tester supplies test data and expectation data to the nonvolatile memory microcomputer, and the nonvolatile memory microcomputer stores them in a nonvolatile memory. Subsequently, upon receiving an address signal, the nonvolatile memory outputs a test signal and an expectation signal based on test data and expectation data corresponding to the address signal. The test signal is supplied to a circuit block in the microcomputer unit, to drive the circuit block. The circuit block returns a test result signal, which is output to the memory tester together with the expectation signal. The memory tester compares the test result signal and the expectation signal, to judge whether the microcomputer unit operates correctly.
    Type: Grant
    Filed: October 28, 2003
    Date of Patent: April 25, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masatoshi Shinagawa, Akifumi Kawahara, Tetsuyuki Fukushima, Masakazu Kurata, Manabu Komiya
  • Publication number: 20040153924
    Abstract: To provide a nonvolatile memory microcomputer with which a step of testing a microcomputer unit using a logic tester can be omitted, thereby reducing the testing cost. A memory tester supplies test data and expectation data to the nonvolatile memory microcomputer, and the nonvolatile memory microcomputer stores them in a nonvolatile memory. Subsequently, upon receiving an address signal, the nonvolatile memory outputs a test signal and an expectation signal based on test data and expectation data corresponding to the address signal. The test signal is supplied to a circuit block in the microcomputer unit, to drive the circuit block. The circuit block returns a test result signal, which is output to the memory tester together with the expectation signal. The memory tester compares the test result signal and the expectation signal, to judge whether the microcomputer unit operates correctly.
    Type: Application
    Filed: October 28, 2003
    Publication date: August 5, 2004
    Inventors: Masatoshi Shinagawa, Akifumi Kawahara, Tetsuyuki Fukushima, Masakazu Kurata, Manabu Komiya
  • Patent number: 5654913
    Abstract: In halt period during standby time, a cell plate node potential switching circuit changes the potential of a cell plate node to a low potential that is lower than a high potential adopted in a burst refresh operation. As a result, a potential difference between both ends of a PN junction of a memory cell transistor is decreased, thereby suppressing a leakage current flowing through the PN junction. Simultaneously, a word driver circuit changes the potential of a word line to a negative potential that is lower than a normal potential adopted in the burst refresh operation. As a result, an off state of the memory cell transistor is enhanced owing to decrease of a gate-source voltage thereof, thereby suppressing a leakage current flowing from the bit line to a charge storage node.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: August 5, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd
    Inventors: Tetsuyuki Fukushima, Hiroyuki Yamauchi, Toru Iwata
  • Patent number: 4965766
    Abstract: A digital input/output circuit to be connected between an internal data bus composed of 2.sup.n signal lines (n is zero or a positive integer) and 2.sup.n external terminals includes an output port for outputting data from the internal data bus to the external terminals and an input port for inputting the data from the external terminal to the internal data bus. The output port comprises a scrambler receiving data of 2.sup.n bits from the internal data bus and a mode signal and operating for relocating the received data in accordance with the mode signal so as to output the relocated data with each unit of 2.sup.m bits (m is an integer not greater than n) indicated by the mode signal. An output circuit includes 2.sup.n output buffers each having an input connected to receive directly or indirectly an output of the scrambler and an output connected to a corresponding one of the external terminals. This output circuit operates in response to the mode signal so as to make active 2.sup.m output buffers of the 2.
    Type: Grant
    Filed: May 25, 1988
    Date of Patent: October 23, 1990
    Assignee: NEC Corporation
    Inventors: Tetsuyuki Fukushima, Satoru Kobayashi