Patents by Inventor Akira Kitaguchi

Akira Kitaguchi 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: 7952506
    Abstract: There is provided a technique for reducing the adverse effect of idle tones in the channels in a ??-type A/D converter including a plurality of channels for converting analog input signals into digital signals. The ??-type A/D converter includes an L channel for converting a left analog input signal into a digital signal and an R channel for converting a right analog input signal into a digital signal. Each of the L channel and the R channel includes a DC dither circuit for generating a DC addition voltage for shifting the frequency of an idle tone. In the L channel and the R channel, DC addition voltages generated by DC dither circuits are different from each other.
    Type: Grant
    Filed: October 25, 2010
    Date of Patent: May 31, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Toshio Kumamoto, Takashi Okuda, Tatsuo Sengoku, Akira Kitaguchi
  • Publication number: 20110037633
    Abstract: There is provided a technique for reducing the adverse effect of idle tones in the channels in a ??-type A/D converter including a plurality of channels for converting analog input signals into digital signals. The ??-type A/D converter includes an L channel for converting a left analog input signal into a digital signal and an R channel for converting a right analog input signal into a digital signal. Each of the L channel and the R channel includes a DC dither circuit for generating a DC addition voltage for shifting the frequency of an idle tone. In the L channel and the R channel, DC addition voltages generated by DC dither circuits are different from each other.
    Type: Application
    Filed: October 25, 2010
    Publication date: February 17, 2011
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Toshio KUMAMOTO, Takashi Okuda, Tatsuo Sengoku, Akira Kitaguchi
  • Patent number: 7847714
    Abstract: There is provided a technique for reducing the adverse effect of idle tones in the channels in a ??-type A/D converter including a plurality of channels for converting analog input signals into digital signals. The ??-type A/D converter includes an L channel for converting a left analog input signal into a digital signal and an R channel for converting a right analog input signal into a digital signal. Each of the L channel and the R channel includes a DC dither circuit for generating a DC addition voltage for shifting the frequency of an idle tone. In the L channel and the R channel, DC addition voltages generated by DC dither circuits are different from each other.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: December 7, 2010
    Assignee: Renesas Electronics Corporation
    Inventors: Toshio Kumamoto, Takashi Okuda, Tatsuo Sengoku, Akira Kitaguchi
  • Publication number: 20090267816
    Abstract: There is provided a technique for reducing the adverse effect of idle tones in the channels in a ??-type A/D converter including a plurality of channels for converting analog input signals into digital signals. The ??-type A/D converter includes an L channel for converting a left analog input signal into a digital signal and an R channel for converting a right analog input signal into a digital signal. Each of the L channel and the R channel includes a DC dither circuit for generating a DC addition voltage for shifting the frequency of an idle tone. In the L channel and the R channel, DC addition voltages generated by DC dither circuits are different from each other.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 29, 2009
    Inventors: Toshio KUMAMOTO, Takashi OKUDA, Tatsuo SENGOKU, Akira KITAGUCHI
  • Patent number: 6114866
    Abstract: A semiconductor device test board solves a problem with conventional test boards in that test results obtained through a burn-in procedure could be identified only before the test board is taken out of a burn-in oven. Hence, conventional test boards required additional steps for checking the test results after removing the test boards from the burn-in oven. This extra step prevents the efficiency of the test from being improved. One embodiment of the present test board has indicator arms, each rotatably mounted on a pivot on the test board, for indicating, in response to a signal on a signal line, the test result of the semiconductor device associated with it. Each of the indicator arms maintains its rest position when no failure has occurred in the semiconductor device associated with it during the test.
    Type: Grant
    Filed: February 4, 1998
    Date of Patent: September 5, 2000
    Assignees: Mitsubishi Electric Systems LSI Design Corporation, Mitsubishi Denki Kabushiki
    Inventors: Masaaki Matsuo, Tsuyoshi Saitoh, Takekazu Yamashita, Michio Nakajima, Akira Kitaguchi, Hideki Toki
  • Patent number: 6092227
    Abstract: A test circuit includes a writing unit that outputs m-bit data captured upon receipt of a clock signal, branches the m-bit data n identical m-bit data signals, and stores the n m-bit data signals in a memory device. A function determining unit reads the n m-bit data signals from the memory, compares one of the n m-bit data signals to an m-bit expected value, and determines coincidence or non-coincidence between the n m-bit data signal and an expected value.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: July 18, 2000
    Assignees: Mitsubishi Electric System LSI Design Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideki Toki, Akira Kitaguchi, Makoto Hatakenaka, Kiyoyuki Shiroshima, Masaaki Matsuo, Tsuyoshi Saitoh
  • Patent number: 6043522
    Abstract: A semiconductor device capable of solving a problem of a conventional semiconductor device in that a high density integration cannot be expected because each cell, which includes a pair of N and P wells disposed adjacently, requires a countermeasure against latchup individually. The high density integration prevents an effective countermeasure against latchup. The present semiconductor device arranges two cells, which are adjacent in the direction of an alignment of the N wells and P wells, in opposite directions so that two P wells (or two N wells) of the two adjacent cells are disposed successively, and includes an isolation layer extending across the two adjacent cells to enclose the two successively disposed P wells, thereby isolating the two P wells collectively from the substrate.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: March 28, 2000
    Assignees: Mitsubishi Electric System LSI Design Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Michio Nakajima, Makoto Hatakenaka, Akira Kitaguchi, Kiyoyuki Shiroshima, Takekazu Yamashita, Masaaki Matsuo
  • Patent number: 6040614
    Abstract: A semiconductor integrated circuit includes a fuse element located on an insulating layer. The surface of the insulating layer is substantially smooth. The insulating layer is located over a capacitor. Wiring is located on the insulation layer. The fuse element and the wiring include the same material.
    Type: Grant
    Filed: March 3, 1998
    Date of Patent: March 21, 2000
    Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric System LSI Design Corporation
    Inventors: Akira Kitaguchi, Makoto Hatakenaka, Michio Nakajima, Kaoru Motonami, Kiyoyuki Shiroshima, Takekazu Yamashita
  • Patent number: 6025733
    Abstract: A semiconductor memory device includes two subcircuits each including a memory circuit, a semiconductor circuit, and a logical circuit. Connection pads are divided into only two parallel rows located along the outer periphery of the semiconductor memory device. Each of the pads may include a probe region against which a probe is pressed for testing the semiconductor memory circuit, and a wire region to which a wire is connected upon packaging.
    Type: Grant
    Filed: February 3, 1998
    Date of Patent: February 15, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tuyoshi Saitoh, Akira Kitaguchi, Masaaki Matsuo, Makoto Hatakenaka, Toshio Nakano, Yuko Sudo
  • Patent number: 5926429
    Abstract: A semiconductor memory device includes memory elements, each maintaining memory contents within a period of time during which a refresh operation is repeated, and a refresh request circuit for making a refresh request. The semiconductor memory device includes refreshing circuits each of which, in response to a refresh request from the refresh request circuit, performs a refresh operation on a different number of memory elements at the same time, and a selecting circuit for selecting one refreshing circuit from among the refreshing circuits according to the number of memory elements included in the semiconductor memory device. The refresh request circuit can change the interval at which it makes a refresh request.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: July 20, 1999
    Assignees: Mitsubishi Electric System LSI Design Corporation, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tsuyoshi Saitoh, Kiyoyuki Shiroshima, Michio Nakajima, Masaaki Matsuo, Nobuyuki Fujii, Akira Kitaguchi
  • Patent number: 5453993
    Abstract: Disclosed is a semiconductor integrated circuit which can be tested with a high-speed clock of actual operation level or more, even if a relatively low-priced IC tester which is not capable of supplying high-speed clocks is employed, and a method of testing the same. An exclusive OR gate (2) of the semiconductor integrated circuit receives the first test clock (TCLK1) through the first test clock input pin (P1) into the first input and the second test clock (TCLK2) through the second test clock input pin (P2) into the second input, to output a high-speed clock (SCLK) resulting from the test clocks to an A input of a selector (3). Thus, the semiconductor interacted circuit internally generates the high-speed clock having higher frequency than that of the test clock to operate an internal circuit, thereby being tested with clock frequency of actual operation level or more even by means of the relatively low-priced IC tester.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: September 26, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akira Kitaguchi, Masaharu Taniguchi