Patents by Inventor Hiroaki Nambu

Hiroaki Nambu 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: 6842394
    Abstract: A high-speed, reduced power consumption address decoder circuit, wherein a decoder control signal ?2 is rendered unnecessary between an address buffer control signal?1 and the decoder control signal ?2, thereby implementing speed-up in operation of a decoder circuit. Improved speed and reduced power consumption are attained by a configuration wherein a buffer is integrated with a decoder, so that an output current path of transistors making up the address buffer, and that of transistors making up the decoder are connected with each other in series, thereby forming an output current path of decoder output. With the invention, speed-up in operation, lower power consumption, and higher cycle, of decoder circuits, can be achieved. Further, in the case of using the decoder circuits in a semiconductor memory, it is possible to achieve shortening of access time, lower power consumption, and higher cycle with reference to the semiconductor memory.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: January 11, 2005
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu
  • Patent number: 6806516
    Abstract: Disclosed herewith is a semiconductor device improved to prevent withstand voltage defects that might occur in each MOSFET used therein and a system to be designed easily and prevented from withstand voltage defects that might occur in each semiconductor used therein. The system includes the first and second input circuits, each being constituted by MOSFETs manufactured in the same process. The first input circuit receives a voltage of a first signal inputted from a first external terminal and divided by first and second resistor means while the AC component of the input signal is transmitted to the input circuit through a capacitor disposed in parallel to the first resistor means. The second input circuit receives a second input signal inputted from a second external terminal and reduced in signal amplitude so as to become smaller than that of the first input signal.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: October 19, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Takemi Negishi, Hiroaki Nambu, Kazuo Kanetani, Hideto Kazama
  • Patent number: 6807115
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Grant
    Filed: February 10, 2003
    Date of Patent: October 19, 2004
    Assignees: Renesas Technology Corporation, Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20040183582
    Abstract: The present invention provides a semiconductor integrated circuit in which a timing margin for fetching data is prevented from being reduced even in the case where the duty ratio of a clock signal is different from 50%. The semiconductor integrated circuit includes: a clock input terminal for receiving a clock signal; a data input terminal for receiving a data signal; internal clock generating circuits for generating an internal clock signal which is switched at an intermediate timing between the i-th (i: an integer of 1 or larger) switch timing and the (i+1)th switch timing of the clock signal; and a latch circuit for latching the data signal synchronously with the internal clock signal. An internal clock signal which is switched at an intermediate timing between the i-th switch timing and the (i+1)th switch timing of the clock signal is generated and the data signal is fetched synchronously with the internal clock signal.
    Type: Application
    Filed: February 2, 2004
    Publication date: September 23, 2004
    Inventors: Hiroaki Nambu, Masao Shinozaki, Kazuo Kanetani, Hideto Kazama
  • Patent number: 6791895
    Abstract: A semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: September 14, 2004
    Assignee: Renesas Technology Corporation
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Publication number: 20040169527
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit is composed by a semiconductor logic circuit wherein the number of columns of transistors for pulling down at an output node is small even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced.
    Type: Application
    Filed: January 12, 2004
    Publication date: September 2, 2004
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Publication number: 20040057329
    Abstract: Disclosed herein is a semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Application
    Filed: September 29, 2003
    Publication date: March 25, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Patent number: 6677782
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit is composed by a semiconductor logic circuit wherein the number of columns of transistors for pulling down at an output node is small even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced. According to the present invention, the operation of the decoder circuit can be sped up, the power consumption can be reduced, the cycles can be increased and in a semiconductor memory for example, the reduction of access time and power consumption and the increase of the cycles are enabled.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: January 13, 2004
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Publication number: 20030222285
    Abstract: Disclosed herewith is a semiconductor device improved to prevent withstand voltage defects that might occur in each MOSFET used therein and a system to be designed easily and prevented from withstand voltage defects that might occur in each semiconductor used therein. The system includes the first and second input circuits, each being constituted by MOSFETs manufactured in the same process. The first input circuit receives a voltage of a first signal inputted from a first external terminal and divided by first and second resistor means while the AC component of the input signal is transmitted to the input circuit through a capacitor disposed in parallel to the first resistor means. The second input circuit receives a second input signal inputted from a second external terminal and reduced in signal amplitude so as to become smaller than that of the first input signal.
    Type: Application
    Filed: February 21, 2003
    Publication date: December 4, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takemi Negishi, Hiroaki Nambu, Kazuo Kanetani, Hideto Kazama
  • Patent number: 6657887
    Abstract: A semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells capable of improved noise margin, faster read rate and reduced power consumption is formed using an operating voltage of the memory cell that is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Grant
    Filed: July 22, 2002
    Date of Patent: December 2, 2003
    Assignee: Renesas Technology Corporation
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Patent number: 6617610
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: September 9, 2003
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20030123309
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Application
    Filed: February 10, 2003
    Publication date: July 3, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20030107943
    Abstract: It is an object of the invention to provide a circuit configuration wherein a decoder control signal &PHgr;2 is rendered unnecessary between an address buffer control signal &PHgr;1 and the decoder control signal &PHgr;2, thereby implementing speed-up in operation of a decoder circuit. The object is attained by adoption of a configuration wherein a buffer is integrated with a decoder, so that an output current path of transistors making up the address buffer, and that of transistors making up the decoder are connected with each other in series, thereby forming an output current path of decoder output. With the invention, speed-up in operation, lower power consumption, and higher cycle, of decoder circuits, can be achieved. Further, in the case of using the decoder circuits in a semiconductor memory, it is possible to achieve shortening of access time, lower power consumption, and higher cycle with reference to the semiconductor memory.
    Type: Application
    Filed: October 2, 2002
    Publication date: June 12, 2003
    Applicants: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu
  • Publication number: 20030031044
    Abstract: Disclosed herein is a semiconductor memory device having a memory array comprising CMOS flip-flop circuit type memory cells, which is capable of improving a noise margin, making a read rate fast and reducing power consumption. In the semiconductor memory device, an operating voltage of the memory cell is set higher than an operating voltage of each of peripheral circuits. Threshold voltages of MOS transistors that constitute the memory cell, are set higher than those of MOS transistors constituting the peripheral circuit. A gate insulting film for the MOS transistors that constitute the memory cell, is formed so as to be regarded as thicker than a gate insulting film for the MOS transistors constituting the peripheral circuit when converted to an insulating film of the same material. Further, a word-line selection level and a bit-line precharge level are set identical to the level of the operating voltage of the peripheral circuit.
    Type: Application
    Filed: July 22, 2002
    Publication date: February 13, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Keiichi Higeta, Shigeru Nakahara, Hiroaki Nambu
  • Publication number: 20020196053
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit is composed by a semiconductor logic circuit wherein the number of columns of transistors for pulling down at an output node is small even if the number of inputs is many and the true and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced.
    Type: Application
    Filed: August 29, 2002
    Publication date: December 26, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Patent number: 6476644
    Abstract: A clocked logic gate circuit is constituted so that a switch unit is constituted by a logic block and a reference MOS transistor, the source of the reference MOS transistor is connected to one output of the logic block, the gate of the reference MOS transistor is connected to the other output of the logic block, and MOS transistors (input transistors) constituting the logic block are connected in parallel. With this arrangement, complementary inputs are not required and a driving MOS transistor and an input transistor (or a driving MOS transistor and a reference MOS transistor) can be connected in series. As a result, a circuit is obtained which is simpler than the double rail logic in constitution is facilitated and can be operated at a higher speed than a CMOS logic circuit and a path transistor logic circuit.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: November 5, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Noboru Masuda, Kenji Kaneko, Makoto Hanawa, Takeshi Kusunoki
  • Patent number: 6438050
    Abstract: A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic is configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: August 20, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Publication number: 20020098602
    Abstract: In a dynamic-type semiconductor integrated circuit in which precharge and evaluation operations are preformed per cycle, an IDDQ test and a light detection test can be conducted during an evaluation period for facilitating diagnosis and failure analysis so as to increase test accuracy. The dynamic-type semiconductor integrated circuit operates in a normal operation mode or a test mode, wherein a switch therebetween is triggered by a mode selection signal. In the normal operation mode, the pulse width of an internal activation signal is controlled to be constant, i.e., invariable with an operation cycle time length. In the test mode, the pulse width of the internal activation signal is controlled to vary according to an operation cycle time length.
    Type: Application
    Filed: December 13, 2001
    Publication date: July 25, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki, Keiichi Higeta
  • Publication number: 20020057612
    Abstract: A transmission circuit for transmitting a data signal between circuit units through a signal wire. The data signal is transmitted for precharging the signal wire to high potential during a precharge period and discharging it to low potential according to data transmitted during an evaluation period or keeping the signal wire as it is. Latch type Source-Coupled-Logic is configured so that a first node and a second node used as an output terminal to the next stage are respectively charged together to high potential during the precharge period. The second node is discharged according to a potential at the first node during the evaluation period, and the first node is discharged according to a potential on the signal wire. Thus, the operation of discharging the signal wire by the driver circuit can be sped up.
    Type: Application
    Filed: January 8, 2002
    Publication date: May 16, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Patent number: 6369617
    Abstract: To speed up the operation of a decoder circuit, reduce the power consumption of the decoder circuit and increase the cycle, each circuit such as a buffer, a predecoder and a main decoder in the decoder circuit include a semiconductor logic circuit wherein the number of columns of transistors for pulling down an output node is small even if the number of inputs is large, and the true output signal and a complementary output signal having approximately the same delay time are acquired and the output pulse length of each circuit in the decoder circuit is reduced. By virtue of this arrangement, the operation of the decoder circuit can be sped up, the power consumption can be reduced, the cycles can be increased and, in a semiconductor memory, for example, the reduction of access time and power consumption and the increase of the cycles are enabled.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: April 9, 2002
    Assignees: Hitachi, Ltd., Hitachi ULSI Systems Co., Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa