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: 6356493
    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 as 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 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: August 11, 2000
    Date of Patent: March 12, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Publication number: 20020017923
    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: April 24, 2001
    Publication date: February 14, 2002
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Keiichi Higeta, Kunihiko Yamaguchi, Fumihiko Arakawa
  • Patent number: 6337581
    Abstract: Disclosed herein is a transmission circuit for transmitting a data signal between circuit units on a semiconductor integrated circuit through a signal wire. The data signal is transmitted by a driver circuit for precharging the signal wire to a high potential during a precharge period and discharging the signal wire to a low potential according to data to be transmitted during an evaluation period or keeping the signal wire at a high potential as floating as it is.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: January 8, 2002
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Takeshi Kusunoki, Fumihiko Arakawa
  • Patent number: 6333645
    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: September 11, 2000
    Date of Patent: December 25, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Noboru Masuda, Kenji Kaneko, Makoto Hanawa, Takeshi Kusunoki
  • Patent number: 6333881
    Abstract: One of the factors determining cycle time of an SRAM is recovery time of a bit line after writing. When the size of a precharge PMOS transistor is increased to shorten the recovery time, delay time which is caused by making the precharge PMOS transistors non-conductive at the time of read operation, that is, access time increases. To avoid this, a semiconductor memory is provided with a second precharge circuit in addition to the conventional bit line precharge circuit. The second precharge circuit operates upon detection of completion of writing and stops operation when it detects that the bit line is precharged to a high potential. Consequently, the recovery time after write operation is shortened and the cycle time is reduced without increasing the access time.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: December 25, 2001
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Takeshi Kusunoki, Fumihiko Arakawa, Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki
  • Patent number: 6316961
    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 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Noboru Masuda, Kenji Kaneko, Makoto Hanawa, Takeshi Kusunoki
  • Patent number: 6229745
    Abstract: A semiconductor memory in accordance with the present invention includes a sense amplifier composed of a plurality of MOS transistors. When the sense amplifier is on standby, a first control circuit brings an input signal of the sense amplifier to zero. A second control circuit uses voltages developed because of an offset voltage occurring in the sense amplifier to feed back the potentials in the wells of the MOS transistors so that the offset voltage will be nullified. When the offset voltage occurring in the sense amplifier is nullified, a delay time required by the sense amplifier is shortened. This results in the high-speed semiconductor memory.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: May 8, 2001
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki, Fumihiko Arakawa, Takeshi Kusunoki
  • Publication number: 20010000296
    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: Application
    Filed: November 30, 2000
    Publication date: April 19, 2001
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Noboru Masuda, Kenji Kaneko, Makoto Hanawa, Takeshi Kusunoki
  • Publication number: 20010000017
    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: Application
    Filed: November 30, 2000
    Publication date: March 15, 2001
    Inventors: Kazuo Kanetani, Hiroaki Nambu, Kaname Yamasaki, Noboru Masuda, Kenji Kaneko, Makoto Hanawa, Takeshi Kusunoki
  • Patent number: 6075729
    Abstract: A semiconductor memory has a plurality of word lines a plurality of bit line pairs and a plurality of memory cells formed at intersection points between the word lines and the bit line pairs. A word decoder generates a word line select signal upon receipt of an address signal and a bit decoder generates a bit line select signal on receiving the address signal. A bit line load circuit receives a signal current from the applicable memory cell, a sense circuit detects an output signal from the bit line load circuit, and a bit line pull-down circuit and a bit line recovery circuit drives the applicable bit lines upon writing data to the memory cell in question.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: June 13, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Kenichi Ohhata, Fumihiko Arakawa, Takeshi Kusunoki, Hiroaki Nambu, Kazuo Kanetani, Kaname Yamasaki, Keiichi Higeta
  • Patent number: 5523966
    Abstract: Disclosed is a static type memory cell with high immunity from alpha ray-induced soft errors. The memory cell has a coupling capacitance C.sub.c between two data storage nodes 1 and 2. The p-well (or p-substrate) in which the driver-MOS transistors MN3, MN4 and the transfer MOS transistors MN1, MN2 are formed is connected to a V.sub.bb generator. The voltage V.sub.bb is set lower than the low level V.sub.L of the memory cell signal potential. Even when the potential variation .DELTA.V.sub.L of the low-voltage side node 2 is large, the parasitic diode present between the n-type diffusion layer corresponding to the source or drain of MN1-MN4 and the p-well (or p-substrate) does not turn on. Erroneous operations can therefore be prevented.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: June 4, 1996
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Youji Idei, Hiroaki Nambu, Kazuo Kanetani, Toru Masuda, Kunihiko Yamaguchi, Kenichi Ohhata, Takeshi Kusunoki
  • Patent number: 5448527
    Abstract: A decoder formed of multiple circuit blocks each including bipolar transistors Q1 and Q2 having their collectors connected to resistors R1 and R2, respectively, a bipolar transistor Q3 having its collector supplied with a power voltage, and a current source I1 connected commonly to the emitters of Q1-Q3. This circuit configuration permits the decoder and BiCMOS memories using it to operate with a low supply voltage.
    Type: Grant
    Filed: November 10, 1993
    Date of Patent: September 5, 1995
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Noriyuki Homma, Kazuo Kanetani, Youji Idei, Kenichi Ohhata, Takesi Kusunoki
  • Patent number: 5402377
    Abstract: A semiconductor memory device has a primary memory cell array, a primary decoder having a first circuit producing an intermediate signal from an address signal and a second circuit producing a first cell selection signal from the intermediate signal for selectively driving a word line and a bit line, an auxiliary memory cell array having a plurality of memory cells, each being used for a defective memory cell found in the primary memory cell array, an auxiliary decoder connected to the primary decoder to receive the intermediate signal, a non-volatile memory for storing first information indicating that the primary memory cell array contains a defective memory cell from which a cell defect signal is produced and for storing second information indicating an address of the defective memory cell from which a defective cell address signal is produced, and a control circuit responsive to the cell defect signal and the defective cell address signal for producing a first control signal to be supplied to the second c
    Type: Grant
    Filed: May 17, 1994
    Date of Patent: March 28, 1995
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Kenichi Ohhata, Hiroaki Nambu, Kazuo Kanetani, Youji Idei, Takeshi Kusunoki, Toru Masuda
  • Patent number: 5398201
    Abstract: A circuit technique suitable to attain a high speed of a memory which is constructed in a manner such that memory cells include a field effect transistor and peripheral circuits include a bipolar transistor and a field effect transistor. According to the invention, a bipolar transistor whose collector is connected to a differential amplifier and which supplies a current to the differential amplifier in accordance with a signal which is inputted to a base or an emitter is added, and a bipolar transistor to supply a current only when writing to bit lines is connected. According to the invention, a high speed of the access time when information is read out by switching the selection bit line is accomplished. Further, the charge/discharge time of the bit line when information is written is reduced and a high speed of the writing time can be also accomplished.
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: March 14, 1995
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Noriyuki Homma, Kunihiko Yamaguchi, Hisayuki Higuchi, Kazuo Kanetani, Youji Idei, Ken'ichi Ohata, Yoshiaki Sakurai, Masanori Odaka, Goro Kitsukawa
  • Patent number: 5255225
    Abstract: A semiconductor integrated circuit device including a level conversion circuit in which the simplifying of the circuit and the increasing of the speed of operation have been attained is provided.A pair of complementary output signals amplified to a required signal level by a current switch circuit including differential transistors which receive an input signal and a reference voltage are inputted into a pair of emitter follower circuits. An emitter follower output transistor is driven by an output signal from one emitter follower circuit, while an N-channel MOSFET provided between the output transistor and a current source used as a load is driven by an output signal from the other emitter follower circuit, to obtain a level-amplified output signal from an emitter of the output transistor.
    Type: Grant
    Filed: March 4, 1992
    Date of Patent: October 19, 1993
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Noriyuki Homma, Kunihiko Yamaguchi, Kazuo Kanetani, Hisayuki Higuchi, Youji Idei, Kenichi Ohata, Yoshiaki Sakurai, Masanori Odaka, Goro Kitsukawa, Nobuo Tamba, Masayuki Ohayashi, Toshiro Hiramoto, Kayoko Saito
  • Patent number: 5163022
    Abstract: The disclosure includes feeding a current I.sub.R to only BIT lines selected, or feeding current I.sub.R transiently to only the BIT lines switched from unselected to selected states; and a sense amplifier for detecting the difference between the currents flowing in selected BIT lines to read out stored information, wherein current I.sub.R and cell current I.sub.cell have a relation of I.sub.R >I.sub.cell. The BiC MOS memory has high speed, low power and high integration density. Diodes are provided between the memory cell and the BIT lines.
    Type: Grant
    Filed: January 30, 1992
    Date of Patent: November 10, 1992
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Noriyuki Homma, Hiroaki Nambu, Kunihiko Yamaguchi, Tohru Nakamura, Youji Idei, Kazuo Kanetani, Kenichi Ohhata, Yoshiaki Sakurai, Hisayuki Higuchi
  • Patent number: 5086414
    Abstract: A semiconductor circuit having a plurality of circuit blocks, each having latch circuits each one thereof being controlled by an internally provided clock signal for preventing malfunction of the circuit. Each circuit is provided with the latch function so that the cycle time is made shorter than the access time. Moreover, the latch means are driven in such a manner that the adjoining ones are prevented from being put to through-state simultaneously, whereby malfunction is prevented.
    Type: Grant
    Filed: November 15, 1989
    Date of Patent: February 4, 1992
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Hiroaki Nambu, Noriyuki Homma, Kunihiko Yamaguchi, Kazuo Kanetani, Youji Idei, Kenichi Ohhata, Yoshiaki Sakurai, Jun Etoh
  • Patent number: 4986666
    Abstract: A semiconductor memory device capable of operating at high speeds, and a sense circuit and a decoder circuit that can be suitably used for the memory device. A latch function is imparted to at least either one of the decoder circuit or the sense circuit in the semiconductor memory device.
    Type: Grant
    Filed: November 29, 1988
    Date of Patent: January 22, 1991
    Assignees: Hitachi Device Engineering Co., Ltd., Hitachi Ltd.
    Inventors: Noriyuki Homma, Hisayuki Higuchi, Yoji Idei, Hiroaki Nambu, Yoshiaki Sakurai
  • Patent number: 4642486
    Abstract: This invention is effective in the speeding up of a decoder circuit and maintenance of output amplitude. The invention is characterized in that, in a decoder circuit composed of a multi-emitter transistor or at least one diode group in which the anodes of a plurality of diodes are connected, and a charge circuit having an output emitter follower transistor, the multi-emitter transistor or the forward voltage of the diodes are larger than the voltage between the base and the emitter of the output emitter follower transistor.
    Type: Grant
    Filed: December 27, 1984
    Date of Patent: February 10, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Noriyuki Honma, Hiroaki Nambu, Isao Yoshida, Hisayuki Higuchi, Kunihiko Yamaguchi