Patents by Inventor Shigeru Atsumi

Shigeru Atsumi 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: 20040240271
    Abstract: There are provided a boosted voltage generating circuit and a semiconductor memory device having the boosted voltage generating circuit which includes a booster circuit for outputting high voltage obtained by boosting the power supply voltage, a regulator circuit supplied with the high voltage, for generating voltage whose voltage value is smaller than the value of the high voltage and which is variably set to at least two values based on the high voltage at the operating time, and a equalizer circuit connected to the booster circuit and regulator circuit, for short-circuiting an output node of the booster circuit and an output node of the regulator circuit in response to a first control signal, wherein the operative period of the regulator circuit and the short-circuiting operation period of the equalizer circuit do not overlap each other.
    Type: Application
    Filed: June 14, 2004
    Publication date: December 2, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Takeshi Miyaba, Shigeru Atsumi
  • Patent number: 6826068
    Abstract: A semiconductor integrated circuit device includes first to fourth bit lines and a redundant bit line, first to fourth column gate transistors and a redundant column gate transistor coupled to each of the first to fourth bit lines and the redundant bit lines, first to fourth column select lines and a redundant column select line coupled to each of the first to fourth column gate transistors and the redundant column gate transistor. The second column select line passes through the first bit line. The third column select line passes through the first and second bit lines. The fourth column select line passes through the first, second and third bit lines. The redundant column select line passes through the first, second, third and fourth bit lines.
    Type: Grant
    Filed: September 3, 2003
    Date of Patent: November 30, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Shiga, Yoshinori Takano, Toru Tanzawa, Shigeru Atsumi
  • Patent number: 6801457
    Abstract: A non-volatile semiconductor memory comprises a memory cell array having a plurality of non-volatile memory cells, at least one reference cell, a read circuit for reading data by applying a first voltage to one of word lines to compare a current flowing through one of bit lines with a current flowing through the reference cell, an erase circuit for erasing the data by applying a voltage to at least two selected from the word lines, the bit lines, the source lines and a semiconductor region including the memory cells, first and second regulators, and an erase verify circuit for detecting whether the erase has finished by applying an output voltage of the first regulator to word lines of the memory cells to be erased, while applying an output voltage of the second regulator to a word line of the reference cell, thereby comparing a cell current of selected one of the memory cells with a cell current of the reference cell.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: October 5, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi
  • Patent number: 6795352
    Abstract: The semiconductor memory comprises a reference current generator, first and second current converters, sense amplifiers for read, and sense amplifiers for verify. The reference current generator generates a first voltage dependent upon the current flowing through a reference cell. The first current converters, to which the first voltage is input, each generate a second voltage. The second current converters, to which the first voltage is input, each generate a third voltage. The sense amplifiers for read output data of a selection memory cell, comparing the voltage of the data-line for read with the second voltage. The sense amplifiers for verify output verify data of the selection memory cell, comparing the voltage of the data-lines for verify and the third voltage.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: September 21, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi, Akira Umezawa, Tadayuki Taura, Hitoshi Shiga, Yoshinori Takano
  • Patent number: 6788601
    Abstract: A semiconductor memory device comprises memory cell array, a sense amp, and a reference voltage generator. The reference voltage generator includes a reference cell unit containing a reference cell to flow a reference current and a first current source load to supply a current to the reference cell; a reference transistor unit containing a reference transistor to flow a current reflecting the reference current and a second current source load to supply a current to the reference transistor; a control amp for negative feedback control of the reference transistor; a current source transistor; and a third current source load connected to a reference sense line.
    Type: Grant
    Filed: November 26, 2002
    Date of Patent: September 7, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshinori Takano, Shigeru Atsumi, Toru Tanzawa
  • Patent number: 6781879
    Abstract: A first address subset is allocated as a first column address in a nonvolatile semiconductor memory. In addition, a second address subset higher in order than the first address subset is allocated as a first row address. Furthermore, a third address subset higher in order than the second address subset is allocated as a second column address.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: August 24, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi
  • Patent number: 6781439
    Abstract: A standby-mode booster circuit is activated in both a standby mode and an active mode and boosts up a power supply voltage to generate a booster voltage and output it from an output terminal. An active-mode booster circuit is activated in the active mode. In the active-mode booster circuit, an NMOS transistor is first turned on in response to a reset signal supplied from a reset signal generation circuit and then a connection node of capacitors is reset to the power supply voltage by the NMOS transistor. The boost operation is then started to output the booster voltage from the output terminal.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: August 24, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi
  • Publication number: 20040160827
    Abstract: A nonvolatile semiconductor memory device includes a first memory cell array including electrically re-programmable main memory cells, a second memory cell array including electrically data-programmable redundancy memory cells, a first storage configured to store a specified code, a first comparator configured to compare a selected code with the specified code to generate an activating signal, a faulty address latch circuit configured to be activated by the activating signal and controlled to temporarily latch a fault address corresponding to the fault, a second storage configured to store the faulty address latched by the faulty address latch circuit, a second comparator configured to compare an input address with the faulty address to generate a replacement control signal when the input address coincides with the faulty address, and a replacing circuit configured to replace an output of the first memory cell array with an output of the second memory cell array.
    Type: Application
    Filed: February 20, 2004
    Publication date: August 19, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tadayuki Taura, Shigeru Atsumi, Toru Tanzawa
  • Patent number: 6771547
    Abstract: There are provided a boosted voltage generating circuit and a semiconductor memory device having the boosted voltage generating circuit which includes a booster circuit for outputting high voltage obtained by boosting the power supply voltage, a regulator circuit supplied with the high voltage, for generating voltage whose voltage value is smaller than the value of the high voltage and which is variably set to at least two values based on the high voltage at the operating time, and a equalizer circuit connected to the booster circuit and regulator circuit, for short-circuiting an output node of the booster circuit and an output node of the regulator circuit in response to a first control signal, wherein the operative period of the regulator circuit and the short-circuiting operation period of the equalizer circuit do not overlap each other.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: August 3, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Takeshi Miyaba, Shigeru Atsumi
  • Publication number: 20040136239
    Abstract: A semiconductor integrated circuit device includes nonvolatile memory cell, a source of the cell receiving a ground potential, and a gate of the cell receiving a first control signal; a transistor, a source of the transistor receiving a drain potential of the cell, and a gate of the transistor receiving a second control signal; and a controller. The controller receives a third control signal generated upon detection of power-on and outputs the first and second control signals. A potential of the first control signal changes from the ground potential to a potential different from the ground potential, which is maintained during a first period of time, and a potential of the second control signal changes from the ground potential to a potential different from the ground potential, which is maintained during a second period of time.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Shigeru Atsumi, Masao Kuriyama, Akira Umezawa, Hironori Banba, Tadayuki Taura, Hidetoshi Saito
  • Publication number: 20040090851
    Abstract: A nonvolatile semiconductor memory includes first and second nonvolatile memory banks, a data-line for read, a data-line for program and verify, a sense amplifier for read, a sense amplifier for program and verify, and a program circuit. The data-lines are arranged in a region between the first and second nonvolatile memory banks, and selectively connected to the bit-lines of the first and second nonvolatile memory banks. The sense amplifier for read is connected to the data-line for read. The sense amplifier for program and verify and the program circuit are connected to the data-line for program and verify.
    Type: Application
    Filed: November 5, 2003
    Publication date: May 13, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toru Tanzawa, Shigeru Atsumi, Akira Umezawa, Tadayuki Taura, Hitoshi Shiga, Yoshinori Takano
  • Publication number: 20040062116
    Abstract: A semiconductor memory device comprises memory cell array, a sense amp, and a reference voltage generator.
    Type: Application
    Filed: November 26, 2002
    Publication date: April 1, 2004
    Inventors: Yoshinori Takano, Shigeru Atsumi, Toru Tanzawa
  • Publication number: 20040062111
    Abstract: A non-volatile semiconductor memory comprises a memory cell array having a plurality of non-volatile memory cells, at least one reference cell, a read circuit for reading data by applying a first voltage to one of word lines to compare a current flowing through one of bit lines with a current flowing through the reference cell, an erase circuit for erasing the data by applying a voltage to at least two selected from the word lines, the bit lines, the source lines and a semiconductor region including the memory cells, first and second regulators, and an erase verify circuit for detecting whether the erase has finished by applying an output voltage of the first regulator to word lines of the memory cells to be erased, while applying an output voltage of the second regulator to a word line of the reference cell, thereby comparing a cell current of selected one of the memory cells with a cell current of the reference cell.
    Type: Application
    Filed: September 22, 2003
    Publication date: April 1, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi
  • Patent number: 6711057
    Abstract: A nonvolatile semiconductor memory device comprises a first memory cell array including electrically re-programmable main memory cells, a second memory cell array including electrically data-programmable redundancy memory cells, a first storage configured to store a specified code, a first comparator configured to compare a selected code with the specified code to generate an activating signal, a faulty address latch circuit configured to be activated by the activating signal and controlled to temporarily latch a fault address corresponding to the fault, a second storage configured to store the faulty address latched by the faulty address latch circuit, a second comparator configured to compare an input address with the faulty address to generate a replacement control signal when the input address coincides with the faulty address, and a replacing circuit configured to replace an output of the first memory cell array with an output of the second memory cell array.
    Type: Grant
    Filed: September 5, 2002
    Date of Patent: March 23, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadayuki Taura, Shigeru Atsumi, Toru Tanzawa
  • Patent number: 6707733
    Abstract: A semiconductor memory device comprises memory cell blocks, a first redundancy cell array for each of the memory blocks, a redundancy cell block, a second redundancy cell array for the redundancy block, a first defect rescuing circuit configured to output a replacement signal for replacing a defective cell array in the redundancy block with the first redundancy array, and a second defect rescuing circuit configured to output a replacement signal for replacing a defective memory block with the redundancy block, wherein the first defect rescuing circuit has a gate circuit which outputs the output replacement signal of the first address sensing circuit as valid at an address at which the second defect rescuing circuit is not implemented, and which outputs a signal indicating which block is a defective block outputted by the second defect rescuing circuit as valid at an address at which the second defect rescuing circuit is implemented.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: March 16, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadayuki Taura, Shigeru Atsumi, Shuji Maeda
  • Patent number: 6700817
    Abstract: A semiconductor integrated circuit device includes a nonvolatile memory cell, a source of the cell receiving a ground potential, and a gate of the cell receiving a first control signal; a transistor, a source of the transistor receiving a drain potential of the cell, and a gate of the transistor receiving a second control signal; and a controller. The controller receives a third control signal generated upon detection of power-on and outputs the first and second control signals. A potential of the first control signal changes from the ground potential to a potential different from the ground potential, which is maintained during a first period of time, and a potential of the second control signal changes from the ground potential to a potential different from the ground potential, which is maintained during a second period of time.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: March 2, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shigeru Atsumi, Masao Kuriyama, Akira Umezawa, Hironori Banba, Tadayuki Taura, Hidetoshi Saito
  • Patent number: 6693818
    Abstract: A semiconductor integrated circuit includes first to eighth column selection transistors and ninth to twelfth column selection transistors. The ninth column selection transistor is connected to the first and second column selection transistors. The tenth column selection transistor is connected to the third and fourth column selection transistors. The eleventh column selection transistor is connected to the fifth and sixth column selection transistors. The twelfth column selection transistor is connected to the seventh and eighth column selection transistors. A first column selection line is connected to gates of the first, third, fifth and seventh column selection transistors. A second column selection line is connected to gates of the second, fourth, sixth and eighth column selection transistors. Third to sixth column selection lines are connected to gates of the ninth to twelfth column selection transistors, respectively.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: February 17, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Shiga, Yoshinori Takano, Toru Tanzawa, Shigeru Atsumi
  • Patent number: 6671203
    Abstract: A nonvolatile semiconductor memory includes first and second nonvolatile memory banks, a data-line for read, a data-line for program and verify, a sense amplifier for read, a sense amplifier for program and verify, and a program circuit. The data-lines are arranged in a region between the first and second nonvolatile memory banks, and selectively connected to the bit-lines of the first and second nonvolatile memory banks. The sense amplifier for read is connected to the data-line for read. The sense amplifier for program and verify and the program circuit are connected to the data-line for program and verify.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: December 30, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi, Akira Umezawa, Tadayuki Taura, Hitoshi Shiga, Yoshinori Takano
  • Patent number: 6650570
    Abstract: A non-volatile semiconductor memory comprises a memory cell array having a plurality of non-volatile memory cells, at least one reference cell, a read circuit for reading data by applying a first voltage to one of word lines to compare a current flowing through one of bit lines with a current flowing through the reference cell, an erase circuit for erasing the data by applying a voltage to at least two selected from the word lines, the bit lines, the source lines and a semiconductor region including the memory cells, first and second regulators, and an erase verify circuit for detecting whether the erase has finished by applying an output voltage of the first regulator to word lines of the memory cells to be erased, while applying an output voltage of the second regulator to a word line of the reference cell, thereby comparing a cell current of selected one of the memory cells with a cell current of the reference cell.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: November 18, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Shigeru Atsumi
  • Publication number: 20030210089
    Abstract: There are provided a boosted voltage generating circuit and a semiconductor memory device having the boosted voltage generating circuit which includes a booster circuit for outputting high voltage obtained by boosting the power supply voltage, a regulator circuit supplied with the high voltage, for generating voltage whose voltage value is smaller than the value of the high voltage and which is variably set to at least two values based on the high voltage at the operating time, and a equalizer circuit connected to the booster circuit and regulator circuit, for short-circuiting an output node of the booster circuit and an output node of the regulator circuit in response to a first control signal, wherein the operative period of the regulator circuit and the short-circuiting operation period of the equalizer circuit do not overlap each other.
    Type: Application
    Filed: June 19, 2003
    Publication date: November 13, 2003
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Toru Tanzawa, Takeshi Miyaba, Shigeru Atsumi