Patents by Inventor Ryu Ogiwara

Ryu Ogiwara 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: 8134855
    Abstract: A driver circuit and a precharge circuit apply, in a test mode, a fixed potential to a bit-line, while applying a second plate-line voltage to a plate-line. Then, the bit-line is switched from a first bit-line precharge potential to a floating state, and the plate-line voltage is raised from the second plate-line voltage to a plate-line voltage.
    Type: Grant
    Filed: March 13, 2009
    Date of Patent: March 13, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Publication number: 20120057405
    Abstract: According to one embodiment, a semiconductor memory device comprises a cell array, voltage generation circuits, and a control circuit. The cell array comprises memory cell strings. The voltage generation circuits are arranged below the cell array. Each of the memory cell strings comprises a semiconductor layer, control gates, and memory cell transistors. The semiconductor layer comprises a pair of pillar portions, and a connecting portion. The control gates intersect the pillar portion. The memory cell transistors are formed at intersections of the pillar portion and the control gates. In a write operation and a read operation, the control circuit does not drive voltage generation circuits which give noise to memory cell strings as a write target and a read target, and drives voltage generation circuits which do not give noise to the memory cell strings as the write target and the read target.
    Type: Application
    Filed: August 2, 2011
    Publication date: March 8, 2012
    Inventors: Ryu Ogiwara, Hitoshi Iwai, Kiyotaro Itagaki
  • Patent number: 8045357
    Abstract: A memory includes a memory cell array including destructive read-out type memory cells; a decoder selecting a cell; a sense amplifier configured to detect the data; and a read and write controller controlling a read operation and a write operation, wherein the read and write controller outputs a logical value of a write enable signal at the start of the read operation in a first period and makes the write enable signal invalid after the read operation starts during the first period, on the basis of the write enable signal and a restore signal keeping an activated state during the first period, the write enable signal being a signal allowing the write operation, the first period being a period from when the read operation starts to when a restore operation for writing the data back to the memory cell is completed.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: October 25, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 8045358
    Abstract: According to an aspect of the present invention, there is provided a nonvolatile semiconductor memory device including: a memory cell array including: memory cell blocks each having series-connected memory cells; wordlines; and a bitline pair connected to the memory cell blocks, one functioning as a readout bitline, the other one functioning as a reference bitline; an amplification circuit connected to the bitline pair to amplify a signal difference therebetween; and a reference voltage generation circuit including: a dummy memory cell block that has the same configuration as the memory cell block, that has one terminal connected to a first dummy plate line and that has the other terminal connected to the reference bitline; and a paraelectric capacitor that has one terminal connected to a second dummy plate line and that has the other terminal connected to the reference bitline.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: October 25, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7902913
    Abstract: According to an aspect of the present invention, there is provided a reference voltage generation circuit including: a first transistor having a first gate, a first source and a first drain; a second transistor having a second gate connected to the first gate, a second source connected to the first source and a second drain; a first diode connected between a ground and a V? node; a first resistor connected between the V? node and the first drain; a second diode and a second resistor connected between the ground and a V+ node; a third resistor connected between the V+ node and the first drain; an operational amplifier including input ports connected to the V+ node and the V? node and an output port connected to the first gate and the second gate; and a fourth resistor connected between the ground and the second drain.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: March 8, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Publication number: 20110007579
    Abstract: An internal voltage generator according to an embodiment generates a reference voltage used for detecting data stored in a semiconductor memory. A first AD converter is configured to convert an external voltage supplied to the semiconductor memory into a first digital value. A second AD converter is configured to convert a temperature characteristic voltage that changes depending on a temperature of the semiconductor memory into a second digital value. An adder is configured to receive a reference voltage trimming address that specifies the reference voltage, the first digital value, and the second digital value, and to output a third digital value obtained by performing a weighted addition of the reference voltage trimming address, the first digital value, and the second digital value. A driver is configured to output the reference voltage responding to the third digital value.
    Type: Application
    Filed: July 13, 2010
    Publication date: January 13, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA
  • Patent number: 7852142
    Abstract: An amplifying circuit receives an output from a comparator. The output is provided to each gate of first, second and third transistors. First and second resistors are connected in series. The first and second resistors and a first diode are connected to a drain of the first transistor. Second diodes are connected in parallel. The second diodes are connected to one end of a third resistor. The other end of the third resistor is connected to a drain of the second transistor. Fourth and fifth resistors are connected in series. One end of the fourth resistor is connected to the drain of the second transistor. The comparator receives first and second feedback voltages respectively obtained from a connection node between the first and second resistors and a connection node between the fourth and fifth resistors. A drain of the third transistor outputs a reference voltage.
    Type: Grant
    Filed: October 13, 2008
    Date of Patent: December 14, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7834682
    Abstract: According to an aspect of the present invention, there is provided a reference voltage generation circuit including: a first circuit configured to generate a first voltage that is independent of a power supply voltage and that is dependent of a temperature; a second circuit configured to generate a second voltage that is independent of the power supply voltage and that is dependent of the temperature; and a third circuit configured to compare the first voltage and the second voltage and to generate a reference voltage based on a higher one therebetween.
    Type: Grant
    Filed: August 6, 2008
    Date of Patent: November 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7816976
    Abstract: A power supply circuit is disclosed. The power supply circuit is provided with a reference voltage generation circuit to receive a voltage from a higher voltage supply so as to generate a reference voltage. The reference voltage from the reference voltage generation circuit is outputted to a power supply voltage generation circuit. The power supply voltage generation circuit boosts the reference voltage to generate a boosted power supply voltage. The boosted power supply voltage is inputted to a bandgap reference circuit. The bandgap reference circuit generates a reference voltage by using the boosted power supply voltage.
    Type: Grant
    Filed: October 14, 2008
    Date of Patent: October 19, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Publication number: 20100237931
    Abstract: An internal power supply voltage generation circuit 100 has a first charge pump circuit which steps up the external power supply voltage in response to the first clock signal and outputs a first stepped up voltage from the first voltage stepup output terminal; a second charge pump circuit which steps up the first stepup voltage in response to the second clock signal and outputs a second stepped up voltage from the second voltage stepup output terminal, the second stepped up voltage being higher than the first stepped up voltage; a first voltage stepdown circuit which steps down the first stepped up voltage and outputs a first stepped down voltage; and a second voltage stepdown circuit which steps down the second stepped up voltage and outputs a second stepped down voltage, the second stepped down voltage being higher than the first stepped up voltage.
    Type: Application
    Filed: March 18, 2010
    Publication date: September 23, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA
  • Publication number: 20100237933
    Abstract: A current supply circuit according to an embodiment of the present invention includes an operational amplifier having first and second input terminals and an output terminal, a transistor having a control terminal connected to the output terminal of the operational amplifier, and having first and second main terminals, a first resistance arranged between the first input terminal of the operational amplifier and the first main terminal of the transistor, a second resistance arranged between a predetermined node and a ground line, the predetermined node being between the first input terminal of the operational amplifier and the first resistance, first to Nth transistors, each of which has a control terminal connected to the control terminal or the second main terminal of the transistor, and has a main terminal outputting a current, where N is an integer of two or larger, and first to Nth switching transistors, each of which has a main terminal, the main terminals of the first to Nth switching transistors being
    Type: Application
    Filed: March 22, 2010
    Publication date: September 23, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi HIOKA, Ryu OGIWARA, Daisaburo TAKASHIMA
  • Patent number: 7795953
    Abstract: According to an aspect of the present invention, there is provided a voltage step-down circuit including: a first NMOS connected between an external and an internal power-supply voltages through a PMOS turned ON during an active state and turned OFF during a standby state; a second NMOS connected between the external and the internal power-supply voltages; and a current control circuit that sinks a current from the internal power-supply voltage to a ground level for a certain period of time after an operation state is switched from the active state to the standby state.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: September 14, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Shinichiro Shiratake, Daisaburo Takashima
  • Patent number: 7763991
    Abstract: A voltage generating circuit comprising: a switching device which includes a first end connected to a high potential side power source, and which becomes conductive in a first mode and becomes non-conductive in a second mode; a first transistor including a first main electrode connected to a second end of the switching device, a second main electrode connected to an output terminal, and a gate connected to a gate potential supply node; a second transistor including a first main electrode connected to the high potential side power source, a second main electrode connected to the output terminal, and a gate connected to the gate potential supply node; and a gate voltage stabilizing circuit that suppresses a fluctuation in potential of the potential supply node, the fluctuation accompanying a change between the first and second modes.
    Type: Grant
    Filed: November 6, 2008
    Date of Patent: July 27, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7759928
    Abstract: According to an aspect of the invention, there is provided, a semiconductor device, including an internal voltage generation circuit generating a prescribed voltage, a first test circuit connecting to a voltage-supplying wiring, one end of the voltage-supplying wiring being connected to a source wiring and the other end of the voltage-supplying wiring being connected to the internal voltage generation circuit, the first test circuit being supplied an outer voltage from the source wiring and a voltage of the internal voltage generation circuit through the voltage-supplying wiring, the first test circuit generating a prescribed resistance value on a basis of a control input from an outer portion in a test mode.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: July 20, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7750723
    Abstract: According to an aspect of the present invention, there is provided a voltage generation circuit including: first and second reference terminals to output first and second reference voltages, respectively; first PMOS and first NMOS transistors connected between high and low level power supply lines in series; an output terminal connected between the first PMOS and first NMOS transistors; a first operational amplifier including: first input terminals each including a gate of a PMOS transistor to be connected to one of the second reference terminal and the output terminal, and a first output terminal connected to the first PMOS transistor; and a second operational amplifier including: second input terminals each including a gate of an NMOS transistor to be connected to one of the first reference terminal and the output terminal, and a second output terminal connected to the first NMOS transistor.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: July 6, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Patent number: 7746164
    Abstract: Disclosed is a voltage generating circuit which steps down a voltage to output a stepped down voltage. The voltage generating circuit includes first and second transistors. The drains of the first and second transistors are connected to a higher voltage power supply. The gate of the first transistor is connected to the gate of the second transistor. The voltage of the gate of the first transistor is controlled by a control circuit such that a voltage of the source of the first transistor can reach a predetermined voltage. A stepped down voltage is outputted from the source of the second transistor.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: June 29, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Daisaburo Takashima
  • Publication number: 20100149850
    Abstract: According to an aspect of the present invention, there is provided a nonvolatile semiconductor memory device including: a memory cell array including: memory cell blocks each having series-connected memory cells; wordlines; and a bitline pair connected to the memory cell blocks, one functioning as a readout bitline, the other one functioning as a reference bitline; an amplification circuit connected to the bitline pair to amplify a signal difference therebetween; and a reference voltage generation circuit including: a dummy memory cell block that has the same configuration as the memory cell block, that has one terminal connected to a first dummy plate line and that has the other terminal connected to the reference bitline; and a paraelectric capacitor that has one terminal connected to a second dummy plate line and that has the other terminal connected to the reference bitline.
    Type: Application
    Filed: December 10, 2009
    Publication date: June 17, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA
  • Patent number: 7733683
    Abstract: Disclosed is a semiconductor memory including ferroelectric capacitors. Memory cells each including a ferroelectric capacitor and an insulted-gate-type cell transistor are connected to a corresponding one of bit lines. Insulated-gate-type separating transistors are connected between multiple bit-line selecting transistors and multiple sense amplifiers, respectively. When the separating transistors are turned on, data retained in the sense amplifiers are capable of being written to the memory cells during the same time period substantially.
    Type: Grant
    Filed: January 3, 2008
    Date of Patent: June 8, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisaburo Takashima, Ryu Ogiwara
  • Patent number: 7724581
    Abstract: A discharge order control circuit includes a pool circuit a delay circuit and a discharge unit to control a discharge order of internal power supplies. The pool circuit stores electric charges provided from a potential of an external power supply. The delay circuit operates on the electric charges stored in the pool circuit and delays a discharge signal generated when potential of the external power supply is lowered to a predetermined potential level. The delay circuit includes an inverter array having a plurality of stages each containing an inverter. The plurality of stages include a final stage that outputs the delayed discharge signal. Only the inverter of the final stage generates an RC delay.
    Type: Grant
    Filed: February 5, 2007
    Date of Patent: May 25, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryu Ogiwara, Shinichiro Shiratake, Daisaburo Takashima
  • Publication number: 20100090727
    Abstract: A voltage detection circuit of the present invention includes an NMOS transistor diode-connected, a gate and a drain thereof being supplied with a power supply voltage, a resistor connected between a source of the NMOS transistor and a ground potential, and a source voltage detection circuit receiving a voltage of the source, wherein an NMOS type transistor is employed as the NMOS transistor, a channel width and a channel length of the NMOS type transistor being set in such a manner that an operating point on a VG-ID curve of the NMOS type transistor may come to a certain point, at the certain point, a drain current of the NMOS type transistor being constant even if the temperature fluctuates.
    Type: Application
    Filed: September 21, 2009
    Publication date: April 15, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryu Ogiwara, Daisaburo Takashima