Patents by Inventor Hiroki Fujisawa

Hiroki Fujisawa 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: 9570122
    Abstract: A device includes a first data terminal, a second data terminal, a first switching buffer coupled between a data node and the first data terminal and a second switching buffer coupled between the data node and the second data terminal. The first switching buffer and the second switching buffer are arranged such that a distance between the first switching buffer and the second data terminal is shorter than a distance between the second switching buffer and the second data terminal and that a distance between the first switching buffer and the first data terminal is shorter than a distance between the second switching buffer and the first data terminal.
    Type: Grant
    Filed: March 11, 2015
    Date of Patent: February 14, 2017
    Assignee: Micron Technology, Inc.
    Inventor: Hiroki Fujisawa
  • Patent number: 9570119
    Abstract: A method for controlling termination impedance of a data terminal in a dynamic random access memory device includes receiving a mode register set command to set an operation mode to a first mode, setting the operation mode in a mode register to the first mode, receiving a self-refresh entry command, entering self-refresh mode, activating a first input buffer connected to a termination impedance control terminal, and receiving an impedance control signal at the first buffer, wherein the termination impedance of the data terminal is set to a first impedance value if the termination impedance control signal has a first level and the termination impedance of the data terminal is set to a second impedance value if the termination impedance control signal has a second level.
    Type: Grant
    Filed: August 4, 2014
    Date of Patent: February 14, 2017
    Assignee: LONGITUDE SEMICONDUCTOR S.A.R.L.
    Inventor: Hiroki Fujisawa
  • Patent number: 9530459
    Abstract: A semiconductor memory disclosed in this disclosure includes first and second memory cell arrays, a first main data line that transfers the read data read from the first memory cell array, a second main data line that transfers the read data read from the second memory cell array, a main amplifier coupled to the second main data line, and a repeater circuit coupled to the first main data line and the second main data line.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: December 27, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Shingo Mitsubori, Hiroki Fujisawa
  • Publication number: 20160359484
    Abstract: To decrease the circuit scale necessary for the calibration of the output circuit and to decrease the time required for the calibration operation. The invention includes a first output buffer and a second output buffer that are connected to a data pin, and a calibration circuit that is connected to a calibration pin. The first output buffer and the second output buffer include plural unit buffers. The unit buffers have mutually the same circuit structures. With this arrangement, the impedances of the first output buffer and the second output buffer can be set in common, based on the calibration operation using the calibration circuit. Consequently, both the circuit scale necessary for the calibration operation and the time required for the calibration operation can be decreased.
    Type: Application
    Filed: June 9, 2016
    Publication date: December 8, 2016
    Applicant: PS4 Luxco S.a.r.l.
    Inventor: Hiroki Fujisawa
  • Patent number: 9473146
    Abstract: Apparatuses and methods for low power counting circuits are described herein. An example apparatus may include a frequency divider configured to receive an input clock signal and adjust a frequency of the clock signal to provide an intermediate clock signal. The apparatus may further include a counter coupled to the frequency divider and configured to receive the intermediate clock signal. The counter may further be configured to provide a plurality of timing signals based on the intermediate clock signal. The apparatus may further include a frequency multiplier including a plurality of logic gates. Each of the plurality of logic gates may be coupled to the counter and configured to receive a respective first timing signal of the plurality of timing signals and at least one of the intermediate clock signal or a respective second timing signal of the plurality of timing signals.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: October 18, 2016
    Assignee: Micron Technology, Inc.
    Inventor: Hiroki Fujisawa
  • Publication number: 20160226495
    Abstract: Apparatuses and methods for low power counting circuits are described herein. An example apparatus may include a frequency divider configured to receive an input clock signal and adjust a frequency of the clock signal to provide an intermediate clock signal. The apparatus may further include a counter coupled to the frequency divider and configured to receive the intermediate clock signal. The counter may further be configured to provide a plurality of timing signals based on the intermediate clock signal. The apparatus may further include a frequency multiplier including a plurality of logic gates. Each of the plurality of logic gates may be coupled to the counter and configured to receive a respective first timing signal of the plurality of timing signals and at least one of the intermediate clock signal or a respective second timing signal of the plurality of timing signals.
    Type: Application
    Filed: February 3, 2015
    Publication date: August 4, 2016
    Inventor: HIROKI FUJISAWA
  • Patent number: 9406606
    Abstract: A device includes a first power supply line supplying a first voltage, first, second, and third nodes, a selection circuit connected between the first power supply line and the first node, a first anti-fuse connected between the first node and the second node, and a second anti-fuse connected between the first node and the third node. The second node and the third node are not connected to each other.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: August 2, 2016
    Assignee: Micron Technology, Inc.
    Inventor: Hiroki Fujisawa
  • Patent number: 9391612
    Abstract: To decrease the circuit scale necessary for the calibration of the output circuit and to decrease the time required for the calibration operation. The invention includes a first output buffer and a second output buffer that are connected to a data pin, and a calibration circuit that is connected to a calibration pin. The first output buffer and the second output buffer include plural unit buffers. The unit buffers have mutually the same circuit structures. With this arrangement, the impedances of the first output buffer and the second output buffer can be set in common, based on the calibration operation using the calibration circuit. Consequently, both the circuit scale necessary for the calibration operation and the time required for the calibration operation can be decreased.
    Type: Grant
    Filed: June 1, 2015
    Date of Patent: July 12, 2016
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Hiroki Fujisawa
  • Patent number: 9378799
    Abstract: A semiconductor device having a circuit that selectively adjusts an impedance of an output buffer. A calibration operation can be performed automatically without issuing a calibration command from a controller. Because a calibration operation to a memory is performed in response to an auto refresh command having been issued for a predetermined number of times, a periodic calibration operation can be secured, and a read operation or a write operation is not requested from a controller during a calibration operation. A start-up circuit activates the calibration circuit when a refresh counter indicates a predetermined value, and prohibits a refresh operation in response to the auto refresh command when the calibration circuit is activated. A temperature detecting circuit may be used to change the frequency of performing a calibration operation.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: June 28, 2016
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Nakaba Kaiwa, Yutaka Ikeda, Hiroki Fujisawa, Tetsuaki Okahiro
  • Patent number: 9336856
    Abstract: A device includes a plurality of input terminals, a control circuit, and a plurality of signal buses. Each of the signal buses is coupled between the control circuit and an associated one of the plurality of input terminals and includes one or more first buffers, one or more second buffers and at least one latch circuit coupled between the one or more first buffers and the one or more second buffers. The one or more first buffers of one of the signal buses are different in number from the one or more first buffers of a different one of the signal buses.
    Type: Grant
    Filed: March 4, 2015
    Date of Patent: May 10, 2016
    Assignee: Micron Technology, Inc.
    Inventors: Hiroto Kinoshita, Hiroki Fujisawa
  • Patent number: 9224451
    Abstract: A method for operating a dynamic random access memory device includes providing a clock signal to a clock terminal of the dynamic random access memory device, selecting one of a first operating mode and a second operating mode of the dynamic random access memory device, the first operating mode, when selected, corresponding to the DRAM periodically refreshing a first number of word lines, and the second operating mode, when selected, corresponding to the DRAM periodically refreshing a second number of word lines different from the first number, and providing a self-refresh command to a command terminal of the dynamic random access memory device.
    Type: Grant
    Filed: April 2, 2014
    Date of Patent: December 29, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Hiroki Fujisawa
  • Patent number: 9196349
    Abstract: A device includes an output circuit, a DLL (Delay Locked Loop) circuit including a first delay line receiving a first clock signal and outputting, in response to receiving the clock signal, a second clock signal supplied to the output circuit, and an ODT (On Die Termination) circuit receiving an ODT activation signal and outputting, in response to receiving the ODT activation signal, an ODT output signal supplied to the output circuit to set the output circuit in a resistance termination state, and the ODT circuit including a second delay line configured to be set by the DLL circuit in an equivalent delay amount that is equivalent to a delay amount of the first delay line, the ODT output signal being, in a first time-period during which the ODT activation signal is in an active state, generated by being conveyed via the second delay line in which the equivalent delay amount has been set.
    Type: Grant
    Filed: July 25, 2014
    Date of Patent: November 24, 2015
    Assignee: MICRON TECHNOLOGY, INC.
    Inventors: Kazutaka Miyano, Hiroki Fujisawa
  • Publication number: 20150269985
    Abstract: A semiconductor device having a circuit that selectively adjusts an impedance of an output buffer. A calibration operation can be performed automatically without issuing a calibration command from a controller. Because a calibration operation to a memory is performed in response to an auto refresh command having been issued for a predetermined number of times, a periodic calibration operation can be secured, and a read operation or a write operation is not requested from a controller during a calibration operation. A start-up circuit activates the calibration circuit when a refresh counter indicates a predetermined value, and prohibits a refresh operation in response to the auto refresh command when the calibration circuit is activated. A temperature detecting circuit may be used to change the frequency of performing a calibration operation.
    Type: Application
    Filed: May 22, 2015
    Publication date: September 24, 2015
    Inventors: Nakaba Kaiwa, Yutaka Ikeda, Hiroki Fujisawa, Tetsuaki Okahiro
  • Publication number: 20150269986
    Abstract: A device includes a first data terminal, a second data terminal, a first switching buffer coupled between a data node and the first data terminal and a second switching buffer coupled between the data node and the second data terminal. The first switching buffer and the second switching buffer are arranged such that a distance between the first switching buffer and the second data terminal is shorter than a distance between the second switching buffer and the second data terminal and that a distance between the first switching buffer and the first data terminal is shorter than a distance between the second switching buffer and the first data terminal.
    Type: Application
    Filed: March 11, 2015
    Publication date: September 24, 2015
    Inventor: HIROKI FUJISAWA
  • Patent number: 9142276
    Abstract: For example, a semiconductor device includes a first latency counter, which selects whether to give an odd-cycle latency to an internal command signal; and a second latency counter, which gives a latency to an internal command signal at intervals of two cycles. The latency counters are connected in series. Since the number of bits in control information, which is used to set a latency, is smaller than the types of settable latency as a result, it is possible to reduce wiring density.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: September 22, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventor: Hiroki Fujisawa
  • Publication number: 20150263727
    Abstract: To decrease the circuit scale necessary for the calibration of the output circuit and to decrease the time required for the calibration operation. The invention includes a first output buffer and a second output buffer that are connected to a data pin, and a calibration circuit that is connected to a calibration pin. The first output buffer and the second output buffer include plural unit buffers. The unit buffers have mutually the same circuit structures. With this arrangement, the impedances of the first output buffer and the second output buffer can be set in common, based on the calibration operation using the calibration circuit. Consequently, both the circuit scale necessary for the calibration operation and the time required for the calibration operation can be decreased.
    Type: Application
    Filed: June 1, 2015
    Publication date: September 17, 2015
    Applicant: PS4 Luxco S.a.r.l.
    Inventor: Hiroki Fujisawa
  • Publication number: 20150255145
    Abstract: A device includes a plurality of input terminals, a control circuit, and a plurality of signal buses. Each of the signal buses is coupled between the control circuit and an associated one of the plurality of input terminals and includes one or more first buffers, one or more second buffers and at least one latch circuit coupled between the one or more first buffers and the one or more second buffers. The one or more first buffers of one of the signal buses are different in number from the one or more first buffers of a different one of the signal buses.
    Type: Application
    Filed: March 4, 2015
    Publication date: September 10, 2015
    Inventors: Hiroto Kinoshita, Hiroki Fujisawa
  • Publication number: 20150235680
    Abstract: An apparatus includes a first terminal configured to communicate data with an outside of the apparatus, a second terminal configured to receive a first power source potential, a third terminal configured to receive a second power source potential lower than the first power source potential, a fourth terminal configured to be coupled to a calibration resistor, an output buffer including first to third nodes coupled to the first to third terminals respectively, and a replica circuit including fourth and fifth nodes coupled to the second and third terminals respectively, and sixth node coupled to the fourth terminal.
    Type: Application
    Filed: February 13, 2015
    Publication date: August 20, 2015
    Inventors: Hiromasa Takeda, Hiroki Fujisawa
  • Patent number: 9047986
    Abstract: To decrease the circuit scale necessary for the calibration of the output circuit and to decrease the time required for the calibration operation. The invention includes a first output buffer and a second output buffer that are connected to a data pin, and a calibration circuit that is connected to a calibration pin. The first output buffer and the second output buffer include plural unit buffers. The unit buffers have mutually the same circuit structures. With this arrangement, the impedances of the first output buffer and the second output buffer can be set in common, based on the calibration operation using the calibration circuit. Consequently, both the circuit scale necessary for the calibration operation and the time required for the calibration operation can be decreased.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: June 2, 2015
    Assignee: PS4 LUXCO S.A.R.L.
    Inventor: Hiroki Fujisawa
  • Patent number: 9041436
    Abstract: To reduce power supply noises occurring in a control circuit unit for controlling an output buffer. A semiconductor device includes unit buffers for driving a data output terminal, impedance control circuits for controlling the unit buffers, and a control circuit unit for controlling the impedance control circuits. The impedance control circuits and the control circuit unit operate by mutually-different power supplies, the control circuit unit supplies pull-up data and pull-down data in mutually reverse phase to the impedance control circuits, and the impedance control circuits convert the pull-up data and the pull-down data from reverse phase to in-phase and supply the same to the unit buffers. Thereby, a noise is difficult to occur in a power supply VDD used for the control circuit unit.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: May 26, 2015
    Assignee: PS4 Luxco S.a.r.l.
    Inventors: Shunji Kuwahara, Hiroki Fujisawa