Temperature Compensation Patents (Class 365/211)
  • Patent number: 7646661
    Abstract: A self-refresh control circuit includes a first constant current generating circuit that generates a constant current to change depending on the temperature, a second constant current generating circuit to generate a constant current not depending on the temperature, a current-cycle converting circuit selectively connected to the first constant current generating circuit and the second constant current generating circuit and converting the constant currents inputted from the first constant current generating circuit and the second constant current generating circuit into a test refresh cycle used for setting the refresh cycle.
    Type: Grant
    Filed: February 6, 2008
    Date of Patent: January 12, 2010
    Assignee: NEC Electronics Corporation
    Inventors: Hiroki Koga, Kazutaka Taniguchi
  • Publication number: 20090323400
    Abstract: There is provided a technique for ensuring both an SNM and a write margin simultaneously in a semiconductor device having static memory cells. A semiconductor device has a plurality of static memory cells. The semiconductor device includes a memory cell array having the static memory cells arranged in a matrix, a temperature sensor circuit for sensing a temperature in the semiconductor device, and a word driver for controlling a voltage supplied to a word line of the memory cell array based on an output of the temperature sensor circuit at the time of writing to or reading from a memory cell.
    Type: Application
    Filed: April 30, 2009
    Publication date: December 31, 2009
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventor: Masao SHINOZAKI
  • Patent number: 7639548
    Abstract: A semiconductor device that may include temperature sensing circuits is disclosed. The temperature sensing circuits may be used to control various parameters, such as internal regulated supply voltages, internal refresh frequency, a word line low voltage, or the like. In this way, operating specifications of a semiconductor device at worst case temperatures may be met without compromising performance at normal operating temperatures. Each temperature sensing circuit may include a selectable temperature threshold value as well as a selectable temperature hysteresis value. In this way, temperature performance characteristics may be finely tuned. Furthermore, a method of testing the temperature sensing circuits is disclosed in which a current value may be monitored and temperature threshold values and temperature hysteresis values may be thereby determined.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: December 29, 2009
    Inventor: Darryl G. Walker
  • Patent number: 7630265
    Abstract: A temperature invariant reference voltage and a temperature variant physical quantity, such as a voltage or current, are generated. The temperature variant physical quantity changes in response to a temperature of the integrated circuit. A temperature sensor circuit generates a voltage that is linearly dependent on the temperature. A level generator circuit generates 2n?1 voltage levels from the reference voltage. A comparator circuit, such as an analog-to-digital circuit, compares the voltage from the temperature sensor to the 2n?1 voltage levels to determine which level is closest. An n-bit digital output of the resulting level is proportional to the temperature of the integrated circuit.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: December 8, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Agostino Macerola, Giulio-Giuseppe Marotta, Marco-Domenico Tiburzi
  • Patent number: 7630266
    Abstract: A temperature sensor generates a digital representation of the temperature of the integrated circuit. A logic circuit reads the digital temperature and generates a multiple bit digital representation of an operational voltage and a multiple bit digital representation of a timing signal, both being functions of the integrated circuit temperature. A voltage generator converts the digital representation of the operational voltage to an analog voltage that biases portions of the integrated circuit requiring temperature compensated voltages. In one embodiment, the temperature compensated voltages bias memory cells. A timing generator converts the multiple bit digital representation of the timing signal to a logic signal.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: December 8, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Michele Incarnati, Giovanni Santin
  • Patent number: 7630267
    Abstract: A temperature detector in an integrated circuit comprises a temperature-dependent voltage generator, a ring oscillator, a timer and a clock-driven recorder. The temperature-dependent voltage generator is configured to generate at least one temperature-dependent voltage. The ring oscillator is configured to generate a clock signal, which is affected by one of the at least one temperature-dependent voltage. The timer is configured to generate a time-out signal, which is affected by one of the temperature-dependent voltage. The clock-driven recorder has a clock input terminal in response to the clock signal and time-out signal.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: December 8, 2009
    Assignee: Elite Semiconductor Memory Technology Inc.
    Inventor: Chung Zen Chen
  • Publication number: 20090290432
    Abstract: A method of reading data in a non-volatile memory device compensates for a change in a reading/verifying result in accordance with a change of temperature. The method includes sensing a temperature of memory cells, setting a first voltage and a second voltage of a bit line sensing signal in accordance with the sensed temperature, precharging a bit line in accordance with the set first voltage, evaluating a change of a voltage level of the bit line based on whether a memory cell for a read operation is programmed, and sensing data of the memory cell in accordance with the set second voltage. The method may read/verify data constantly even though a temperature is changed.
    Type: Application
    Filed: June 28, 2008
    Publication date: November 26, 2009
    Applicant: Hynix Semiconductor Inc.
    Inventor: Jin Su PARK
  • Publication number: 20090290428
    Abstract: A verification reference voltage supply unit includes a reference voltage supply unit, a temperature-dependent voltage supply unit, and an amplification unit. The reference voltage supply unit is configured to supply a first reference voltage and a second reference voltage, each of which is configured to maintain a constant value irrespective of a temperature variation. The temperature-dependent voltage supply unit is configured to receive the first reference voltage and generate a temperature-dependent voltage having a voltage level that increases in proportion to a temperature increase. The amplification unit is configured to amplify the temperature-dependent voltage and the second reference voltage and generate a verification reference voltage.
    Type: Application
    Filed: May 19, 2009
    Publication date: November 26, 2009
    Inventor: Yu Jong NOH
  • Patent number: 7619940
    Abstract: An apparatus for generating a power up signal for a semiconductor memory chip includes a temperature information providing unit that outputs a control voltage corresponding to predetermined temperature information. A power up signal generating unit generates the power up signal based at least on one of an external voltage or the control voltage.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: November 17, 2009
    Assignee: Hynix Semiconductor Inc.
    Inventor: Gyo-Soo Chu
  • Patent number: 7619936
    Abstract: One embodiment of the present invention provides a system including a tester and a back end manufacturing system. The tester tests a resistive memory and obtains configuration data for the resistive memory. The back end manufacturing system prevents temperatures in back end processing from reducing data retention time of the configuration data in the resistive memory.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: November 17, 2009
    Assignee: Qimonda North America Corp.
    Inventors: Jan Boris Philipp, Thomas Happ
  • Publication number: 20090268509
    Abstract: A nonvolatile semiconductor memory device comprises a memory cell array including first and second mutually crossing lines and electrically erasable programmable memory cells arranged at intersections of the first and second lines, each memory cell containing a variable resistor operative to nonvolatilely store the resistance thereof as data and a first non-ohmic element operative to switch the variable resistor; and a clamp voltage generator circuit operative to generate a clamp voltage required for access to the memory cell and applied to the first and second lines. The clamp voltage generator circuit has a temperature compensation function of compensating for the temperature characteristic of the first non-ohmic element.
    Type: Application
    Filed: March 24, 2009
    Publication date: October 29, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Hiroshi MAEJIMA
  • Patent number: 7609195
    Abstract: An on die thermal sensor (ODTS) in a memory device includes: a band gap unit for detecting a temperature of the memory device to output a first voltage corresponding to the temperature; and an analog-to-digital converting unit for outputting a digital code having temperature information based on the first voltage, the digital code having varied resolution according to temperature ranges.
    Type: Grant
    Filed: December 31, 2007
    Date of Patent: October 27, 2009
    Assignee: Hynix Semiconductor, Inc.
    Inventor: Chun-Seok Jeong
  • Publication number: 20090262593
    Abstract: A circuit comprises at least one memory cell adapted to store data in terms of values of an electrical characteristic thereof, which exhibits a variability with temperature according to a first variation law; a voltage generator is provided for generating a voltage to be supplied to the at least one memory cell for retrieving the data stored therein, the voltage generator including first means adapted to cause the generated voltage take a value in a set of target values including at least one target value, corresponding to an operation to be performed on the memory cell. The voltage generator comprises second means for causing the value taken by the generated voltage vary with temperature according to a prescribed second variation law exploiting a compensation circuit element having said electrical characteristic.
    Type: Application
    Filed: October 9, 2008
    Publication date: October 22, 2009
    Inventors: Luca Crippa, Giancarlo Ragone, Miriam Sangalli, Rino Micheloni
  • Patent number: 7606099
    Abstract: A semiconductor memory device controlling an output voltage level of a high voltage generator in response to a variation of temperature has a high voltage generator that provides a high voltage higher than a power source voltage through an output terminal, generates a temperature detection signal obtained by sensing a variation of a diode current based on a temperature variation, and adjusts a voltage level of the output terminal in response to the temperature detection signal. The device is able to automatically control an output voltage or current of the high voltage generator.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: October 20, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hwi-Taek Chung
  • Publication number: 20090251947
    Abstract: A semiconductor device has a DRAM cell configured from an information charge accumulating capacitor and a memory cell selecting transistor, the threshold voltage value of a MOS transistor that constitutes a sense circuit is monitored, and the monitored threshold voltage value of the MOS transistor is converted through the use of a transfer ratio that is determined based on the capacitance of the information charge accumulating capacitor and the parasitic capacitance of the bit line. The converted voltage value is level-shifted so that the pre-charge voltage of a pre-charge circuit is a pre-set voltage, a current feeding capability is added to the level-shifted voltage value, and the voltage is fed as the pre-charge voltage.
    Type: Application
    Filed: March 17, 2009
    Publication date: October 8, 2009
    Applicant: Elpida Memory, Inc.
    Inventor: Kazuhiko Kajigaya
  • Publication number: 20090245003
    Abstract: A semiconductor memory device is provided which comprises: a sense amplifier; and a bit line, wherein the disconnection of the sense amplifier from the bit line is performed in a data read operation when temperature in the semiconductor memory device is at a first temperature, and wherein the disconnection of the sense amplifier from the bit line is not performed in the data read operation when the temperature in the semiconductor memory device is at a second temperature.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 1, 2009
    Applicant: FUJITSU MICROELECTRONICS LIMITED
    Inventor: Shigemasa ITO
  • Patent number: 7593278
    Abstract: A memory element comprises an addressable memory cell. A thermoelectric device couples to the memory cell. Electrical conductors provide a current pulse to the thermoelectric device. The current pulse generates a thermoelectric heat flow pulse between the thermoelectric device and the memory cell.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: September 22, 2009
    Assignee: Seagate Technology LLC
    Inventors: Yufeng Hu, Michael Seigler, Kalman Pelhos
  • Publication number: 20090231936
    Abstract: A memory device has data transceivers, write strobe transceivers, and read strobe transceivers. The data transceivers transfer input data to the memory device and transfer output data from the memory device. The write strobe transceivers transfer timing information of the input data. The read strobe transceivers transfer timing information of the output data. The memory device also has an auxiliary circuit for generating auxiliary information. The auxiliary information includes information different from the timing information of the input data and the output data. The auxiliary circuit uses the write and read transceivers to transfer the auxiliary information to and from the memory device.
    Type: Application
    Filed: March 3, 2009
    Publication date: September 17, 2009
    Inventors: Joo S. Choi, Troy A. Manning
  • Publication number: 20090225590
    Abstract: Provided is a phase change random access (PRAM) memory. The PRAM may include a memory cell array having a plurality of phase change memory cells, and a data read circuit including a compensation unit and a sense amplifier, the compensation unit configured to provide a sensing node with a compensation current to compensate for a decrease in a level of the sensing node caused by a current flowing through one of the plurality of phase change memory cells, and the sense amplifier configured to compare a level of the sensing node with a reference level and output a result of the comparison.
    Type: Application
    Filed: May 11, 2009
    Publication date: September 10, 2009
    Inventors: Hyung-rok Oh, Woo-Yeong Cho, Beak-hyung Cho
  • Patent number: 7583539
    Abstract: A non-volatile storage system in which a body bias is applied to a non-volatile storage system to compensate for temperature-dependent variations in threshold voltage, sub-threshold slope, depletion layer width and/or 1/f noise. A desired bias level is set based on a temperature-dependent reference signal. In one approach, a level of the biasing can decrease as temperature increases. The body bias can be applied by applying a voltage to a p-well and n-well of a substrate, applying a voltage to the p-well while grounding the n-well, or grounding the body and applying a voltage to the source and/or drain of a set of non-volatile storage elements. Further, temperature-independent and/or temperature-dependent voltages can be applied to selected and unselected word lines in the non-volatile storage system during program, read or verify operations. The temperature-dependent voltages can vary based on different temperature coefficients.
    Type: Grant
    Filed: December 30, 2006
    Date of Patent: September 1, 2009
    Assignee: SanDisk Corporation
    Inventors: Deepak Chandra Sekar, Nima Mokhlesi
  • Publication number: 20090213667
    Abstract: An internal voltage generating circuit generates and supplies a boosted voltage higher than an internal power supply voltage, as an operating power supply voltage, to a sense amplifier in a read circuit for reading data of a memory cell. A bit line precharge current supplied via an internal data line is produced from the internal power supply voltage. It is possible to provide a nonvolatile semiconductor memory device, which can perform a precise sense operation and an accurate reading of data even under a low power supply voltage condition.
    Type: Application
    Filed: May 7, 2009
    Publication date: August 27, 2009
    Applicant: Renesas Technology Corporation
    Inventors: Takashi KUBO, Takashi ITOH, Yasuhiro KASHIWAZAKI, Taku OGURA, Kiyohiro FURUTANI
  • Patent number: 7580303
    Abstract: A precharge voltage generating circuit outputs any of a plurality of kinds of precharge voltages in accordance with an ambient temperature. A precharge circuit supplies the precharge voltage to a bit line during the nonaccess of a dynamic memory cell. A sense amplifier amplifies a difference between the voltage of a data signal read from the dynamic memory cell onto the bit line and the supplied precharge voltage. The precharge voltage is altered in accordance with the ambient temperature, whereby the read margin of the sense amplifier can be changed, and the worst value of the data retaining time of the memory cell can be improved. As a result, the frequency of refreshing of the memory cell can be lowered, reducing power consumption and a standby current.
    Type: Grant
    Filed: October 13, 2006
    Date of Patent: August 25, 2009
    Assignee: Fujitsu Microelectronics Limited
    Inventors: Koichi Nishimura, Shinichiro Ikemasu
  • Publication number: 20090201724
    Abstract: A device and corresponding method of using a temperature dependent bias generator to generate a voltage that is applied to a control gate of a sense amplifier is disclosed. By applying the temperature dependent bias signal to the sense amplifier, a substantially temperature independent disclosing time can be achieved at a sense node of a sense amplifier.
    Type: Application
    Filed: February 13, 2008
    Publication date: August 13, 2009
    Applicant: SPANSION LLC
    Inventor: Takao Akaogi
  • Patent number: 7557665
    Abstract: A temperature-dependent oscillator includes a first current source, wherein a first current provided by the first current source has a positive temperature coefficient, a second current source serially connected to the first current source, wherein a second current provided by the second current source has a negative temperature coefficient, and a capacitor serially connected to the first current source and parallel connected to the second current source.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: July 7, 2009
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Shine Chung, Jonathan Hung
  • Patent number: 7554869
    Abstract: A semiconductor memory device having internal circuits responsive to temperature data, in order to compensate an output characteristic change of the internal circuits and reduce power consumption depending on temperature change, and method thereof are disclosed. The semiconductor memory device may include a temperature sensing circuit and an internal circuit. The temperature sensing circuit may generate and output temperature data in response to ambient temperature of the semiconductor memory device. The internal circuit may adjust an output level of an output signal in response to the temperature data from the temperature sensing circuit.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: June 30, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Soo-Young Kim, Sang-Jae Rhee, Min-Gyu Hwang
  • Publication number: 20090161464
    Abstract: A semiconductor memory device includes a memory cell array which includes a plurality of memory cells which are arrayed in a matrix at intersections between a plurality of word lines and a plurality of bit lines and a power supply circuit which includes a first band gap reference circuit which outputs a first output voltage, and a second band gap reference circuit which outputs a second output voltage having lower temperature characteristics than the first output voltage on a low temperature side, and generates a power supply voltage on the basis of the second output voltage at a time of a data write operation of the memory cells.
    Type: Application
    Filed: December 18, 2008
    Publication date: June 25, 2009
    Inventors: Tatsuro MIDORIKAWA, Yasuhiko Honda, Gyosho Chin
  • Patent number: 7551501
    Abstract: A semiconductor memory device includes a thermosensor that senses present temperatures of the device and confirms whether the temperature values are valid. The thermosensor includes a temperature sensing unit, a storage unit and an initializing unit. The temperature sensing unit senses temperatures in response to a driving signal. The storage unit stores output signals of the temperature sensing unit and outputs temperature values. The initializing unit initializes the storage unit after a predetermined time from an activation of the driving signal. A driving method includes driving the thermosensor in response to the driving signal, requesting a re-driving after a predetermined time from the activation of the driving signal, and re-driving the thermosensor in response to the driving signal input again.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: June 23, 2009
    Assignee: Hynix Semiconductor, Inc.
    Inventors: Kyung-Hoon Kim, Patrick B. Moran
  • Patent number: 7548451
    Abstract: Provided is a phase change random access (PRAM) memory. The PRAM may include a memory cell array having a plurality of phase change memory cells, and a data read circuit including a compensation unit and a sense amplifier, the compensation unit configured to provide a sensing node with a compensation current to compensate for a decrease in a level of the sensing node caused by a current flowing through one of the plurality of phase change memory cells, and the sense amplifier configured to compare a level of the sensing node with a reference level and output a result of the comparison.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: June 16, 2009
    Assignee: Samsung Electronics, Co., Ltd.
    Inventors: Hyung-rok Oh, Woo-yeong Cho, Beak-hyung Cho
  • Patent number: 7548477
    Abstract: A method adapts circuit components of a memory module to changing operating conditions within a predefined range. According to one embodiment, a memory module provides a sensor arrangement and a communication bus. Sub-ranges are defined for at least one operating condition, in which the circuit components can work with a fixed setup. During operation, the current state of the at least one operating condition is sensed using the sensing arrangement. The sensed state of the operating condition is mapped to one of the predefined ranges and an associated set of control signals is transmitted over the communication bus. The control signals transmitted over the communication bus are used to adapt at least one circuit component to the current operating conditions.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: June 16, 2009
    Assignee: Infineon Technologies Flash GmbH & Co. KG
    Inventor: Luca de Ambroggi
  • Patent number: 7545696
    Abstract: A ferro-electric memory device suppresses deterioration of retention characteristics at the time when an ambient temperature has decreased, without requiring a much longer cycle time. The ferro-electric memory device includes a first ferro-electric capacitor for use in a first normal cell and a second ferro-electric capacitor for use in a second normal cell. The ferro-electric memory device also includes: a temperature detection circuit which detects an ambient temperature of the first and second normal cells; and a normal cell power supply switching circuit which switches a voltage to be applied to the first and second ferro-electric capacitors depending on the detected temperature.
    Type: Grant
    Filed: December 30, 2005
    Date of Patent: June 9, 2009
    Assignee: Panasonic Corporation
    Inventor: Kunisato Yamaoka
  • Patent number: 7539789
    Abstract: Memory circuits that concatenate multiple FIFOs in parallel to increase the overall depth of the memory circuits. Asymmetric input and output ports can be provided by including a deserializer on the write interface of the memory circuit and/or a serializer on the read interface of the memory circuit. The deserializer disperses the data evenly across all FIFOs, minimizing the write-to-read latency. In some embodiments, at most two of the FIFOs are active at any given time, one being written and one being read, which reduces the overall power consumption of the memory circuit compared to known structures.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: May 26, 2009
    Assignee: Xilinx, Inc.
    Inventor: James E. Ogden
  • Patent number: 7535786
    Abstract: The temperature sensing circuits may be used to control various parameters, such as internal regulated supply voltages, internal refresh frequency, a word line low voltage, or the like. In this way, operating specifications of a semiconductor device at worst case temperatures may be met without comprising performance at normal operating temperatures. Each temperature sensing circuit may include a selectable temperature threshold value as well as a selectable temperature hysteresis value. In this way, temperature performance characteristics may be finely tuned. Furthermore, a method of testing the temperature sensing circuits is disclosed in which a current value may be monitored and temperature threshold values and temperature hysteresis values may be thereby determined.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: May 19, 2009
    Inventor: Darryl Walker
  • Publication number: 20090109742
    Abstract: Systems and/or methods are presented that can facilitate regulating performance of operations in a memory device based on controlling an operating temperature slope associated with the memory device. A regulator component can facilitate controlling the operating temperature slope level and controlling a reference voltage(s) associated with a word-line(s) and/or bit-line(s) to facilitate execution of operations in a memory, while also controlling a respective current level(s) associated with the reference voltage to minimize errors in the memory or harm to the memory. The reference voltage can be controlled based on a first resistance and the current level can be controlled based on a second resistance that can be based on the first resistance. An analyzer component can facilitate determining a desired operating temperature slope level. Trim bits can be employed to facilitate setting the first resistance and/or the second resistance.
    Type: Application
    Filed: October 30, 2007
    Publication date: April 30, 2009
    Applicant: SPANSION LLC
    Inventors: Leong Mun Fook, Ang Boon Aik, Ong Mee Choo
  • Patent number: 7525860
    Abstract: A temperature control circuit, comprising: a plurality of temperature sensors each configured to measure a temperature of a corresponding memory chip chosen from a plurality of memory chips, and to generate a sensor output signal that is set to a first voltage if the measured temperature of the corresponding memory chip meets a temperature requirement, and is set to a floating voltage if the measured temperature of the corresponding memory chip does not meet the temperature requirement, the sensor output signal being connected to an intermediate node; a current source connected to the intermediate node; and a control circuit configured to provide chip control signals to the plurality of memory chips.
    Type: Grant
    Filed: April 30, 2007
    Date of Patent: April 28, 2009
    Assignee: Qimonda North American Corp.
    Inventor: Wolfgang Hokenmaier
  • Patent number: 7518930
    Abstract: In a method for generating a selected word line voltage, a constant voltage that is substantially independent of a temperature change is generated. Additionally, a current that varies in proportion to a temperature is generated. To generate the selected word line voltage, the current is converted to a voltage that varies in proportion to the absolute temperature and the voltage is subtracted from the constant voltage.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: April 14, 2009
    Assignee: SanDisk Corporation
    Inventor: Toru Miwa
  • Publication number: 20090086554
    Abstract: A method for operating a semiconductor memory cell is disclosed. A first voltage is applied to the memory cell. The first voltage is dependent on temperature and semiconductor process variation in a manner that keeps the memory cell in a stable region of operation.
    Type: Application
    Filed: September 28, 2007
    Publication date: April 2, 2009
    Inventors: Christophe Chanussot, Vincent Gouin
  • Patent number: 7512025
    Abstract: A system and method for sensing a data state stored by a memory cell that includes coupling a first digit line and a second digit line to a precharge voltage and further coupling a memory cell to the first digit line. At least one digit line other than the first and second digit lines is driven to a reference voltage level and the at least one digit line is coupled to the second digit line to establish a reference voltage in the second digit line. A voltage differential is sensed between the first digit line and the second digit line, and a data state based on the voltage differential is latched in response.
    Type: Grant
    Filed: January 18, 2008
    Date of Patent: March 31, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Sei Seung Yoon, Charles L. Ingalls, David Pinney, Howard C. Kirsch
  • Patent number: 7508722
    Abstract: A memory device has data transceivers, write strobe transceivers, and read strobe transceivers. The data transceivers transfer input data to the memory device and transfer output data from the memory device. The write strobe transceivers transfer timing information of the input data. The read strobe transceivers transfer timing information of the output data. The memory device also has an auxiliary circuit for generating auxiliary information. The auxiliary information includes information different from the timing information of the input data and the output data. The auxiliary circuit uses the write and read transceivers to transfer the auxiliary information to and from the memory device.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: March 24, 2009
    Assignee: Micron Technology, Inc.
    Inventors: Joo S. Choi, Troy A. Manning
  • Publication number: 20090067266
    Abstract: Self-calibration for a memory controller is performed by writing a voltage to a selected cell. Adjacent cells around the selected cell are programmed. After each of the adjacent programming operations, the voltage on the selected cell is read to determine any change in voltage caused by systemic offsets such as, for example, floating gate-to-floating gate coupling. These changes are averaged and stored in a table as an offset for use in adjusting a programming voltage or a read voltage in a particular area of memory represented by the offset. Self calibration method for temperature is determined by writing cells at different temperatures and reading at different temperatures to generate temperature offset tables for the write path and read path. These offset tables are used to adjust for systematic temperature related offsets during programming and during read.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 12, 2009
    Inventors: Frankie F. Roohparvar, Vishal Sarin, Jung-Sheng Hoei
  • Patent number: 7502272
    Abstract: A semiconductor memory device having a control circuit, decoder circuit, a dummy column, and a normal memory cell array divided in clusters of N consecutive rows, where N can be one or more than one, and for each cluster of N rows a common circuitry is used in block with a dummy bit line connected to the dummy column and to a timing circuit. A normal bit line connected to the normal memory cells provides the read normal bit to input/output logic. Whenever a normal memory cell is accessed during the read operation, the circuitry of the corresponding dummy row enables the dummy bit line to discharge, and when the voltage across the dummy bit line reaches a predetermined value, the timing circuit produces a timing signal to activate the input/output circuitry to read the data stored in the accessed memory cell.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: March 10, 2009
    Assignee: STMicroelectronics Pvt. Ltd.
    Inventor: Nasim Ahmad
  • Patent number: 7502274
    Abstract: For sensing a target temperature, first and second temperature detectors generate first and second delay signals having negative and positive delay changes with temperature. A comparator senses the target temperature from the first and second delay signals such as by activating an output signal when the temperature is at least the target temperature.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: March 10, 2009
    Assignee: Samsung Electroncis Co., Ltd.
    Inventors: Hoon Lee, Hoe-Ju Chung
  • Patent number: 7499361
    Abstract: A dynamic random access memory (DRAM) device has an array of DRAM cells of rows by columns. Each DRAM cell of the array is coupled with a wordline of a corresponding row and a bitline of a corresponding column. An entry into and an exit from the self-refresh mode are detected by a mode detector and a self-refresh mode signal is provided. An oscillation circuit generates in response to the self-refresh mode signal generates a basic time period. A first frequency divider/time period multiplier changes the basic time period in accordance with a process variation factor relating to the DRAM device. A second frequency divider/time period multiplier further changes the changed time period in accordance with a temperature change factor relating to the DRAM device. In the self-refresh mode, data stored in the DRAM cells is refreshed. In accordance with the two factors, the DRAM devices perform and achieve reliable self-refresh for variable DRAM cell retention time.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: March 3, 2009
    Assignee: MOSAID Technologies Incorporated
    Inventor: Hong Beom Pyeon
  • Publication number: 20090052265
    Abstract: A semiconductor memory device includes a memory core circuit having memory cells for storing data, a circuit configured to refresh the memory core circuit at a refresh interval, a temperature detecting unit configured to detect temperature, and a control circuit configured to shorten the refresh interval immediately in response to detection of a predetermined temperature rise by the temperature detecting unit and to elongate the refresh interval after refreshing every one of the memory cells at least once in response to detection of a temperature drop by the temperature detecting unit.
    Type: Application
    Filed: November 3, 2008
    Publication date: February 26, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Akinobu SHIROTA, Kuninori Kawabata
  • Patent number: 7495985
    Abstract: Memory component temperature information is used to implement a method for ODT (on die termination) thermal load management. A respective temperature of a plurality of memory components are accessed, and based on this temperature, an ODT cycle is directed to a first of the memory components to avoid imposing a thermal load from the ODT cycle on a second of the memory components.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: February 24, 2009
    Assignee: Nvidia Corporation
    Inventors: David G. Reed, Brad W. Simeral, Roman Surgutchik, Joshua Titus
  • Patent number: 7489556
    Abstract: Method and apparatus for generating a word-line voltage are disclosed. A word-line voltage generator includes a first current source, an adjustable current source, and a voltage converter, all operably coupled to a current sum node. The first current source generates a first current wherein a voltage derived from the first current at least partially comprises a cell location-dependent temperature coefficient varying with a location of a memory cell in a string of interconnected bit cells. The adjustable current source generates a second current that is substantially independent of a temperature change. The voltage converter is configured for generating a word-line signal having a word-line voltage proportional to the first current.
    Type: Grant
    Filed: May 12, 2006
    Date of Patent: February 10, 2009
    Assignee: Micron Technology, Inc.
    Inventor: Toru Tanzawa
  • Patent number: 7489580
    Abstract: A refresh period generating circuit which generates a refresh period in refreshing a DRAM cell, comprising: an oscillation circuit which oscillates at a frequency with temperature dependence on ambient temperature; a dividing circuit which divides an oscillation output of the oscillation circuit; a temperature detector which detects the ambient temperature; and a selector which switches and selects among division outputs with respective frequencies from the dividing circuit based on an output of the temperature detector, and outputs a signal as a reference of the refresh period. The temperature dependence in the oscillation circuit includes a positive temperature coefficient in a predetermined temperature range, and does not include a positive temperature coefficient out of the predetermined temperature range. The selector switches the division outputs out of the predetermined temperature range.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: February 10, 2009
    Assignee: Elpida Memory, Inc.
    Inventors: Yutaka Ito, Nobuhiro Odaira
  • Patent number: 7489578
    Abstract: A voltage level of a boosted voltage is prevented from being targeted at voltage level that is too low, thereby improving a write recovery time (tWR) characteristic in a memory in a semiconductor memory device. The boosted voltage level detector includes: a voltage divider for dividing a boosted voltage and outputting a divided voltage; and a comparison unit for comparing a reference voltage corresponding to a voltage level of a target voltage with the divided voltage and outputting a level detecting signal, wherein the voltage divider includes: a first voltage drop element connected between a boosted voltage terminal and an output terminal of the voltage divider, having a negative temperature coefficient; and a second voltage drop element connected between the output terminal of the voltage divider and a ground voltage terminal, having a positive temperature coefficient.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: February 10, 2009
    Assignee: Hynix Semiconductor Inc.
    Inventor: Kee-Teok Park
  • Patent number: 7489579
    Abstract: A control device and method are used for adjusting the refresh rate of a memory module in a computer system. The device includes a thermo sensor and a control circuit. In the control method, the thermo sensor actively outputs a temperature change signal in response to the temperature change in the memory module when a capacitor of the memory module incurs an aggravated current leakage due to the temperature rise. Next, the control circuit adjusts the refresh rate in response to the temperature change signal and refreshes the memory module at the refresh rate.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: February 10, 2009
    Assignee: Via Technologies, Inc.
    Inventor: Kuan-Jui Ho
  • Patent number: 7477567
    Abstract: A memory storage device is provided that includes a storage cell having a changeable magnetic region. The changeable magnetic region includes a material having a magnetization state that is responsive to a change in temperature. The memory storage device also includes a heating element. The heating element is proximate to the storage cell for selectively changing the temperature of the changeable magnetic region of said storage cell. By heating the storage cell via the heating element, as opposed to heating the storage cell by directly applying current thereto, more flexibility is provided in the manufacture of the storage cells.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: January 13, 2009
    Assignee: International Business Machines Corporation
    Inventors: David W. Abraham, Philip L. Trouilloud
  • Patent number: 7474580
    Abstract: A semiconductor memory integrated circuit for controlling a refresh operation includes: a first period generating unit that generates a first periodic signal having an uniformed period; a second period generating unit that generates a second periodic signal according to a first control signal; a period generation control unit that generates a timing signal for every predetermined period; a frequency dividing unit that divides the frequency of the first periodic signal into at least one frequency-divided periodic signals; and a period selection control unit that controls the operation of the second period generating unit according to the at least one frequency-divided periodic signals and the second periodic signal, determines temperature, and outputs one of the frequency-divided periodic signals corresponding to the determined temperature as a refresh signal.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: January 6, 2009
    Assignee: Hynix Semiconductor Inc.
    Inventors: Jong-Yeol Yang, Tae-Woo Kwon