Reference Or Dummy Element Patents (Class 365/210.1)
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Publication number: 20100284232Abstract: The invention provides a tracking circuit of a memory circuit. The tracking circuit is coupled between a control circuit and a sense amplifier, delays a word-line pulse signal generated by the control circuit by a delay period to generate a sense amplifier enable signal enabling the sense amplifier to detect data bits output by a memory cell array. In one embodiment, the tracking circuit comprises a plurality of dummy cells and a dummy bit line. At least one of the plurality of dummy cells comprises a plurality of cascaded transistors cascaded between the dummy bit line and a ground voltage for lowering down a dummy bit line signal on the dummy bit line when the word-line pulse signal is enabled. The dummy bit line is coupled to the dummy cells and carries the dummy bit line signal.Type: ApplicationFiled: July 22, 2010Publication date: November 11, 2010Applicant: MEDIATEK INC.Inventor: Chia Wei Wang
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Patent number: 7830705Abstract: Provided are a phase change memory device and a reading method thereof. An example embodiment of a phase change memory device may include main cells programmed to have any one of a plurality of resistance states respectively corresponding to multi-bit data, reference cells programmed to have at least two respectively different resistance states among the resistance states each time the main cells are programmed, and a reference voltage generation circuit sensing the reference cells to generate reference voltages for identifying each of the resistance states.Type: GrantFiled: July 7, 2008Date of Patent: November 9, 2010Assignee: Samsung Electronics Co., Ltd.Inventor: Gi-Tae Jeong
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Publication number: 20100277972Abstract: First and second memory cell arrays are adjacent in a first direction. First and second areas are positioned adjacent to one and the other side of the first memory array in a second direction. Third and fourth areas are positioned adjacent to one and the other side of the second memory array in a second direction. A sense amplifier is arranged in the first area and a current sink is arranged in the fourth area. The sense amplifier compares a read current which flows into the current sink via a memory cell in the first memory cell array and the second area from the sense amplifier with a reference current which flows into the current sink via the third area and a reference memory cell in the second memory cell array from the sense amplifier.Type: ApplicationFiled: April 28, 2010Publication date: November 4, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Yoshihiro UEDA
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Publication number: 20100277999Abstract: A fuse circuit includes a fuse unit configured to drive an output terminal via a current path including a fuse in response to a fuse enable signal; and a comparison unit configured to be activated in response to an activation signal for comparing a reference voltage having a predetermined level with a voltage level of the output terminal to generate a fuse state signal.Type: ApplicationFiled: June 30, 2009Publication date: November 4, 2010Inventor: Chang-Ho Do
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Publication number: 20100277975Abstract: A semiconductor memory device includes a plurality of memory cells configured to correspond to each of a plurality of word lines for storing data; a plurality of reference memory cells configured to include first and second magnetic memory devices, whose lower electrodes are commonly connected to each other, to generate a reference current corresponding to each of the memory cells; and a sense amplification unit configured to sense and amplify the reference current and a data current corresponding to a memory cell connected to an activated word line among the word lines.Type: ApplicationFiled: June 22, 2009Publication date: November 4, 2010Inventors: Sung-Yeon Lee, Young-Hoon Oh
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Patent number: 7826272Abstract: The present invention solves a problem of the degradation of the long-term reliability of a conventional semiconductor memory device due to early deterioration of a FET included in a reference cell therein. DRAM 1 has word lines 101 to 10n, word lines 22 and 24, memory cells 301 to 30n and a reference cell 40. Gates of FETs 32 in the memory cells 301 to 30n are connected to the word lines 101 to 10n respectively. Gates of a FET 42 and a FET 44 in the reference cell 40 are connected to the word line 22 for readout and the word line 24 for writing respectively. Here, potentials applied to the word lines 22 and 24 are lower than those applied to the word lines 101 to 10n.Type: GrantFiled: August 9, 2007Date of Patent: November 2, 2010Assignee: NEC Electronics CorporationInventor: Takashi Sakoh
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Patent number: 7821854Abstract: Address comparison circuits each compare the defect addresses programmed in the redundancy fuse circuits with an access address and output a redundancy signal when a comparison result is a match. A switch circuit is controlled to switch according to a redundancy selection signal output from a selection fuse circuit, and validates in response to the redundancy signal either a corresponding regular redundancy line or the reservation redundancy line. By dividing the redundancy lines into the regular redundancy lines and the reservation redundancy line, each of the redundancy fuse circuits can be made to correspond to one of the plurality of redundancy lines with the simple switch circuit. Therefore, a difference in propagation delay time of a signal can be made small and a difference in access time can be made small between when relieving a defect and when there is no defect.Type: GrantFiled: September 26, 2008Date of Patent: October 26, 2010Assignee: Fujitsu Semiconductor LimitedInventor: Hiroyuki Kobayashi
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Publication number: 20100265783Abstract: A reference current integrator and a sensed current integrator are coupled to form a differential sense amplifier. The differential sense amplifier is coupled to receive a bitline current signal from a flash memory, and the reference current integrator is coupled to receive a current signal from a reference memory cell. Integration continues until a desired voltage or time is reached, resulting in a sufficiently reliable output. The differential current integrating sense amplifier is also used for instrumentation, communication, data storage, sensing, biomedical device, and analog to digital conversion.Type: ApplicationFiled: June 30, 2010Publication date: October 21, 2010Applicant: Infineon Technologies AGInventor: Thomas Kern
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Publication number: 20100259970Abstract: A resistance change memory device including a substrate, first and second wiring lines formed above the substrate to be insulated from each other, and memory cells disposed between the first and second wiring lines, wherein the memory cell includes: a variable resistance element for storing as information a resistance value; and a Schottky diode connected in series to the variable resistance element. The variable resistance element has: a recording layer formed of a composite compound containing at least one transition element and a cavity site for housing a cation ion; and electrodes formed on the opposite sides of the recording layer, one of which serves as a cation source in a write or erase mode for supplying a cation to the recording layer to be housed in the cavity site therein.Type: ApplicationFiled: June 22, 2010Publication date: October 14, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Haruki TODA, Koichi Kubo
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Patent number: 7813182Abstract: A semiconductor memory has a first-stage amplifier circuit, wherein data stored in a memory cells is read based on a potential between an amplifier input MOS transistor and an amplifier reference MOS transistor, the potential being outputted from the first-stage amplifier circuit.Type: GrantFiled: November 17, 2008Date of Patent: October 12, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Yoshihiko Kamata, Takayuki Harima, Yasuhiko Honda
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Publication number: 20100254177Abstract: A non-volatile storage apparatus includes a set of Y lines, a common X line, multiple data storage elements each of which is connected to the common X line, a dummy storage element connected to the common X line and a particular Y line, and control circuitry in communication with the common X line and the set of Y lines. The multiple data storage elements are capable of being in a first state or a second state. The dummy storage element is in a conductive state. The control circuitry provides control signals to the common X line and the set of Y lines to change a first data storage element of the multiple data storage elements from the first state to the second state by passing a current into the first data storage element from the particular Y line through the dummy storage element.Type: ApplicationFiled: April 3, 2009Publication date: October 7, 2010Inventor: Roy E. Scheuerlein
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Publication number: 20100254207Abstract: A non-volatile memory device has an array of non-volatile memory cells, a first plurality of non-volatile memory reference cells, with each reference cell capable of being programmed to a reference level different from the other reference cells; and a second plurality of comparators. Each of the comparators is connectable to one of the first plurality of non-volatile memory reference cells and to one of a third plurality of memory cells from among the array of non-volatile memory cells.Type: ApplicationFiled: March 16, 2010Publication date: October 7, 2010Applicant: SILICON STORAGE TECHNOLOGY, INC.Inventors: Xian Liu, Michael James Heinz, Eugene Jinglun Tam, Michael K. Doan, Alexander Kotov, Tho Ngoc Dang, Jack Edward Frayer, Jung Hee Yun, Thuan T. Vu
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Patent number: 7808830Abstract: A semiconductor device includes a first reference cell used for programming or reading non-volatile memory cells, and an adjustment circuit adjusting a first reference level of the first reference cell when the first reference level is changed.Type: GrantFiled: February 5, 2008Date of Patent: October 5, 2010Assignee: Spansion LLCInventor: Yoshinori Kasuta
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Publication number: 20100246302Abstract: In a semiconductor memory device storing a resistance difference as information, a long time is taken so as to charge and/or discharge a selected cell by an equalizer circuit, which results in a difficulty of a high speed operation. A selection circuit puts, in a selected state, at least three bit lines which includes a selected bit line connected to a selected memory cell together with unselected bit lines adjacent to the selected bit line on both sides of the selected bit line. The selected and the unselected bit lines are coupled to sense amplifiers through an equalizer circuit. The equalizer circuit puts both the selected and the unselected bit lines into charging states and thereafter puts only the selected bit line into a discharging state to perform a sensing operation. On the other hand, the unselected bit lines are continuously kept at the charging states during the sensing operation. This makes it possible to perform the sensing operation at a high speed with a rare malfunction.Type: ApplicationFiled: March 24, 2010Publication date: September 30, 2010Applicant: ELPIDA MEMORY, INC.Inventor: Akiyoshi SEKO
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Publication number: 20100246284Abstract: A semiconductor memory cell includes a floating body region configured to be charged to a level indicative of a state of the memory cell; a first region in electrical contact with said floating body region; a second region in electrical contact with said floating body region and spaced apart from said first region; a gate positioned between said first and second regions; and a back-bias region configured to inject charge into or extract charge out of said floating body region to maintain said state of the memory cell. Application of back bias to the back bias region offsets charge leakage out of the floating body and performs a holding operation on the cell. The cell may be a multi-level cell. Arrays of memory cells are disclosed for making a memory device.Type: ApplicationFiled: June 9, 2010Publication date: September 30, 2010Inventors: Yuniarto Widjaja, Zvi Or-Bach
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Patent number: 7804717Abstract: A dummy cell includes a plurality of first memory cells MC for storing “1” or “0”, arranged at points of intersection between a plurality of word lines WR0 to WR7 and a plurality of first data lines D0 to D7, a plurality of first dummy cells MCH for storing “1” or “0”, arranged at points of intersection between the word lines WR0 to WR7 and a first dummy data line, and a plurality of second dummy cells MCL for storing “0”, arranged at points of intersection between the word lines WR0 to WR7 and a second dummy data line DD1.Type: GrantFiled: May 29, 2009Date of Patent: September 28, 2010Assignee: Hitachi, Ltd.Inventors: Satoru Hanzawa, Takeshi Sakata
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Patent number: 7804716Abstract: Provided are a flash memory device having an improved bit-line layout and a layout method for the flash memory device. The flash memory device in which bit lines are disposed based on double patterning technology (DPT), may include at least one main bit line connected to a cell string including a memory cell storing data, at least one dummy bit line disposed parallel to the at least one main bit line, and a common source line transferring a common source voltage, and disposed on a different layer from a layer on which the at least one main bit line and the at least one dummy bit line are disposed, wherein the at least one dummy bit line may include a first dummy bit line transferring a first voltage and a second dummy bit line transferring a second voltage.Type: GrantFiled: August 1, 2008Date of Patent: September 28, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Pan-suk Kwak, Doo-youl Lee
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Patent number: 7800954Abstract: The method for reading data according to example embodiments includes comparing a threshold voltage of a memory cell with a first boundary voltage, comparing the threshold voltage with a second boundary voltage having a higher voltage level than that of the first boundary voltage, and determining data of the memory cell based on the threshold voltage, the first boundary voltage, and the second boundary voltage.Type: GrantFiled: January 17, 2008Date of Patent: September 21, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Seung-Hwan Song, Jun Jin Kong, Sung Chung Park, Dong Hyuk Chae, Seung Jae Lee, Dong Ku Kang
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Patent number: 7800937Abstract: A method for writing a memory cell of a magnetoresistive random access memory (MRAM) device includes, sequentially, providing a first magnetic field in a first direction, providing a second magnetic field in a second direction substantially perpendicular to the first direction, turning off the first magnetic field, providing a third magnetic field in a third direction opposite to the first direction, turning off the second magnetic field, and turning off the third magnetic field. A method for switching magnetic moments in an MRAM memory cell includes providing a magnetic field in a direction forming a blunt angle with a direction of a bias magnetic field. A method for reading an MRAM device includes partially switching magnetic moments in a reference memory cell to generate a reference current; measuring a read current through a memory cell to be read; and comparing the read current with the reference current.Type: GrantFiled: July 18, 2008Date of Patent: September 21, 2010Assignee: Industrial Technology Research InstituteInventors: Chien-Chung Hung, Ming-Jer Kao, Yuan-Jen Lee, Lien-Chang Wang
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Publication number: 20100232244Abstract: A semiconductor memory device comprises: a memory cell array including a plurality of word lines, a plurality of bit line pairs containing a first bit line and a second bit line, and a plurality of memory cells; a plurality of replica bit lines formed in the same manner as the first and second bit lines; a write buffer circuit operative to drive the first or second bit line to the ground voltage; a replica write buffer circuit operative to drive the replica bit lines to the ground voltage; and a boot strap circuit operative to drive the first or second bit line currently driven to the ground voltage further to a negative potential at a timing when the potential on the replica bit lines reaches a certain value.Type: ApplicationFiled: September 11, 2009Publication date: September 16, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Osamu Hirabayashi
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Publication number: 20100232210Abstract: A semiconductor memory device includes variable resistance elements arranged in a memory area and configured to store data according to a resistance variation, each of the variable resistance elements having a first terminal electrically connected to a first line and a second terminal electrically connected to a second line, and dummy elements arranged in the memory area, formed of the same material as the variable resistance element and electrically isolated.Type: ApplicationFiled: March 12, 2010Publication date: September 16, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Takeshi KAJIYAMA, Yoshiaki ASAO
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Patent number: 7796451Abstract: Embodiments of the invention relate generally to data storage and computer memory, and more particularly, to systems, integrated circuits and methods to compensate for defective memory in third dimension memory technology. In a specific embodiment, an integrated circuit is configured to compensate for defective memory cells. For example, the integrated circuit can include a memory having memory cells that are disposed in multiple layers of memory. It can also include a memory reclamation circuit configured to substitute a subset of the memory cells for one or more defective memory cells. At least one memory cell in the subset of the memory cells resides in a different plane in the memory than at least one of the one or more defective memory cells.Type: GrantFiled: December 10, 2007Date of Patent: September 14, 2010Inventor: Robert Norman
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Patent number: 7796455Abstract: Devices controlling a phase change storage element and methods for increasing reliability of a phase change storage element. The invention introduces a first operation mode and a second operation mode. A reference phase change storage element is forced a write current for an ideal conduction period in the first operation mode. In the second operation mode, the invention generates a proper conduction period based on the resistance of the reference phase change storage element, and forces the write current into the controlled phase change storage element for the proper conduction period.Type: GrantFiled: June 19, 2008Date of Patent: September 14, 2010Assignee: Industrial Technology Research InstituteInventors: Pei-Chia Chiang, Shyh-Shyuan Sheu, Lieh-Chiu Lin, Wen-Pin Lin
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Patent number: 7796452Abstract: A semiconductor memory for maintaining a word line driving voltage includes a cell array and a sense amplifier adjacent to the cell array. A dummy cell is formed at a peripheral portion of the cell array in such a manner that a dummy bit line and a word line intersect. A control circuit switches the connection state between a first section of the dummy bit line passing through the cell array and a second section of the dummy bit line passing through the sense amplifier. The connection state switches according to the operation mode of the cell array. The dummy bit line is floated when the operation mode is an active mode and a precharge voltage is provided to the dummy bit line when the operation mode is a precharge mode.Type: GrantFiled: June 12, 2008Date of Patent: September 14, 2010Assignee: Hynix Semiconductor Inc.Inventor: Hyung Sik Won
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Patent number: 7791971Abstract: A semiconductor memory device includes first and second cell arrays which have memory cells arrayed in row and column directions, first and second bit lines which are connected to the memory cells arrayed in the column direction, and first and second sense amplifiers which are connected to the first, second bit lines, respectively. The device also includes first and second dummy cell arrays which have dummy cells arrayed in the row and column directions, a dummy word line which is connected to the dummy cells arrayed in the row direction, first and second dummy bit lines which are connected to the dummy cells arrayed in the column direction and receive an output from the dummy word line, and first and second sense amplifier activation circuits which activate the first, second sense amplifiers in accordance with first and second control signals output from the first and second dummy bit lines, respectively.Type: GrantFiled: April 27, 2009Date of Patent: September 7, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Akihito Tohata, Tomoaki Yabe
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Patent number: 7791946Abstract: The present invention is directed to a semiconductor device having a non-volatile memory cell 18, and a readout circuit 102 which reads out data of the memory cell 18 DATA using a first data DATA1 obtained by sensing a first reference level REF1 for reading out the data of the memory cell 18 and a level of the memory cell 18 CORE and using a second data DATA2 obtained by sensing a second reference level REF2 for reading out the data of the memory cell 18 and the level of the memory cell 18 CORE, and to a controlling method for the same.Type: GrantFiled: July 1, 2008Date of Patent: September 7, 2010Assignee: Spansion LLCInventors: Keiichirou Kikuchi, Hiroaki Wada, Norihiro Yamaki
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Patent number: 7791930Abstract: A MRAM includes a first magnetoresistive effect (MR) element that takes a low and high resistance states. A second MR element is fixed to a low or high resistance state. First and second MOSFETs are connected to the first and second MR elements, respectively. A sense amplifier amplifies a difference between values of current flowing through the first and second MOSFETs. A current circuit outputs reference current whose value lies between current flowing through the first MR element of the low and high resistance states. A third MOSFET has one end that receives the reference current and is connected to its own gate terminal. The gate terminal of the second MOSFET receives the same potential as the gate terminal of the third MOSFET. A first resistance element is connected to the others end of the third MOSFET and has the same resistance as the second magnetoresistive effect element.Type: GrantFiled: June 30, 2008Date of Patent: September 7, 2010Assignee: Kabushiki Kaisha ToshibaInventor: Yoshihiro Ueda
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Patent number: 7787278Abstract: Provided is a resistance variable memory device and a method for operating same. The resistance variable memory device has a phase change material between a top electrode and a bottom electrode. In the method for operating a resistance variable memory, the write current is applied in a direction from the top electrode to the bottom electrode, and the read current is applied in a direction from the bottom electrode to the top electrode. The phase change material is programmed by applying the write current, and a resistance drift of the phase change material is restrained by applying the read current.Type: GrantFiled: August 22, 2008Date of Patent: August 31, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Jun-Soo Bae, Hideki Horii, Mi-Lim Park
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Patent number: 7788528Abstract: A repair module for repairing one of n bit lines through m bit bus in a memory, a repair device using the same, and a method thereof are provided herein, wherein m?n. In the repair method, a switching control signal and a selecting control signal are generated according to an index value of the one of n bit lines. A dummy line is switched to the one of n bit lines by shifting from 1st bit line to the one of n bit line one by one according to the switching control signal for replacing the one of n bit lines. Then, the Lth bit line or the dummy line is selected for signal transmission according to the selecting control signal, wherein 1?L?m. Therefore, the data can be transmitted through the undamaged bit line by replacing the defective bit line with the dummy line.Type: GrantFiled: May 23, 2008Date of Patent: August 31, 2010Assignee: Himax Technologies LimitedInventor: Yaw-Guang Chang
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Publication number: 20100214861Abstract: A semiconductor memory cell array includes a plurality of bit-lines, a plurality of word-lines, a plurality of memory cells, a plurality of dummy memory cells, a plurality of dummy bit-lines, and a plurality of dummy word-lines. The dummy bit-lines are in outer regions of the bit-lines. The dummy word-lines are in outer regions of the word-lines. The dummy bit-lines are maintained in a floating state.Type: ApplicationFiled: February 22, 2010Publication date: August 26, 2010Inventors: Sang-Woong Shin, Seong-Jin Jang
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Patent number: 7782695Abstract: A sensing circuit with current offset functionality. In one embodiment, the sensing circuit includes a memory circuit having a first offset circuit operative to offset a first current. The sensing circuit also includes a reference circuit coupled to the memory circuit, where the reference circuit includes a second offset circuit operative to offset a second current. The sensing circuit also includes a compare circuit coupled to the memory circuit and the reference circuit, where the compare circuit determines the state of a memory cell based on first current and the second current. According to the system disclosed herein, the first and second offset circuits optimize the performance of the sensing circuit and prevent errors when determining the state of the memory cell.Type: GrantFiled: January 12, 2007Date of Patent: August 24, 2010Assignee: Atmel CorporationInventors: Lorenzo Bedarida, Gabriele Pelli, Simone Bartoli, Mauro Chinosi
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Publication number: 20100208511Abstract: A memory device includes a plurality of memory bit lines connected to a plurality of memory cells, a plurality of reference bit lines connected to a plurality of reference cells and a reference bit line selection circuit. The memory bit lines has a first pattern and a second pattern, and the first pattern has a first critical dimension (CD) distribution, and the second pattern has a second CD distribution. The reference bit lines have the first pattern and the second pattern. The reference bit line selection circuit provides a reference signal by selecting a reference bit line having a same pattern as a selected memory bit line connected to a memory cell to be read.Type: ApplicationFiled: February 18, 2010Publication date: August 19, 2010Inventors: Hyoung Seub Rhie, Suk-Joo Lee
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Patent number: 7778098Abstract: A memory cell array includes reference cells each associated with a plurality of data cells of the array.Type: GrantFiled: December 31, 2007Date of Patent: August 17, 2010Assignee: Cypress Semiconductor CorporationInventors: Andreas Scade, Stefan Guenther
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Patent number: 7778065Abstract: An apparatus for sensing the data state of a multiple level, programmable resistive memory device includes an active clamping device connected to a data leg that is selectively coupled a programmable resistive memory element, the clamping device configured to clamp a fixed voltage, at a first node of the data leg, across the memory element, thereby establishing a fixed current sinking capability thereof; and a plurality of differential amplifiers, each of the differential amplifiers configured to compare a first voltage input, taken at a second node of the data leg, with a second voltage input; wherein the second voltage input for each differential amplifier comprises different reference voltages with respect to one another so as to enable each differential amplifier to detect a different resistance threshold, thereby determining a specific resistance state of the programmable resistive memory element.Type: GrantFiled: February 29, 2008Date of Patent: August 17, 2010Assignee: International Business Machines CorporationInventors: Mark C. H. Lamorey, Thomas M. Maffitt
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Publication number: 20100202188Abstract: A low read current architecture for memory. Bit lines of a cross point memory array are allowed to be charged by a selected word line until a minimum voltage differential between a memory state and a reference level is assured.Type: ApplicationFiled: April 19, 2010Publication date: August 12, 2010Applicant: UNITY SEMICONDUCTOR CORPORATIONInventors: Darrell Rinerson, Christophe Chevallier, Chang Hua Siau
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Publication number: 20100202231Abstract: A non volatile memory device comprises memory cells such as MRAM cells, reading circuits and a reference cell for generating a reference for use by the reading circuits, and can determine if the reference is degraded by thermal instability. This can help reduce a data error rate. Detecting such degradation can prove to be more effective than trying to design in enough margins for the lifetime of the device. The reference cell can be less susceptible to degradation than other cells by using different shape of cells and different write currents. Where each reference cell is used by many memory cells, the reference cell tends to be used more often than any particular memory cell and so can be more susceptible to degradation. Another way of ensuring against longer term degradation of the reference is periodically rewriting the reference cell.Type: ApplicationFiled: April 23, 2010Publication date: August 12, 2010Applicant: NXP B.V.Inventor: Hans Marc Bert Boeve
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Publication number: 20100202213Abstract: A sense amplifying method, applied in a memory having a memory cell and a reference cell, includes: charging the memory cell and the reference cell to have a cell current and a reference current, respectively; duplicating the cell current and the reference current to respectively generate a mirrored cell current via a first current path and a mirrored reference current via a second current path and equalizing a first voltage drop generated as the mirrored cell current flows by the first current path and a second voltage drop generated as the mirrored reference current flows by the second current path; and removing the equalization of the first voltage drop and the second voltage drop and adjusting first voltage drop and the second voltage drop according to a first current flowing by the first current path and a second current flowing by the second current path.Type: ApplicationFiled: April 26, 2010Publication date: August 12, 2010Applicant: MACRONIX INTERNATIONAL CO. LTD.Inventors: Yung-Feng Lin, Chun-Yi Lee
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Patent number: 7773444Abstract: A semiconductor memory device having a first memory cell array block including a memory cell having a floating body, the memory cell coupled to a word line, a first bit line, and a first source line, a second memory cell array block including a reference memory cell having a floating body, the reference memory cell coupled to a reference word line, a second bit line, and a second source line, a first isolation gate portion configured to selectively transmit a signal between the first bit line and at least one of a sense bit line and an inverted sense bit line, a second isolation gate portion configured to selectively transmit a signal between the second bit line and at least one of the sense bit lines, and a sense amplifier configured to amplify voltages of the sense bit line and the inverted sense bit line to first and second sense amplifying voltage levels.Type: GrantFiled: November 15, 2006Date of Patent: August 10, 2010Assignee: Samsung Electronics Co., Ltd.Inventor: Yeong-Taek Lee
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Patent number: 7773425Abstract: A nonvolatile semiconductor memory that improved a read rate. In a memory cell array in which each memory cell includes two storage areas, thresholds of outer storage areas of two memory cells which are symmetrical with respect to two adjacent bit lines are set so as to create a pair relation between them. A word line selection circuit applies read voltage to a word line to which the two memory cells to be read are connected. A bit line selection circuit applies ground voltage to two bit lines just outside the two memory cells and applies predetermined read voltage to two bit lines inside the two memory cells. A read conversion circuit compares drain currents which run through the two memory cells activated by the word line selection circuit and the bit line selection circuit, and converts the drain currents into data.Type: GrantFiled: September 28, 2007Date of Patent: August 10, 2010Assignee: Fujitsu Semiconductor LimitedInventors: Motoi Takahashi, Ikuto Fukuoka
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Patent number: 7773443Abstract: A memory array includes a sensing circuit for sensing bit line current while keeping the voltage of the selected bit line substantially unchanged. The word lines and bit lines are biased so that essentially no bias voltage is impressed across half-selected memory cells, which substantially eliminates leakage current through half-selected memory cells. The bit line current which is sensed arises largely from only the current through the selected memory cell. A noise detection line in the memory array reduces the effect of coupling from unselected word lines to the selected bit line. In a preferred embodiment, a three-dimensional memory array having a plurality of rail-stacks forming bit lines on more than one layer, includes at least one noise detection line associated with each layer of bit lines. A sensing circuit is connected to a selected bit line and to its associated noise detection line.Type: GrantFiled: March 16, 2009Date of Patent: August 10, 2010Assignee: SanDisk 3D LLCInventor: Roy E. Scheuerlein
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Publication number: 20100195382Abstract: A tunnel magnetic resistive element forming a magnetic memory cell includes a fixed magnetic layer having a fixed magnetic field of a fixed direction, a free magnetic layer magnetized by an applied magnetic field, and a tunnel barrier that is an insulator film provided between the fixed and free magnetic layers in a tunnel junction region. In the free magnetic layer, a region corresponding to an easy axis region having characteristics desirable as a memory cell is used as the tunnel junction region. A hard axis region having characteristics undesirable as a memory cell is not used as a portion of the tunnel magnetic resistive element.Type: ApplicationFiled: April 6, 2010Publication date: August 5, 2010Applicant: RENESAS TECHNOLOGY CORPInventor: Hideto Hidaka
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Publication number: 20100195422Abstract: A semiconductor integrated circuit includes: a current difference sense type of a sense amplifier including: an input line connected to memory cells as a target to be read, a reference line connected to reference cells, and a first pre-charge circuit configured to pre-charge the input line and the reference line; a second pre-charge circuit configured to perform pre-charging of the input line and pre-charging of the reference line; and a control circuit configured to control the second pre-charge circuit so that the second pre-charge circuit may perform both the pre-charging of the input line and the pre-charging of the reference line independently of each other, and start both the pre-charging of the input line and the pre-charging of the reference line earlier than pre-charging by the first pre-charge circuit.Type: ApplicationFiled: December 29, 2009Publication date: August 5, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Seiro Imai
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Patent number: 7768813Abstract: In one embodiment, a DRAM is provided that includes: a word line intersecting with a pair of bit lines, the DRAM including a memory cell at each intersection, each memory cell including an access transistor adapted to couple a storage cell to the corresponding bit line if its gate voltage is raised; and a word line compensation circuit adapted to compensate for a capacitively-coupled voltage increase on the corresponding bit line if the access transistor's gate voltage is raised.Type: GrantFiled: August 27, 2007Date of Patent: August 3, 2010Assignee: Novelics, LLC.Inventors: Esin Terzioglu, Melinda L. Miller
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Publication number: 20100182833Abstract: A memory and a boundary searching method thereof are provided therein. When searching a boundary of a threshold voltage distribution of the memory, data errors resulted from tail bits of the memory would be corrected. Therefore, a sensing window could be broader, and the boundary of the threshold voltage distribution could be determined precisely.Type: ApplicationFiled: January 19, 2009Publication date: July 22, 2010Applicant: MACRONIX International Co., Ltd.Inventors: Chung-Kuang Chen, Han-Sung Chen, Chun-Hsiung Hung
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Patent number: 7760543Abstract: A resistance change memory includes a memory cell which is connected to a first node, and programmed from a first resistance state to a second resistance state, a first replica cell which is connected to a second node, generates a write voltage for programming from the first resistance state to the second resistance state, and is fixed in the first resistance state, and a first constant-current source connected to the second node, wherein when writing the second resistance state in the memory cell, a voltage of the first node is held equal to that of the second node.Type: GrantFiled: October 2, 2008Date of Patent: July 20, 2010Assignee: Kabushiki Kaisha ToshibaInventor: Yoshihiro Ueda
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Publication number: 20100177580Abstract: Even when memory capacity of a memory that uses a replica bit-line is made higher, fluctuations of a generating timing of a sense-amplifier enable signal are reduced. A semiconductor integrated circuit device comprises a plurality of word lines, a plurality of bit-lines, a plurality of ordinary memory cells, an access control circuit, a plurality of sense-amplifiers, first and second replica bit-lines, first and second replica memory cells, and first and second logic circuits. The first and second replica memory cells are connected to the first and second replica bit-lines, respectively; inputs of the first and second logic circuits are connected to the first and second replica bit-lines, respectively; a sense-amplifier enable signal is generated from an output of the second logic circuit; and this signal is supplied to a plurality of sense-amplifiers.Type: ApplicationFiled: January 14, 2010Publication date: July 15, 2010Inventors: Shigenobu Komatsu, Masanao Yamaoka, Noriaki Maeda, Masao Morimoto, Yasuhisa Shimazaki
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Patent number: 7755964Abstract: A memory device with configurable delay tracking is described. The memory device includes M normal word line drivers, a dummy word line driver a memory array, N sense amplifiers, and a timing control circuit. The memory array includes M rows and N columns of memory cells and a column of dummy cells. The word line drivers drive word lines for the rows of memory cells. The dummy word line driver drives a dummy word line for at least one dummy cell in the column of dummy cells. The timing control circuit generates enable signals having configurable delay, which may be obtained with an acceleration circuit that provides variable drive for a dummy bit line coupled to the column of memory cells. The sense amplifiers detect bit lines for the columns of memory cells based on the enable signals.Type: GrantFiled: October 25, 2006Date of Patent: July 13, 2010Inventors: Seong-Ook Jung, Sei Seung Yoon, Yi Han
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Patent number: 7755965Abstract: A memory device that includes at least one memory cell, the memory cell includes: a magnetic tunnel junction (MTJ); and a transistor, wherein the transistor is operatively coupled to the MTJ; a bit line; a source line; and a word line, wherein the memory cell is operatively coupled between the bit line and the source line, and the word line is operatively coupled to the transistor; a temperature sensor; and control circuitry, wherein the temperature sensor is operatively coupled to the control circuitry and the control circuitry and temperature sensor are configured to control a current across the memory cell.Type: GrantFiled: October 13, 2008Date of Patent: July 13, 2010Assignee: Seagate Technology LLCInventors: Yiran Chen, Hai Li, Hongyue Liu, Henry F. Huang, Yong Lu
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Patent number: 7751227Abstract: Disclosed are a phase change memory with improved retention characteristic of a phase change device, and a method for refreshing the phase change memory. The fact that a memory is a DRAM interface compatible memory is exploited. There are provided dummy cells stressed in accordance with the number of times of read and write operations. Changes in the resistance value of the dummy cells are detected by comparator circuits. If the resistance value have been changed beyond a predetermined reference value (that is, changed to a low resistance), a refresh request circuit requests an internal circuit, not shown, to effect refreshing. The memory cells and the dummy cells are transitorily refreshed and correction is made for variations in the programmed resistance value of the phase change devices to assure the margin as well as to improve retention characteristic.Type: GrantFiled: July 10, 2009Date of Patent: July 6, 2010Assignee: Elpida Memory, Inc.Inventor: Yukio Fuji
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Publication number: 20100165719Abstract: A phase change memory device with memory cells (2) formed by a phase change memory element (3) and a selection switch (4). A reference cell (2a) formed by an own phase change memory element (3) and an own selection switch (4) is associated to a group (7) of memory cells to be read. An electrical quantity of the group of memory cells is compared with an analogous electrical quantity of the reference cell, thereby compensating any drift in the properties of the memory cells.Type: ApplicationFiled: July 26, 2007Publication date: July 1, 2010Inventor: Fabio PELLIZZER