Magnetic Patents (Class 365/209)
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Patent number: 8208291Abstract: A system and method to control a direction of a current applied to a magnetic tunnel junction is disclosed. In a particular embodiment, an apparatus comprises a magnetic tunnel junction (MTJ) storage element and a sense amplifier. The sense amplifier is coupled to a first path and to a second path. The first path includes a first current direction selecting transistor and the second path includes a second current direction selecting transistor. The first path is coupled to a bit line of the MTJ storage element and the second path is coupled to a source line of the MTJ storage element.Type: GrantFiled: January 14, 2010Date of Patent: June 26, 2012Assignee: QUALCOMM IncorporatedInventors: Jung Pill Kim, Hari M. Rao, Kangho Lee
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Patent number: 8203871Abstract: Spin torque magnetic logic devices that function as memory devices and that can be reconfigured or reprogrammed as desired. In some embodiments, the logic device is a single magnetic element, having a pinned layer, a free layer, and a barrier layer therebetween, or in other embodiments, the logic device has two magnetic elements in series. Two input currents can be applied through the element to configure or program the element. In use, logic input data, such as current, is passed through the programmed element, defining the resistance across the element and the resulting logic output. The magnetic logic device can be used for an all-function-in-one magnetic chip.Type: GrantFiled: November 30, 2010Date of Patent: June 19, 2012Assignee: Seagate Technology LLCInventors: Xiaohua Lou, Dimitar V. Dimitrov, Song S. Xue
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Publication number: 20120147664Abstract: A non-volatile memory and method for controlling the same prevents a faulty operation from being generated in a read operation, resulting in increase in operation reliability. The non-volatile memory device includes a cell array configured to include a plurality of unit cells in which a read or write operation of data is achieved in a unit cell in response to a variation of resistance, a reference cell array configured to include a plurality of reference cells, each of which has the same structure as that of the unit cell, a global reference current generation circuit configured to generate a global reference current corresponding to a position of the reference cell so as to verify data stored in the reference cell array, and a sense-amplifier configured to compare a current flowing in the reference cell array with the global reference current during a write verification operation of the reference cell array, and thus sense data.Type: ApplicationFiled: December 28, 2010Publication date: June 14, 2012Applicant: Hynix Semiconductor Inc.Inventor: Kwang Myoung RHO
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Patent number: 8194444Abstract: Self-reference reading a magnetic tunnel junction data cell methods are disclosed. An illustrative method includes applying a read voltage across a magnetic tunnel junction data cell and forming a read current. The magnetic tunnel junction data cell has a first resistance state. The read voltage is sufficient to switch the magnetic tunnel junction data cell resistance. The method includes detecting the read current and determining if the read current remains constant during the applying step. If the read current remains constant during the applying step, then the first resistance state of the magnetic tunnel junction data cell is the resistance state that the read voltage was sufficient to switch the magnetic tunnel junction data cell to.Type: GrantFiled: December 15, 2010Date of Patent: June 5, 2012Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Yiran Chen, Xiaobin Wang, Zheng Gao, Dimitar V. Dimitrov, Wenzhong Zhu, Yong Lu
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Patent number: 8179716Abstract: Spin torque magnetic logic device having at least one input element and an output element. Current is applied through the input element(s), and the resulting resistance or voltage across the output element is measured. The input element(s) include a free layer and the output element includes a free layer that is electrically connected to the free layer of the input element. The free layers of the input element and the output element may be electrically connected via magnetostatic coupling, or may be physically coupled. In some embodiments, the output element may have more than one free layer.Type: GrantFiled: November 24, 2010Date of Patent: May 15, 2012Assignee: Seagate Technology LLCInventors: Haiwen Xi, Yang Li, Song S. Xue
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Patent number: 8159871Abstract: A magnetoresistive memory cell includes an MTJ device and a select transistor. The select transistor includes a first conduction-type semiconductor layer, a gate electrode formed by disposing a gate insulating layer on top of the semiconductor layer, and first and second diffusion regions formed in the semiconductor layer to be spaced apart from each other and to have a second conduction type. A part of the semiconductor layer between the first and second diffusion regions is formed as an electrically floating body region. By using a high-performance select transistor with a floating body effect, high integration of a magnetoresistive memory device may be achieved.Type: GrantFiled: July 22, 2009Date of Patent: April 17, 2012Assignee: Hynix Semiconductor Inc.Inventor: Sung Woong Chung
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Patent number: 8154917Abstract: A magnetic storage device includes a plurality of MRAM memory cells connected to a data transfer line, a clamp transistor connected between the data transfer line and a reading signal line and configured to fixedly hold the potential of the data transfer line, and a reading circuit which is connected to the reading signal line and which reads the storage information of the memory cell. The reading circuit includes a hold switch connected between the reading signal line and a reading node N and configured to hold the potential of the node N, a capacitor connected between the node N and a ground end, a precharging switch connected between the node N and a power source and configured to charge the capacitor, and an inverter to which the potential of the node N is input to generate a digital signal.Type: GrantFiled: March 3, 2011Date of Patent: April 10, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Masanori Furuta, Daisuke Kurose, Tsutomu Sugawara
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Patent number: 8144504Abstract: Provided is a method of operating a magnetic random access memory device comprising a switch structure and a magnetoresistance structure. According to the method, current variation depending on the direction of the current can be reduced by controlling a gate voltage of the switch structure when supplying current to write data to the magnetoresistance structure.Type: GrantFiled: July 10, 2009Date of Patent: March 27, 2012Assignee: Samsung Electronics Co., Ltd.Inventors: Kwang-seok Kim, Sun-ae Seo, Kee-won Kim, In-jun Hwang, Hyung-soon Shin, Seung-yeon Lee, Seung-jun Lee
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Patent number: 8111572Abstract: Embodiments of the invention relate generally to data storage and computer memory, and more particularly, to systems, integrated circuits and methods for controlling memory disturbs to and among multiple layers of memory that include, for example, third dimensional memory technology. Each layer of memory can include a plurality of non-volatile memory cells that store data as a plurality of conductivity profiles that can be non-destructively read by applying a read voltage across a selected non-volatile memory cell. Data can be written to a selected non-volatile memory cell by applying a write voltage having a predetermined magnitude and polarity across the selected non-volatile memory cell. Stored data is retained in the plurality of non-volatile memory cells in the absence of power.Type: GrantFiled: December 12, 2007Date of Patent: February 7, 2012Inventor: Robert Norman
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Patent number: 8102703Abstract: A magnetic tunnel junction, including a reference layer having a fixed magnetization direction, a first storage layer having a magnetization direction that is adjustable relative to the magnetization direction of the reference layer by passing a write current through said magnetic tunnel junction, and an insulating layer disposed between said reference layer and first storage layer; characterized in that the magnetic tunnel junction further comprises a polarizing device to polarize the spins of the write current oriented perpendicular with the magnetization direction of the reference layer; and wherein said first storage layer has a damping constant above 0.02. A magnetic memory device formed by assembling an array of the magnetic tunnel junction can be fabricated resulting in lower power consumption.Type: GrantFiled: July 14, 2009Date of Patent: January 24, 2012Assignee: Crocus TechnologyInventors: Jean-Pierre Nozières, Bernard Dieny
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Patent number: 8077508Abstract: A circuit includes, in part, a multitude of magnetic random access memory cells, one or more column decoders, one or more row decoders, and a write driver circuit. The write driver circuit is responsive to data signal as well as to read/write signals. During writing of a first data to a selected magnetic random access memory cell, the write driver circuit causes the first signal line to be at a second voltage and the second signal line to be at the first voltage. The second voltage is greater than the first voltage. During writing of a second data to the selected magnetic random access memory cell, the write driver circuit cause the first signal line to be at a third voltage and the second signal line to be at the second voltage. The third voltage is smaller than the first voltage.Type: GrantFiled: August 19, 2009Date of Patent: December 13, 2011Assignee: Grandis, Inc.Inventor: Adrian E. Ong
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Patent number: 8059480Abstract: 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: GrantFiled: June 22, 2009Date of Patent: November 15, 2011Assignee: Hynix Semiconductor Inc.Inventors: Sung-Yeon Lee, Young-Hoon Oh
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Patent number: 8054706Abstract: A method and apparatus for protecting an electrical device using a non-volatile memory cell, such as an STRAM or RRAM memory cell. In some embodiments, a memory element is connected in parallel with a sensor element, where the memory element is configured to be repetitively reprogrammable between a high resistance state and a low resistance state. The memory element is programmed to the low resistance state when the sensor element is in a non-operational state and reprogrammed to the high resistance state when the sensor element is in an operational state.Type: GrantFiled: March 19, 2009Date of Patent: November 8, 2011Assignee: Seagate Technology LLCInventors: Phillip Mark Goldman, Muralikrishnan Balakrishnan
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Publication number: 20110170338Abstract: A system and method to control a direction of a current applied to a magnetic tunnel junction is disclosed. In a particular embodiment, an apparatus comprises a magnetic tunnel junction (MTJ) storage element and a sense amplifier. The sense amplifier is coupled to a first path and to a second path. The first path includes a first current direction selecting transistor and the second path includes a second current direction selecting transistor. The first path is coupled to a bit line of the MTJ storage element and the second path is coupled to a source line of the MTJ storage element.Type: ApplicationFiled: January 14, 2010Publication date: July 14, 2011Applicant: QUALCOMM INCORPORATEDInventors: Jung Pill Kim, Hari M. Rao, Kangho Lee
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Patent number: 7978542Abstract: An end of a selected bit line in a selected column is electrically coupled to an end of a corresponding current return line by one of first and second write column select gates, which are selectively turned on in response to results of column selection. A data write circuit sets the other end of the selected bit line and the other end of the current return line to one and the other of a power supply voltage and a ground voltage in accordance with a level of write data via one of first and second data buses and an inverted data bus, respectively.Type: GrantFiled: December 30, 2010Date of Patent: July 12, 2011Assignee: Renesas Electronics CorporationInventor: Hideto Hidaka
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Patent number: 7969805Abstract: A structure comprising (i) a first information device, (ii) a second information device, (iii) a first coupling element and (iv) a second coupling element is provided. The first information device has at least a first lobe and a second lobe that are in electrical communication with each other. The second information device and has at least a first lobe and a second lobe that are in electrical communication with each other. The first coupling element inductively couples the first lobe of the first information device to the first lobe of the second information device. The second coupling element inductively couples the first lobe of the first information device to the second lobe of the second information device.Type: GrantFiled: October 7, 2009Date of Patent: June 28, 2011Assignee: D-Wave Systems, Inc.Inventors: Murray C. Thom, Andrew J. Berkley, Alexander Maassen van den Brink
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Patent number: 7936627Abstract: A magnetoresistance effect element according to the present invention comprises a magnetization free layer 1 and a magnetization fixed layer 3 connected to the magnetization free layer 1 through a nonmagnetic layer 2. The magnetization free layer 1 includes a magnetization switching region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization switching region 13 having reversible magnetization overlaps with the magnetization fixed layer 3. The first magnetization fixed region 11 having first fixed magnetization is connected to one end 13a of the magnetization switching region 13. The second magnetization fixed region 12 having second fixed magnetization is connected to the other end 13b of the magnetization switching region 13. The first magnetization fixed region 11 and the magnetization switching region 13 form a three-way intersection, and the second magnetization fixed region 12 and the magnetization switching region 13 form another three-way intersection.Type: GrantFiled: October 22, 2007Date of Patent: May 3, 2011Assignee: NEC CorporationInventor: Shunsuke Fukami
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Patent number: 7931976Abstract: A magnetic recording element includes a multilayer having a surface and a pair of electrodes. The multilayer has a first magnetic fixed layer whose magnetization is substantially fixed in a first direction substantially perpendicular to the surface. The multilayer also has a second magnetic fixed layer whose magnetization is substantially fixed in a second direction opposite to the first direction substantially perpendicular to the surface. A third magnetic layer is provided between the first and second magnetic layers. The direction of magnetization of the third ferromagnetic layer is variable. A first intermediate layer is provided between the first and the third magnetic layers. A second intermediate layer is provided between the second and the third magnetic layers. The pair of electrodes is capable of supplying an electric current flowing in a direction substantially perpendicular to the surface to the multilayer.Type: GrantFiled: October 3, 2008Date of Patent: April 26, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Yuichi Ohsawa, Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida
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Patent number: 7929334Abstract: A method of measuring resistance of a magnetic tunnel junction (MTJ) of an MRAM memory cell includes applying a voltage of a selected level to a memory cell comprising an MTJ in series with a memory cell transistor in a conducting state. A current through the memory cell is determined. A variable voltage is applied to a replica cell not having an MTJ and comprising a replica cell transistor in a conducting state. A value of the variable voltage is determined, wherein a resulting current through the replica cell is substantially the same as the current through the memory cell. The MTJ resistance is computed by taking the difference of the memory cell voltage and the determined variable replica cell voltage and dividing the result by the determined memory cell current.Type: GrantFiled: January 29, 2009Date of Patent: April 19, 2011Assignee: QUALCOMM IncorporatedInventors: Hari Rao, Sei Seung Yoon, Xiaochun Zhu, Mohamed Abu-Rahma
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Patent number: 7920416Abstract: Magnetic random access memory (MRAM) devices and techniques for use thereof are provided. In one aspect, a magnetic memory cell is provided. The magnetic memory cell comprises at least one fixed magnetic layer; at least one first free magnetic layer separated from the fixed magnetic layer by at least one barrier layer; at least one second free magnetic layer separated from the first free magnetic layer by at least one spacer layer; and at least one capping layer over a side of the second free magnetic layer opposite the spacer layer. One or more of the first free magnetic layer and the second free magnetic layer comprise at least one rare earth element, such that the at least one rare earth element makes up between about one percent and about 10 percent of one or more of the first free magnetic layer and the second free magnetic layer.Type: GrantFiled: March 12, 2008Date of Patent: April 5, 2011Assignee: International Business Machines CorporationInventors: William J. Gallagher, Daniel C. Worledge
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Patent number: 7881138Abstract: A memory has a pre-amplifier for generating an output signal and a reference signal. The memory includes a comparator for comparing the output signal to the reference signal. The comparator includes a bias stage for generating a bias signal, wherein the bias signal is an average of the output signal and the reference signal. The comparator further includes a first output stage for generating a first comparator output signal by comparing the output signal and the bias signal. The comparator further includes a second output stage for generating a second comparator output signal by comparing the reference signal and the bias signal.Type: GrantFiled: July 10, 2006Date of Patent: February 1, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Brad Garni, Thomas Andre, Jean Lasseuguette
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Patent number: 7877244Abstract: A simulating circuit for simulating a toggle magnetic tunneling junction (MTJ) element includes at least a synthetic Anti-Ferromagnetic free layer, a tunnel barrier layer, and a synthetic Anti-Ferromagnetic pinned layer. The simulating circuit is configured with a converting circuit, a status circuit, a storage circuit, a voltage computing circuit and a feature simulating circuit. The convert circuit converts the magnetic filed generated from a write in current to an equivalent voltage. The status circuit indicates the flipping status of the magnetic moment of the free layer. The storage circuit is used for representing data stored in the toggle magnetic tunneling junction element. The arrangement of the magnetic moment of the two Anti-Ferromagnetic adjacent to the tunnel barrier layer is represented by the voltage computing circuit. The voltage-current characteristic is represented by the feature simulating circuit.Type: GrantFiled: February 28, 2008Date of Patent: January 25, 2011Assignee: Industrial Technology Research InstituteInventor: Young-Shying Chen
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Patent number: 7876604Abstract: Self-reference reading a magnetic tunnel junction data cell methods are disclosed. An illustrative method includes applying a read voltage across a magnetic tunnel junction data cell and forming a read current. The magnetic tunnel junction data cell has a first resistance state. The read voltage is sufficient to switch the magnetic tunnel junction data cell resistance. The method includes detecting the read current and determining if the read current remains constant during the applying step. If the read current remains constant during the applying step, then the first resistance state of the magnetic tunnel junction data cell is the resistance state that the read voltage was sufficient to switch the magnetic tunnel junction data cell to.Type: GrantFiled: February 20, 2009Date of Patent: January 25, 2011Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Yiran Chen, Xiaobin Wang, Zheng Gao, Dimitar V. Dimitrov, Wenzhong Zhu, Yong Lu
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Patent number: 7872904Abstract: A magnetic random access memory (MRAM) including multiple memory cells for forming an array is provided. Each memory cell has a magnetic free stack layer and a pinned stack layer. A magnetization of the pinned stack layer is set toward a predetermined direction. The magnetic free stack layer has a magnetic easy axis. Two magnetic easy axes of adjacent two memory cells are substantially perpendicular to each other.Type: GrantFiled: April 23, 2008Date of Patent: January 18, 2011Assignee: Industrial Technology Research InstituteInventors: Ding-Yeong Wang, Yuan-Jen Lee, Chien-Chung Hung
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Patent number: 7864564Abstract: Between the value of an electric current and the supply duration for which the electric current is supplied that cause magnetization reversal, there is the relation of monotonous decrease. This means that, as the supply duration is shortened, the threshold current value for causing the magnetization reversal is larger. Therefore, in terms of suppressing occurrence of read disturb, the read current supply duration may be shortened to increase the threshold value of the current causing the magnetization reversal and thereby ensure a sufficient read disturb margin. Therefore, the read current supply duration may be shortened relative to the write current supply duration ensure the read disturb margin and suppress occurrence of read disturb.Type: GrantFiled: December 14, 2009Date of Patent: January 4, 2011Assignee: Renesas Electronics CorporationInventor: Hideto Hidaka
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Publication number: 20100321976Abstract: A sensing circuit is disclosed. The sensing circuit includes a first path including a first resistive memory device and a second path including a reference resistive memory device. The first path is coupled to a first split path including a first load transistor and to a second split path including a second load transistor. The second path is coupled to a third split path including a third load transistor and to a fourth split path including a fourth load transistor.Type: ApplicationFiled: June 17, 2009Publication date: December 23, 2010Applicants: QUALCOMM INCORPORATED, Industry-Academic Cooperation Foundation, Yonsei UniversityInventors: Seong-Ook Jung, Jisu Kim, Seung H. Kang
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Patent number: 7855911Abstract: Spin torque magnetic logic devices that function as memory devices and that can be reconfigured or reprogrammed as desired. In some embodiments, the logic device is a single magnetic element, having a pinned layer, a free layer, and a barrier layer therebetween, or in other embodiments, the logic device has two magnetic elements in series. Two input currents can be applied through the element to configure or program the element. In use, logic input data, such as current, is passed through the programmed element, defining the resistance across the element and the resulting logic output. The magnetic logic device can be used for an all-function-in-one magnetic chip.Type: GrantFiled: May 23, 2008Date of Patent: December 21, 2010Assignee: Seagate Technology LLCInventors: Xiaohua Lou, Dimitar V. Dimitrov, Song S. Xue
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Patent number: 7852663Abstract: Spin torque magnetic logic device having at least one input element and an output element. Current is applied through the input element(s), and the resulting resistance or voltage across the output element is measured. The input element(s) include a free layer and the output element includes a free layer that is electrically connected to the free layer of the input element. The free layers of the input element and the output element may be electrically connected via magnetostatic coupling, or may be physically coupled. In some embodiments, the output element may have more than one free layer.Type: GrantFiled: May 23, 2008Date of Patent: December 14, 2010Assignee: Seagate Technology LLCInventors: Haiwen Xi, Yang Li, Song S. Xue
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Patent number: 7813202Abstract: A thin-film magnetic device comprises, on a substrate, a composite assembly deposited by cathode sputtering and consists of a first layer made of a ferromagnetic material with a high rate of spin polarization, the magnetization of which is in plane in the absence of any electric or magnetic interaction, a second layer made of a magnetic material with high perpendicular anisotropy, the magnetization of which is outside the plane of said layer in the absence of any electric or magnetic interaction, and coupling of which with said first layer induces a decrease in the effective demagnetizing field of the entire device, a third layer that is in contact with the first layer via its interface opposite to that which is common to the second layer and made of a material that is not magnetic and not polarizing for electrons passing through the device.Type: GrantFiled: August 3, 2007Date of Patent: October 12, 2010Assignees: Commissariat a l'Energie Atomique, Centre National de la Recherche ScientifiqueInventors: Bernard Rodmacq, Bernard Dieny
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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: 20100232220Abstract: Electronic devices comprise a first substrate and a second substrate. The first substrate comprises circuitry including a plurality of conductive traces at least substantially parallel to each other through at least a portion of the first substrate. A plurality of bond pads are positioned on a surface of the first substrate and comprise a width extending over at least two of the plurality of conductive traces. A plurality of vias extend from adjacent at least some of the conductive traces to the plurality of bond pads. The second substrate is bonded to the first substrate and comprises circuitry coupled to the plurality of bond pads on the first substrate with a plurality of conductive bumps. Memory devices and related methods of forming electronic devices and memory devices are also disclosed, as are electronic systems.Type: ApplicationFiled: March 10, 2009Publication date: September 16, 2010Applicant: MICRON TECHNOLOGY, INC.Inventors: Roy E. Meade, Gurtej S. Sandhu
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Patent number: 7796423Abstract: It is made possible to provide a reconfigurable logic circuit with which high integration can be achieved. A reconfigurable logic circuit includes: a multiplexer which includes a plurality of spin MOSFETs each having a source and drain containing a magnetic material, and a selecting portion including a plurality of MOSFETs and selecting a spin MOSFET from the plurality of spin MOSFETs, based on control data transmitted from control lines; a determining circuit which determines whether magnetization of the magnetic material of the source and drain of a selected spin MOSFET, which is selected by the selecting portion, is in a first state or in a second state; and a first and second write circuits which put the magnetization of the magnetic material of the source and drain of the selected spin MOSFET into the second and first states respectively by supplying a write current flowing between the source and drain of the selected spin MOSFET.Type: GrantFiled: December 19, 2008Date of Patent: September 14, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Hideyuki Sugiyama, Mizue Ishikawa, Tomoaki Inokuchi, Yoshiaki Saito, Tetsufumi Tanamoto
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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: 7751258Abstract: A magnetic random access memory includes a memory cell having a first magnetoresistive effect element, a reference cell having a second magnetoresistive effect element set in a low-resistance state, a first bit line connected to the memory cell, and set at a first bias potential in a read operation, a second bit line connected to the reference cell, and set at a second bias potential in the read operation, and a reference voltage generator including a reference current generator having a third magnetoresistive effect element set in the high-resistance state, and a current-voltage converter having a fourth magnetoresistive effect element set in the low-resistance state, the reference current generator generating a first electric current by applying the first bias potential to the third magnetoresistive effect element, and the current-voltage converter generating the second bias potential by supplying a second electric current to the fourth magnetoresistive effect element.Type: GrantFiled: October 1, 2008Date of Patent: July 6, 2010Assignee: Kabushiki Kaisha ToshibaInventor: Kenji Tsuchida
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Patent number: 7742329Abstract: Systems, circuits and methods for controlling word line voltage at a word line transistor in Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) are disclosed. A first voltage can be supplied to the word line transistor for write operations. A second voltage, which is less than the first voltage, can be supplied to the word line transistor during read operations.Type: GrantFiled: June 29, 2007Date of Patent: June 22, 2010Assignee: QUALCOMM IncorporatedInventors: Sei Seung Yoon, Seung H Kang, Medi Hamidi Sani
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Publication number: 20100142303Abstract: Circuits, apparatuses, and methods of interposing a selectable delay in reading a magnetic random access memory (MRAM) device are disclosed. In a particular embodiment, a circuit includes a sense amplifier, having a first input, a second input, and an enable input. A first amplifier coupled to an output of a magnetic resistance-based memory cell and a second amplifier coupled to a reference output of the cell also are provided. The circuit further includes a digitally-controllable amplifier coupled to a tracking circuit cell. The tracking circuit cell includes at least one element that is similar to the cell of the magnetic resistance-based memory. The first input of the sense amplifier is coupled to the first amplifier, the second input of the sense amplifier is coupled to the second amplifier, and the enable input is coupled to the third digitally-controllable amplifier via a logic circuit.Type: ApplicationFiled: December 8, 2008Publication date: June 10, 2010Applicant: QUALCOMM INCORPORATEDInventors: Dongkyu Park, Anosh B. Davierwalla, Cheng Zhong, Mohamed Hassan Soliman Abu-Rahma, Sei Seung Yoon
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Patent number: 7733692Abstract: 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: GrantFiled: June 30, 2009Date of Patent: June 8, 2010Assignee: Renesas Technology Corp.Inventor: Hideto Hidaka
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Publication number: 20100110785Abstract: Various embodiments of the present invention are generally directed to a method and apparatus for sensing a programmed state of a memory cell, such as a spin-torque transfer random access memory (STRAM) cell. A first read current is applied to the memory cell to generate a first voltage. A second read current is subsequently applied to the memory cell to generate a second voltage, with the second read current being proportional in magnitude to the first read current. A comparison is made between the first and second voltages to determine the programmed state of the memory cell.Type: ApplicationFiled: March 18, 2009Publication date: May 6, 2010Applicant: SEAGATE TECHNOLOGY LLCInventors: Yiran Chen, Hai Li, Wenzhong Zhu, Xiaobin Wang, Ran Wang, Harry Hongyue Liu
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Publication number: 20100103720Abstract: A biosensor and a sensing cell array using a biosensor are disclosed. Adjacent materials containing plurality of different ingredients are analyzed to determine the ingredients based on their magnetic susceptibility or dielectric constant. A sensing cell array includes such as a magnetization pair detection sensor including a MTJ (Magnetic Tunnel Junction) or GMR to (Giant Magnetoresistive) device, a magnetoresistive sensor including a MTJ device and a magnetic material (current line), a dielectric constant sensor including a sensing capacitor and a switching device, a magnetization hole detection sensor including a MTJ or GMR device, a current line, a free ferromagnetic layer and a switching device, and a giant magnetoresistive sensor including a GMR device, a switching device and a magnetic material (or forcing wordline).Type: ApplicationFiled: October 26, 2009Publication date: April 29, 2010Applicant: Hynix Semiconductor Inc.Inventors: Hee Bok KANG, Dong Yun Jeong, Jae Hyoung Lim, Young Jin Park, Kye Nam Lee, In Woo Jang, Seaung Suk Lee, Chang Shuk Kim
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Publication number: 20100085827Abstract: A structure comprising (i) a first information device, (ii) a second information device, (iii) a first coupling element and (iv) a second coupling element is provided. The first information device has at least a first lobe and a second lobe that are in electrical communication with each other. The second information device and has at least a first lobe and a second lobe that are in electrical communication with each other. The first coupling element inductively couples the first lobe of the first information device to the first lobe of the second information device. The second coupling element inductively couples the first lobe of the first information device to the second lobe of the second information device.Type: ApplicationFiled: October 7, 2009Publication date: April 8, 2010Applicant: D-Wave Systems, Inc.Inventors: Murray C. Thom, Andrew J. Berkley, Alexander Maassen van den Brink
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Patent number: 7688615Abstract: A magnetic random access memory (MRAM) and a manufacturing method and a programming method thereof are provided. The magnetic random access memory comprises a first magnetic tunnel junction structure and a second magnetic tunnel junction structure. The second magnetic tunnel junction structure is electrically connected with the first magnetic tunnel junction structure, and the volume of the second magnetic tunnel junction structure is smaller than that of the first magnetic tunnel junction structure.Type: GrantFiled: December 4, 2007Date of Patent: March 30, 2010Assignee: Macronix International Co., Ltd.Inventors: Chia-Hua Ho, Kuang-Yeu Hsieh
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Publication number: 20090290405Abstract: There is provided a magnetic memory device capable of reading information even with a lower power supply voltage. The magnetic memory device is equipped with a plurality of storage cells laid out in two dimensions in (i+1) rows and (j+1) columns (where i, j are integers of one or higher). Two magnetoresistive effect revealing bodies 2a, 2b are disposed in each of the storage cells 1, and each storage cell includes: a first stage circuit 41 that supplies currents Ib1, Ib2 for detecting resistances of magnetoresistive effect revealing bodies 2a, 2b; an X-direction address decoder circuit 32 that supplies currents Iw1, Iw2 to the magnetoresistive effect revealing bodies 2a, 2b; and a current control circuit (constant current circuit 25n) that carries out control so that the total of the current Ib1 and the current Iw1 and the total of the current Iw2 and the current Ib2 are respectively constant.Type: ApplicationFiled: December 7, 2005Publication date: November 26, 2009Applicant: TDK CORPORATIONInventors: Joichiro Ezaki, Yuji Kakinuma
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Patent number: 7616477Abstract: A non-volatile magnetic memory cell having a magnetic element with multiple segments which are not co-linear. Each of the segments is magnetized with a remnant magnetic field using a single write line. The segments can be magnetized in a first direction or a second direction, corresponding to first and second orientations of the memory cell. A sensor is provided to determine the direction in which the segments are magnetized and thereby the orientation of the cell. The segments are oriented such that the magnetic flux fields created by their respective remnant magnetic fields have a cumulative effect at a sensing region of the sensor. The cumulative effect allows a less sensitive sensor to be used than in known device. In various embodiments, the magnetic element can have a number of linear segments or a curved profile. In another embodiment, multiple magnetic elements are magnetized by a single write line.Type: GrantFiled: May 2, 2008Date of Patent: November 10, 2009Assignee: Micromem Technologies, Inc.Inventors: James Stephenson, Bruce Shipley, Dan Carothers
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Patent number: 7596045Abstract: A design structure embodied in a machine readable medium used in a design process includes an apparatus for initializing a reference cell in a toggle switched MRAM device, with a first sense amplifier configured for performing a first read operation of the reference cell by comparing current through the reference cell with the average current passing through a pair of data cells; a first latch for storing the result of the first read operation; a second latch for storing the result of a second read operation by the first sense amplifier, wherein the second read operation is performed following the first read operation and the inversion of the value of one of the pair of the data cells; a third latch for storing the result of a third read operation by the first sense amplifier, wherein the third read operation is performed following the second read operation and the inversion of the value of the other of the pair of the data cells; and a majority compare device configured to compare of the results of the firstType: GrantFiled: October 31, 2007Date of Patent: September 29, 2009Assignee: International Business Machines CorporationInventors: John K. DeBrosse, Mark C. H. Lamorey
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Publication number: 20090237988Abstract: A magnetic memory device includes a plurality of word lines, a plurality of bit lines arranged to intersect with the word lines, an MRAM cell array including a plurality of magnetic random access memory (MRAM) cells arranged at intersection portions between the word lines and the bit lines, a read current source which supplies a read current to the MRAM cells in a read mode, a sense amplifier which detects terminal voltages of the MRAM cells generated by the read current to generate a detection output signal, a latch circuit which latches the detection output signal to output read data, and a data write circuit which supplies a write current to the MRAM cells depending on write data in a write mode to perform writing and which supplies the write current to the MRAM cells depending on the read data in the read mode to perform rewriting.Type: ApplicationFiled: March 19, 2009Publication date: September 24, 2009Inventors: Daisuke KUROSE, Masanori Furuta, Tsutomu Sugawara
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Patent number: 7567454Abstract: 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: GrantFiled: April 11, 2008Date of Patent: July 28, 2009Assignee: Renesas Technology Corp.Inventor: Hideto Hidaka
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Publication number: 20090154229Abstract: A sensing circuit includes a sense amplifier circuit having a first and second nodes through which a magnetic memory element is sensed. A first current source is coupled to the first node a second current source is coupled to the second node. A reference magnetic memory element has a resistance associated therewith and is coupled to the first node, the reference magnetic memory element receives current from the first current source. At least one memory element, having a resistance associated therewith, is coupled to the second node and receives current from the second current source. Current from the first current source and current from the second current source are substantially the same. The logic state of the at least one memory element is sensed by a comparison of the resistance of the at least one memory element to the resistance of the reference magnetic memory element.Type: ApplicationFiled: May 22, 2008Publication date: June 18, 2009Applicant: YADAV TECHNOLOGY INC.Inventor: Parviz KESHTBOD
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Patent number: 7548450Abstract: The magnetic memory device comprises: a memory cell including two magnetoresistive effect elements serially connected to each other, and a select transistor connected to a connection node between the two magnetic resistant devices, a bit line connected to the connection node of the magnetoresistive effect elements via the select transistor, and a read circuit for reading information memorized in the magnetoresistive effect elements, based on a voltage of the connection node outputted to the bit line.Type: GrantFiled: June 18, 2007Date of Patent: June 16, 2009Assignee: Fujitsu LimitedInventor: Masaki Aoki
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Patent number: 7535783Abstract: A precision sense amplifier apparatus includes a current source configured to introduce an adjustable reference current through a reference leg; a current mirror configured to mirror the reference current to a data leg, the data leg selectively coupled to a programmable resistance memory element; an active clamping device coupled to the data leg, and configured to clamp a fixed voltage across the memory element, thereby establishing a fixed current sinking capability thereof; and a differential sense amplifier having a first input thereof coupled to the data leg and a second input thereof coupled to the reference leg; wherein an output of the differential sense amplifier assumes a first logic state whenever the reference current is less than the fixed current sinking capability of the memory element, and assumes a second logic state whenever the reference current exceeds the fixed current sinking capability.Type: GrantFiled: October 1, 2007Date of Patent: May 19, 2009Assignee: International Business Machines CorporationInventors: John K. DeBrosse, Thomas M. Maffitt, Mark C. H. Lamorey
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Patent number: 7536612Abstract: A method for monitoring field events in an MRAM memory device comprises providing a first magnetic storage cell having a switching threshold less than or equal to a switching threshold of a second magnetic storage cell, writing the first magnetic storage cell in a first direction, reading the first storage cell at a time after the writing, and determining whether the first direction has changed, and upon determining the first direction to have changed indicating a warning.Type: GrantFiled: August 29, 2003Date of Patent: May 19, 2009Assignee: International Business Machines CorporationInventors: David Abraham, Philip L. Trouilloud