Patents by Inventor Dimitar Dimitrov

Dimitar Dimitrov has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8400867
    Abstract: A method and apparatus for stray magnetic field compensation in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a first tunneling barrier is coupled to a reference structure that has a perpendicular anisotropy and a first magnetization direction. A recording structure that has a perpendicular anisotropy is coupled to the first tunneling barrier and a nonmagnetic spacer layer. A compensation layer that has a perpendicular anisotropy and a second magnetization direction in substantial opposition to the first magnetization direction is coupled to the nonmagnetic spacer layer. Further, the memory cell is programmable to a selected resistance state with application of a current to the recording structure.
    Type: Grant
    Filed: December 12, 2011
    Date of Patent: March 19, 2013
    Assignee: Seagate Technology LLC
    Inventors: Dimitar Dimitrov, Olle Gunnar Heinonen, Dexin Wang, Haiwen Xi
  • Publication number: 20120143928
    Abstract: Various embodiments of systems and methods for file system transaction log flush optimization are described herein. An optimizer is working as an intelligent processing unit, autonomously determining the best possible time to flush all collected transaction data modifications to the file system when operating under high load, or flushing each modification separately under low load. When operating under high load, batches of data modifications are collected and written together to the file system in a single write operation, thus decreasing the number of write operations and achieving better utilization of the system resources.
    Type: Application
    Filed: December 7, 2010
    Publication date: June 7, 2012
    Inventors: FILIP YANKOV, DIMITAR DIMITROV, Vania Slavchova Dimitrova, Ivan Dimitrov Dimitrov, NIKOLAI TANKOV
  • Patent number: 8098541
    Abstract: A method and apparatus for stray magnetic field compensation in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a first tunneling barrier is coupled to a reference structure that has a perpendicular anisotropy and a first magnetization direction. A recording structure that has a perpendicular anisotropy is coupled to the first tunneling barrier and a nonmagnetic spacer layer. A compensation layer that has a perpendicular anisotropy and a second magnetization direction in substantial opposition to the first magnetization direction is coupled to the nonmagnetic spacer layer. Further, the memory cell is programmable to a selected resistance state with application of a current to the recording structure.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: January 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Dimitar Dimitrov, Olle Gunnar Heinonen, Dexin Wang, Haiwen Xi
  • Publication number: 20110310513
    Abstract: An apparatus includes a magnetoresistive read element, first and second primary shields, and an auxiliary shield. The magnetoresistive read element is located between the first and the second primary shields, and the auxiliary shield is located between the magnetoresistive read element and the first primary shield. In another embodiment, the apparatus includes a plurality of magnets located between a plurality of shields for a magnetoresistive element. The plurality of magnets is optionally offset from the magnetoresistive element.
    Type: Application
    Filed: June 16, 2010
    Publication date: December 22, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Dimitar Dimitrov, Dion Song
  • Publication number: 20110213273
    Abstract: According to certain described aspects, multiple acoustic sensing elements are employed in a variety of beneficial ways to provide improved physiological monitoring, among other advantages. In various embodiments, sensing elements can be advantageously employed in a single sensor package, in multiple sensor packages, and at a variety of other strategic locations in the monitoring environment. According to other aspects, to compensate for skin elasticity and attachment variability, an acoustic sensor support is provided that includes one or more pressure equalization pathways. The pathways can provide an air-flow channel from the cavity defined by the sensing elements and frame to the ambient air pressure.
    Type: Application
    Filed: October 14, 2010
    Publication date: September 1, 2011
    Inventors: Valery G. Telfort, Dimitar Dimitrov, Phi Trang, Massi Joe E. Kiani, Anand Sampath
  • Publication number: 20110213271
    Abstract: According to certain described aspects, multiple acoustic sensing elements are employed in a variety of beneficial ways to provide improved physiological monitoring, among other advantages. In various embodiments, sensing elements can be advantageously employed in a single sensor package, in multiple sensor packages, and at a variety of other strategic locations in the monitoring environment. According to other aspects, to compensate for skin elasticity and attachment variability, an acoustic sensor support is provided that includes one or more pressure equalization pathways. The pathways can provide an air-flow channel from the cavity defined by the sensing elements and frame to the ambient air pressure.
    Type: Application
    Filed: October 14, 2010
    Publication date: September 1, 2011
    Inventors: Valery G. Telfort, Dimitar Dimitrov, Phi Trang
  • Patent number: 7998758
    Abstract: A magnetic element and a method for making a magnetic element. The method includes patterning a first electrode material to form a first electrode on a substrate and depositing filler material on the substrate around the first electrode. The method further includes polishing to form a planar surface of filler and the first electrode. A magnetic cell is formed on the planar surface and a second electrode is formed on the magnetic cell. In some embodiments, the first electrode has an area that is at least 2:1 to the area of the magnetic cell.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: August 16, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yongchul Ahn, Shuiyuan Haung, Antoine Khoueir, Paul Anderson, Lili Jia, Christina Laura Hutchinson, Ivan Ivanov, Dimitar Dimitrov
  • Publication number: 20110194337
    Abstract: A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified.
    Type: Application
    Filed: April 21, 2011
    Publication date: August 11, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tian, Brian Seungwhan Lee
  • Patent number: 7940600
    Abstract: A method and apparatus for stray magnetic field compensation in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a first tunneling barrier is coupled to a reference structure that has a perpendicular anisotropy and a first magnetization direction. A recording structure that has a perpendicular anisotropy is coupled to the first tunneling barrier and a nonmagnetic spacer layer. A compensation layer that has a perpendicular anisotropy and a second magnetization direction in substantial opposition to the first magnetization direction is coupled to the nonmagnetic spacer layer. Further, the memory cell is programmable to a selected resistance state with application of a current to the recording structure.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: May 10, 2011
    Assignee: Seagate Technology LLC
    Inventors: Dimitar Dimitrov, Olle Gunnar Heinonen, Dexin Wang, Haiwen Xi
  • Patent number: 7936592
    Abstract: A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tan, Brian Seungwhan Lee
  • Publication number: 20110069536
    Abstract: 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: Application
    Filed: November 30, 2010
    Publication date: March 24, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaohua Lou, Dimitar Dimitrov, Song Xue
  • Publication number: 20100309717
    Abstract: Non-volatile multi-bit memory with programmable capacitance is disclosed. Illustrative data memory units include a substrate including a source region and a drain region; and a gate stack structure over the substrate and between the source region and drain region. The gate stack structure includes a first solid electrolyte cell and a second solid electrolyte cell. The solid electrolyte cells having a capacitance that is controllable between at least two states. A gate contact layer is electrically coupled to a voltage source. The first solid electrolyte cell and the second solid electrolyte cell separate the gate contact layer from the substrate.
    Type: Application
    Filed: August 17, 2010
    Publication date: December 9, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xuguang Wang, Shuiyuan Huang, Dimitar Dimitrov, Michael Tang, Song Xue
  • Publication number: 20100274099
    Abstract: An acoustic sensor is configured to provide accurate and robust measurement of bodily sounds under a variety of conditions, such as in noisy environments or in situations in which stress, strain, or movement may be imparted onto a sensor with respect to a patient. Embodiments of the sensor provide a conformable electrical shielding, as well as improved acoustic and mechanical coupling between the sensor and the measurement site.
    Type: Application
    Filed: December 21, 2009
    Publication date: October 28, 2010
    Applicant: MASIMO Corporation
    Inventors: Valery G. Telfort, Predrag Pudar, Dimitar Dimitrov, Phi Trang, Ammar Al-Ali
  • Publication number: 20100195380
    Abstract: A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified.
    Type: Application
    Filed: February 3, 2009
    Publication date: August 5, 2010
    Applicant: Seagate Technology LLC
    Inventors: Xiaobin Wang, Yong Lu, Haiwen Xi, Yuankai Zheng, Yiran Chen, Harry Hongyue Liu, Dimitar Dimitrov, Wei Tian, Brian Seungwhan Lee
  • Publication number: 20100109110
    Abstract: Magnetic spin-torque memory cells, often referred to as magnetic tunnel junction cells, which have magnetic anisotropies (i.e., magnetization orientation at zero field and zero current) of the associated ferromagnetic layers aligned perpendicular to the wafer plane, or “out-of-plane”. A memory cell may have a ferromagnetic free layer, a first pinned reference layer and a second pinned reference layer, each having a magnetic anisotropy perpendicular to the substrate. The free layer has a magnetization orientation perpendicular to the substrate that is switchable by spin torque from a first orientation to an opposite second orientation.
    Type: Application
    Filed: March 5, 2009
    Publication date: May 6, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Dexin Wang, Haiwen Xi, Yuankai Zheng, Dimitar Dimitrov
  • Publication number: 20100109107
    Abstract: A magnetic element and a method for making a magnetic element. The method includes patterning a first electrode material to form a first electrode on a substrate and depositing filler material on the substrate around the first electrode. The method further includes polishing to form a planar surface of filler and the first electrode. A magnetic cell is formed on the planar surface and a second electrode is formed on the magnetic cell. In some embodiments, the first electrode has an area that is at least 2:1 to the area of the magnetic cell.
    Type: Application
    Filed: February 20, 2009
    Publication date: May 6, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yongchul Ahn, Shuiyuan Huang, Antoine Khoueir, Paul Anderson, Lili Jia, Christina Laura Hutchinson, Ivan Ivanov, Dimitar Dimitrov
  • Publication number: 20090289240
    Abstract: Non-volatile multi-bit memory with programmable capacitance is disclosed. Illustrative data memory units include a substrate including a source region and a drain region. A first insulating layer is over the substrate. A first solid electrolyte cell is over the insulating layer and has a capacitance that is controllable between at least two states and is proximate the source region. A second solid electrolyte cell is over the insulating layer and has a capacitance or resistance that is controllable between at least two states and is proximate the drain region. An insulating element isolates the first solid electrolyte cell from the second solid electrolyte cell. A first anode is electrically coupled to the first solid electrolyte cell. The first solid electrolyte cell is between the anode and the insulating layer. A second anode is electrically coupled to the second solid electrolyte cell. The second solid electrolyte cell is between the anode and the insulating layer.
    Type: Application
    Filed: May 20, 2008
    Publication date: November 26, 2009
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xuguang Wang, Shuiyuan Huang, Dimitar Dimitrov, Michael Tang, Song Xue
  • Publication number: 20090290408
    Abstract: 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: Application
    Filed: May 23, 2008
    Publication date: November 26, 2009
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Xiaohua Lou, Dimitar Dimitrov, Song Xue
  • Publication number: 20050063100
    Abstract: A magnetic sensor having adjustable electrical dimensions, such as electrical read width and electrical stripe height, is disclosed. The magnetic sensor includes a sensor stack with one or more bias electrodes positioned with respect to the sensor stack. The electrical width or electrical stripe height of the sensor stack is a function of a voltage applied to the bias electrodes. The electric field produced by the bias electrodes alters the electrical profile of the magnetoresistive device.
    Type: Application
    Filed: September 23, 2003
    Publication date: March 24, 2005
    Applicant: Seagate Technology LLC
    Inventors: Michael Kautzky, David Larson, Bradley Miller, Erick Singleton, Dimitar Dimitrov, Eric Granstrom, Song Xue
  • Patent number: 6700752
    Abstract: A read/write head with a bottom shield on a slider substrate and a shared shield spaced apart from the bottom shield. A write head is deposited on the shared shield. A read sensor is spaced apart by reader magnetic gaps from the bottom shield and the shared shield. Electrically insulating layers in the reader magnetic gaps form a thermal resistance between the read sensor and the shields. A thermally conducting nonmagnetic layer in a reader magnetic gap reduces the thermal resistance without a corresponding reduction in the reader magnetic gaps.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: March 2, 2004
    Assignee: Seagate Technology LLC
    Inventors: Dimitar Dimitrov, Michael C. Kautzky, Sunita B. Gangopadhyay, Jumna P. Ramdular, Sisavath M. Bounnakhom, I-Fei Tsu, Robert W. Lamberton