Magnetic Patents (Class 327/510)
  • Patent number: 10957962
    Abstract: A magnetoresistive effect device includes an input port, an input-side signal line, an MR unit including a magnetoresistive effect element and a magnetic-field generating signal line, and an output unit including a magnetoresistive effect element, an output-side signal line, and an output port. The magnetoresistive effect device further includes a DC application terminal. The magnetoresistive effect element is connected to the output port via the output-side signal line in the output unit. The input-side signal line is arranged so that a high frequency magnetic field generated from the input-side signal line is applied to the magnetoresistive effect element in the MR unit. In the MR unit, the magnetoresistive effect element is connected to the magnetic-field generating signal line. The magnetic-field generating signal line is arranged so that a high-frequency magnetic field generated from magnetic-field generating signal line is applied to the magnetoresistive effect element in the output unit.
    Type: Grant
    Filed: October 23, 2017
    Date of Patent: March 23, 2021
    Assignee: TDK CORPORATION
    Inventors: Takekazu Yamane, Tetsuya Shibata, Tsuyoshi Suzuki, Junichiro Urabe, Atsushi Shimura
  • Patent number: 10712403
    Abstract: Electronic circuits used in magnetic field sensors use transistors for passing a current through the transistors and also through a magnetoresistance element.
    Type: Grant
    Filed: June 16, 2017
    Date of Patent: July 14, 2020
    Assignee: Allegro MicroSystems, LLC
    Inventors: Mathew Drouin, Devon Fernandez, Jay M. Towne, Alejandro Gabriel Milesi
  • Patent number: 10502586
    Abstract: A method for shielding an inductive sensor includes arranging an annular shielding coil outside an annular detection coil, the shielding coil surrounds the detection coil, and the radial thickness of the shielding coil is smaller than that of the detection coil. An inductive sensor adopting the above method for shielding the inductive sensor, in which the shielding coil is arranged outside the detection coil of the inductive sensor, magnetic fields generated by the two coils are opposite in direction and partially cancel out each other. When interference exists, the magnetic fields generated by the two coils are influenced at the same time and are attenuated or increased by identical strength. Therefore, the summed magnetic field strength can be kept constant, resonance voltages cannot be attenuated, the interference rejection of the inductive sensor is improved, and the sensitivity of the inductive sensor is not influenced.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: December 10, 2019
    Assignee: Shanghai Lanbao Sensing Technology Co., Ltd.
    Inventors: Yong Xle, Chunhua Jiang
  • Patent number: 9972380
    Abstract: Examples described in this disclosure relate to a memory cell having a magnetic Josephson junction device with a doped magnetic layer. In one example, a memory cell including a magnetic Josephson junction (MJJ) device is provided. The MJJ device may include at least a first layer formed above a second layer and a third layer formed below the second layer, where the first layer is a free magnetic layer, the second layer is a non-magnetic layer, where the third layer is a fixed magnetic layer. The free magnetic layer may comprise a magnetic alloy doped with at least one of Vanadium, Zirconium, Molybdenum, or Hafnium, and the fixed magnetic layer may comprise an un-doped second magnetic alloy.
    Type: Grant
    Filed: July 24, 2016
    Date of Patent: May 15, 2018
    Assignee: Microsoft Technology Licensing, LLC
    Inventor: Thomas F. Ambrose
  • Patent number: 9720054
    Abstract: Electronic circuits used in magnetic field sensors use transistors for passing a current through the transistors and also through a magnetoresistance element.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: August 1, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: Mathew Drouin, Devon Fernandez, Jay M. Towne, Alejandro G. Milesi
  • Patent number: 9548382
    Abstract: Provided in one embodiment is a device, comprising: a substrate; and a layer disposed over the substrate, wherein the layer comprises a monolayer of crystals comprising a Group IV element.
    Type: Grant
    Filed: October 11, 2013
    Date of Patent: January 17, 2017
    Assignees: Northeastern University, National Sun Yat-sen University, National Tsing Hua University
    Inventors: Horng-Tay Jeng, Tay-Rong Chang, Arun Bansil, Hsin Lin, Wei-Feng Tsai, Cheng-Yi Huang
  • Publication number: 20150091636
    Abstract: A method of fabricating a device includes forming a moveable plate over a substrate. The method further includes forming an energy harvesting coil in the moveable plate. The method further includes forming at least one connector connecting the movable plate with the substrate, wherein a portion of the energy harvesting coil extends along the at least one connector. The method further includes enclosing the movable plate using a capping wafer.
    Type: Application
    Filed: December 11, 2014
    Publication date: April 2, 2015
    Inventors: Tien-Kan CHUNG, Wen-Chuan TAI, Yao-Te HUANG, Hsin-Ting HUANG, Shang-Ying TSAI, Chang-Yi YANG, Chia-Ming HUNG
  • Publication number: 20150077172
    Abstract: A system and method form charge patterns on micro objects. The system and method employ a micro object including a rectifying device. The rectifying device exhibits an asymmetric current-voltage (I-V) response curve. Further, the system and method employ a device external to the micro object to induce the flow of charge through the rectifying device.
    Type: Application
    Filed: September 19, 2013
    Publication date: March 19, 2015
    Applicant: Palo Alto Research Center Incorporated
    Inventors: JengPing Lu, David K. Biegelsen, Jason Thompson
  • Patent number: 8841906
    Abstract: A current sensor having a magnetic field sensor, and a variable current source connected to the magnetic field sensor, and a first differential amplifier, connected to the magnetic field sensor, for amplifying a first sensor voltage. A second differential amplifier is provided and the second differential amplifier is connected to the first differential amplifier and to the current source. In the case of the first sensor voltage, a first operating current is present at the magnetic field sensor and in the case of a second sensor voltage, a second operating current is present, whereby the second Hall voltage is smaller than the first sensor voltage and the second operating current is greater than the first operating current.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: September 23, 2014
    Assignee: Micronas GmbH
    Inventors: Klaus Heberle, Joerg Franke
  • Patent number: 8786354
    Abstract: Embodiments relate to integrated circuits with protection. In one embodiment the protection is coupled between a first circuit provided to control a low power mode of the integrated circuit and a supply voltage. The protection comprises in an embodiment a transistor being one of a depletion transistor or a junction field effect transistor.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: July 22, 2014
    Assignee: Infineon Technologies AG
    Inventor: Mario Motz
  • Patent number: 8736343
    Abstract: A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: May 27, 2014
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey Haigh
  • Patent number: 8691407
    Abstract: A battery pack includes at least one bare cell, a protection circuit module (PCM) external to the at least one bare cell, and at least one conductive tab connecting the bare cell to the PCM, the conductive tabs including a non-magnetic portion and a magnetic portion on a region of the non-magnetic portion.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: April 8, 2014
    Assignee: Samsung SDI Co., Ltd.
    Inventor: Sung-Ho Hong
  • Patent number: 8552721
    Abstract: A Hall sensor array has two Hall sensors arranged in opposed quadrants of a two by two array. Each Hall sensor has four contacts, arranged as two pairs of opposite contacts, the axes of each pair being substantially perpendicular.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: October 8, 2013
    Assignee: Melexis Technologies NV
    Inventors: Rumen Peev, Radostin Tsankov, Stoyan Gaydov
  • Patent number: 8390362
    Abstract: Embodiments relate to an ultra-low-power, high-voltage integrated circuit (IC) that also has high electromagnetic compatibility (EMC). Embodiments address the desire for an ultra-low-power, high-voltage IC that also has high EMC and comprise a high-voltage EMC protection circuit with normal current consumption coupled to an ultra-low-power, low-voltage oscillator that controls a sleep/wake, or duty, cycle of a high-voltage circuit.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: March 5, 2013
    Assignee: Infineon Technologies AG
    Inventor: Mario Motz
  • Publication number: 20130002341
    Abstract: The input device has a printed circuit board (5) to which a plurality of coils (L1-L8) has been fitted which, together with a capacitor (C2), each form a frequency-determining element of an oscillator (1). The coils (L1-L8) are arranged so as to be distributed along a path (K), which may also be a circular path. A movable magnet portion (M) can be displaced relative to the printed circuit board (5). At least one further stationary magnet portion (M1-M8) is mounted on the printed circuit board (5), which is opposite the movable magnet portion (M).
    Type: Application
    Filed: March 22, 2011
    Publication date: January 3, 2013
    Applicant: FM MARKETING GMBH
    Inventors: Ferdinand Maier, Thomas Fischer
  • Publication number: 20110156798
    Abstract: Magnetoresistive effect elements R1 to R4 are a TMR element or CPP-GMR element. A multilayer film forming the magnetoresistive effect elements is formed to have a width dimension T1 and a length dimension L1 perpendicular to the width dimension T1. The length dimension L1 is longer than the width dimension T1. The width dimension of magnetic field generators of the coil is T2. The multilayer film 31 is positioned within the width dimension T3 of 60% in total of 30% each to the width dimension T2 of the magnetic field generators 3 and 4 of the coil in the direction towards both sides from the center of the width dimension T2 when seen in a plan view.
    Type: Application
    Filed: March 9, 2011
    Publication date: June 30, 2011
    Applicant: ALPS GREEN DEVICES CO., LTD.
    Inventors: Yosuke IDE, Masamichi SAITO, Akira TAKAHASHI, Masahiro IIZUKA, Yoshihiro NISHIYAMA, Hidekazu KOBAYASHI
  • Patent number: 7920010
    Abstract: A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: April 5, 2011
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Jr., Geoffrey Haigh
  • Publication number: 20110068853
    Abstract: A sensor for electromagnetic quantities includes a bistable device whose residence times in the stable states depend on the electromagnetic quantity. The bistable device further includes a switching zone, whose dimension in the direction of a current of charge carriers is smaller than the ballistic mean free path of the charge carriers within the switching zone. An analyzer circuit may be used for generating a sensor output signal depending on the residence times of the bistable device for measuring the electromagnetic quantity. The switching device may be a resonant tunneling diode or a Y-branch nanojunction.
    Type: Application
    Filed: August 25, 2010
    Publication date: March 24, 2011
    Applicant: JULIUS-MAXIMILIANS-UNIVERSITAT
    Inventors: Lukas Worschech, Alfred Forchel, Luca Gammaitoni
  • Publication number: 20110037512
    Abstract: A device and method for manipulating a direction of motion of current carriers are presented. The device comprises a structure containing a two-dimensional gas of current carriers configured to define at least one region of inhomogeneity which is characterized by a substantially varying value of at least one parameter from the following: a spin-orbit coupling constant, density of the spin carriers, and a mobility of the gas. The device may be configured and operable to perform spin manipulation of a flux of the spin carrying current carriers to provide at least one of the following types of deviation of said spin-carrying current carriers: spin dependent refraction, spin dependent reflection and spin dependent diffraction on desired deviation angles of a direction of motion of the spin-carrying current carriers being incident on said at least one region of inhomogeneity.
    Type: Application
    Filed: October 25, 2010
    Publication date: February 17, 2011
    Applicant: Yeda Research and Development Company Ltd.
    Inventors: Alexander FINKELSTEIN, Maxim Khodas, Arcadi Shehter
  • Patent number: 7825657
    Abstract: A magnetic field sensor comprising a sensor arrangement (H), which is supplied by a supply device (IH) and generates a sensor signal. An evaluation device (ADC, R) to which the sensor signal is fed and which outputs a first output signal (AI). A feedback device (RV) to which the first output signal is fed and which controls the supply device. The regulation of the control loop closed with the feedback device improves the noise behavior of the magnetic field sensor. A method is disclosed for operating the magnetic field sensor.
    Type: Grant
    Filed: January 11, 2005
    Date of Patent: November 2, 2010
    Assignee: Austriamicrosystems AG
    Inventors: Siegfried Rossmann, Colin Steele
  • Patent number: 7723984
    Abstract: The present invention provides a current sensor of smaller and simpler configuration, capable of measuring a current to be detected with high precision and stability. A magnetic sensor includes: an element substrate including a magnetoresistive element, the magnetoresistive element having a pinned layer with a magnetization pinned to a direction, an intermediate layer, and a free layer whose magnetization direction changes according to an external magnetic field; and a magnetic sheet attached on one side of the element substrate so as to apply a bias magnetic field to the magnetoresistive element.
    Type: Grant
    Filed: September 26, 2006
    Date of Patent: May 25, 2010
    Assignee: TDK Corporation
    Inventors: Shigeru Shoji, Masato Takahashi
  • Patent number: 7719305
    Abstract: A logic signal isolator including a micro-transformer with a primary winding and a secondary winding. A transmitter circuit drives the primary winding in response to a received input logic signal such that, in response to a first type of edge in the logic signal, at least a first amplitude signal is supplied to the primary winding and, in response to a second type of edge in the logic signal, a second different amplitude signal is supplied to the primary winding. A receiver circuit receives corresponding first amplitude and second amplitude signals from the secondary winding and reconstructs the received logic input signal from the received signals.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: May 18, 2010
    Assignee: Analog Devices, Inc.
    Inventor: Baoxing Chen
  • Patent number: 7692444
    Abstract: A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: April 6, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey Haigh
  • Patent number: 7683444
    Abstract: Materials and structures whose index of refraction can be tuned over a broad range of negative and positive values by applying above band-gap photons to a structure with a strip line element, a split ring resonator element, and a substrate, at least one of which is a photoconductive semiconductor material. Methods for switching between positive and negative values of n include applying above band-gap photons to different numbers of elements. In another embodiment, a structure includes a photoconductive semiconductor wafer, the wafer operable to receive above band-gap photons at an excitation frequency in an excitation pattern on a surface of the wafer, the excitation patterns generating an effective negative index of refraction. Methods for switching between positive and negative values of n include projecting different numbers of elements on the wafer. The resonant frequency of the structure is tuned by changing the size of the split ring resonator excitation patterns.
    Type: Grant
    Filed: November 14, 2006
    Date of Patent: March 23, 2010
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Ronald J Tonucci
  • Patent number: 7683654
    Abstract: A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: March 23, 2010
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey Haigh
  • Patent number: 7659716
    Abstract: A sensor circuit has: a sensor portion that obtains, as an electrical signal, information on an object to be measured or detected; and a control circuit that controls the operation of the sensor portion. The control circuit receives a start input signal inputted thereto from outside for making the sensor portion operate only for a given duration after the start input signal is inputted thereto. With this configuration, it is possible to reduce the current consumption by arbitrarily controlling a period of an intermittent operation of the sensor circuit.
    Type: Grant
    Filed: July 25, 2007
    Date of Patent: February 9, 2010
    Assignee: Rohm Co., Ltd.
    Inventor: Hidetoshi Nishikawa
  • Publication number: 20100007402
    Abstract: A weatherproof switch for use with an information/instrument cluster including a button having a body located adjacent to the information/instrument cluster, the body having a first end and a second end; a magnet substantially disposed within the second end of the body; a sensor located a distance from the magnet to produce a magnetic field of a first strength; and a circuit connecting the sensor to a function of the information/instrument cluster for controlling the function when the first end of the button is operated to increase and decrease the distance between the magnet and the sensor such as to produce magnetic field of a second strength.
    Type: Application
    Filed: July 10, 2008
    Publication date: January 14, 2010
    Inventors: Przemyslaw Chamuczynski, Allan Chun
  • Publication number: 20090315613
    Abstract: A semiconductor device includes a semiconductor element and a connector. The semiconductor element has a power device of a voltage drive type for controlling an on operation and an off operation of a main current by input of a drive signal. The connector receives the drive signal without making contact with an issuing unit issuing the drive signal, and transmits the drive signal to the semiconductor element. The semiconductor element preferably includes a control unit for converting the drive signal received by the connector into a voltage value, and transmitting the voltage value to the semiconductor element.
    Type: Application
    Filed: October 15, 2008
    Publication date: December 24, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Kiyoshi ARAI
  • Patent number: 7570046
    Abstract: A sensing system for a vehicle that includes a single sensor element and multiple outputs. An engine controller is responsive to the multiple outputs, output circuits and a supervisor circuit in the system monitors the sensor element and shared circuits. If the sensor element fails, or if a connector fails or if the supervisor circuit indicates a circuit failure, one or more of the outputs will go outside of their normal operating range into a diagnostics range to allow the engine controller to take the appropriate action.
    Type: Grant
    Filed: October 14, 2003
    Date of Patent: August 4, 2009
    Assignee: BorgWarner Inc.
    Inventors: Robert D. Keefover, Todd Peterson, John W. Duddles
  • Patent number: 7521927
    Abstract: A magnetic induction switching circuit comprising a magnetic induction device for sensing a magnetic field and generating signals corresponding to the polarity of the field. A detection control unit detects the signals generated in response to a magnetic field and configures a programmable switching unit so that the first signal generated in response to a detected magnetic field having a first polarity is coupled through the switching unit and subsequent signals generated in response to detecting different polarity magnetic fields are not coupled through the switching unit.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: April 21, 2009
    Assignee: Anachip Corporation
    Inventors: Ming Hua Ku, Ching Hsieng Lee
  • Publication number: 20090051408
    Abstract: Provided is a switch for vehicles, which includes an intermittent driving device connected to a control device which opens and closes a switching device based on the magnitude of the magnetism of a magnet mounted on an operating body. Therefore, the supply of power from a battery to a detection device and the control device is intermittently performed at a predetermined period by the intermittent driving device.
    Type: Application
    Filed: July 21, 2008
    Publication date: February 26, 2009
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaru Shimizu, Kiyotaka Sasanouchi
  • Publication number: 20090051409
    Abstract: Provided is a switch for vehicles, including a first switching device which performs the electrical connection/disconnection between a battery and a stop lamp and a second switching device connected to a control device which opens and closes the first switching device based on the magnitude of the magnetism of a magnet mounted on an operating body. Various controls such as auto-cruise control and so on as well as the turn on/off of the stop lamp can be simultaneously performed by the one magnet mounted on the operating body of the switch for vehicles.
    Type: Application
    Filed: July 21, 2008
    Publication date: February 26, 2009
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaru Shimizu, Kiyotaka Sasanouchi
  • Publication number: 20090009233
    Abstract: A method (500), a handheld electronic device (102) and an external accessory (402) for controlling at least one function of a plurality of functions of the handheld electronic device is provided. The method includes determining (504) whether the handheld electronic device is docked in an external accessory. Further, the method includes measuring (506) a first magnetic field density when the handheld electronic device is docked in the external accessory. Furthermore, the method includes generating (508) a signal to activate at least one function, based on an electrical parameter.
    Type: Application
    Filed: July 3, 2007
    Publication date: January 8, 2009
    Applicant: MOTOROLA, INC.
    Inventors: Dhaval N. Shah, Peter B. Gilmore, Timothy M. Bergin, Manish W. Mahajan
  • Patent number: 7075329
    Abstract: A logic signal isolator comprising a transformer having a primary winding and a secondary winding; a transmitter circuit which drives said primary winding in response to a received logic signal, such that in response to a first type of edge in the logic signal, a signal of a first predetermined type is supplied to the primary winding and in response to a second type of edge in the logic signal, a signal of a second predetermined type is supplied to said primary winding, the primary winding and the transmitter being referenced to a first ground; and the secondary winding being referenced to a second ground which is galvanically isolated from the first ground and said secondary winding supplying to a receiver circuit signals received in correspondence to the signals provided to the primary winding, the receiver reconstructing the received logic signal from the received signals.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: July 11, 2006
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey Haigh
  • Patent number: 7064538
    Abstract: A system and methods for an interface for magnetic sensors to determine a rotational angle has been achieved. This interface can be used for magnetic sensors providing analog signals of the sine and cosine values of the angle to be determined. Analog signals are being processed in two measurement paths for the sine and cosine signal each until the desired angle is computed by a CORDIC processor. The first stage of the measurement path is the conversion of the sine and cosine signals from analog to digital by 2nd order delta-sigma modulators with an over-sampling ratio. A low-pass decimation filter with sinc3 characteristic performs the digital value computation. The next stage normalizes the digitized sine and cosine values to correct offset and scaling deviations.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: June 20, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventor: Juergen Kernhof
  • Patent number: 6850058
    Abstract: The invention provides an offset and low frequency noise insensitive magnetic sensor which incorporates a magnetic field effect transistors (MagFETs). Methods of improving the signal to noise ratio and reducing errors from offsets when measuring magnetic fields using MagFETs are also described. The invention also provides for the use of such methods and sensor in circuitry adapted to provide for residual current detection.
    Type: Grant
    Filed: May 6, 2002
    Date of Patent: February 1, 2005
    Assignee: University College Cork-National University of Ireland
    Inventor: John Doyle
  • Patent number: 6657476
    Abstract: A method and apparatus for minimizing errors in a sensor device due to signal amplitude variation are disclosed herein. A signal output from the sensor device is amplified and, thereafter, AC-coupled to a comparator such that the amplification and AC-coupling of the signal minimize offset shift-related errors associated with the sensor device. The signal can be coupled to eliminate offset shifts due to component mismatches, calibration, aging and/or temperature associated with the sensor device. An AC-coupled sensor signal conditioning circuit is utilized to amplify the signal through an amplifier and then AC-couple the signal to a comparator.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: December 2, 2003
    Assignee: Honeywell International Inc.
    Inventor: Robert E. Bicking
  • Patent number: 6534969
    Abstract: In a device for measuring an angle &phgr; between a magnetic field and an MR sensor (1) which supplies at least two electrical sensor signals x and y mutually 90° phase-shifted, which are supplied to an A/D converter (4) whose output is connected to an angle calculating device (6), the absolute sensor signal value |r| of the two sensor signals x and y is determined from the equation |r|={square root over (y2+x2)} in a total calculation device (7) for the purpose of an automatic and continuous offset compensation of the static and dynamic offsets, and the change in the absolute sensor signal value is determined therefrom in dependence on the calculated angle, whereupon an offset control of the sensor signals x and y is carried out in dependence on said change in absolute value.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: March 18, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Klaus Dietmayer
  • Publication number: 20020093332
    Abstract: A circuit and method of providing desired response from magnetic field sensors to a predetermined magnetic function. Typically, magnetic field sensors, such as magnetoresistive devices and Hall effect sensors, provide an output which is a characteristic function of the magnetic field density, and so they do not generate a linear response in relation to any predetermined magnetic function, such as is required within numerous position or angle resolving circuits. The present invention utilizes two or more magnetically sensitive devices to tailor the overall sensor output signal to any desired function of the magnetic field density. The devices are connected in such a way that they mutually effect each other's voltages or currents to render the final desired output characteristic.
    Type: Application
    Filed: January 18, 2001
    Publication date: July 18, 2002
    Inventors: Thaddeus Schroeder, Dale Lee Partin, Joseph Pierre Heremans
  • Patent number: 6297673
    Abstract: The evaluation circuit has a current interface (1,1′; 11,11′) for a current signal (i2) from an electronic signal transducer (6,6′; 16,16′); a current-sensing FET (3,3′; 13,13′) having a gate (G), a source (S), a drain (D) and a sensing output (sense), which is connected so that the current signal from the transducer passes through the source and drain; a monitoring circuit (5,5′; 15,15′) for controlling the current-sensing FET in the event of a malfunction connected between the gate (G) and to the drain (D) or source (S); a current reflector circuit (4,4′; 14,14′) having an input connected to the sensing output (sense) of the current-sensing FET and a resistor (2,2′; 12,12′) for converting current to voltage, which is connected to an output of the current reflector circuit, so that the current signal is converted to a voltage signal tapped between the resistor and the current reflector circuit.
    Type: Grant
    Filed: November 17, 1999
    Date of Patent: October 2, 2001
    Assignee: Robert Bosch GmbH
    Inventor: Michael Walther
  • Patent number: 6208176
    Abstract: An adaptive driver circuit which uses a modified conventional current mirror circuit to provide a current source employing an automatically adjustable current to compensate for decreased SMR device sensitivity at higher temperatures and large air gaps without the need for an active feedback circuit. The adaptive driver circuit according to the present invention is a unique modification of a current mirror circuit in that an SMR device is used as the reference resistor and a fixed resistor in the mirrored circuit to generate an output voltage. A modification is also possible whereby two adaptive driver circuits are used in a differential mode.
    Type: Grant
    Filed: September 17, 1998
    Date of Patent: March 27, 2001
    Assignee: General Motors Corporation
    Inventors: Thaddeus Schroeder, Joseph Pierre Heremans
  • Patent number: 6191576
    Abstract: A geartooth sensor utilizes an algorithm for establishing an adaptive threshold for the switch point of the sensor to minimize drift in the point at which the sensor output changes in relation to the target features it is tracking. The algorithm utilizes measured waveform peak and average outputs and applies a separate empirically derived constant to each value to quickly obtain the major portion of the adaptive threshold value from the product of the first constant and the peak output, and to refine the threshold value further with the product of the second constant and the average output.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: February 20, 2001
    Assignee: Honeywell Inc.
    Inventors: Lamar F. Ricks, Wayne A. Lamb, Peter G. Hancock
  • Patent number: 6183859
    Abstract: A low resistance magnetic tunnel junction with low resistance barrier layer and method of fabrication is disclosed. A first magnetic layer of material with a surface is provided and a continuous layer of material, e.g. aluminum, is formed on the surface of the first magnetic layer. The continuous layer of material is treated to produce a low resistance barrier layer of oxynitride material and a second magnetic layer is formed on the barrier layer of oxynitride material to complete the low resistance magnetic tunnel junction.
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: February 6, 2001
    Assignee: Motorola, Inc
    Inventors: Eugene Chen, Jon Slaughter, Renu Whig
  • Patent number: 6160322
    Abstract: A pulse signal generator comprises a magnetic element capable of causing a large Barkhausen jump, a detector provided in relation to the magnetic element, a magnetic field source provided in the vicinity of the magnetic element to produce a biasing magnetic field which causes a predetermined magnetization of the magnetic element, and a magnetic circuit forming member provided in the vicinity of the magnetic element to produce a main magnetic field which cause a large Barkhausen jump in the magnetic element such that movement of the object to be detected changes the main magnetic field of the magnetic circuit forming member thereby causing a large Barkhausen jump to provide a pulse signal.
    Type: Grant
    Filed: September 10, 1998
    Date of Patent: December 12, 2000
    Assignee: Hirose Electric Co., Ltd.
    Inventors: Akihiro Gotoh, Shoji Oyama, Tomoaki Ito
  • Patent number: 6097129
    Abstract: An electronically commutated external rotor motor has an external rotor having a cup-shaped housing and a radially magnetized permanent magnet connected in the cup-shaped housing. An interior stator is positioned in the cup-shaped housing. The interior stator has a laminated core having grooves. Windings are provided within the grooves. The windings have first end turns proximal to a bottom of the cup-shaped housing and second end turns positioned distal to the bottom. The first and second end turns electrically connect the windings to one another. The permanent magnet has an end face remote from the bottom of the cup-shaped housing. At least one galvano-magnetic rotor position sensor is arranged opposite the end face of the permanent magnet so as to be located within a magnetic leakage of the permanent magnet and within a magnetic leakage of the interior stator. The at least one rotor position sensor is designed to control current within at least a portion of the windings.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: August 1, 2000
    Assignee: Papst-Motoren GmbH & Co. KG
    Inventors: Patrick Furtwangler, Hermann Rappenecker, Harald Reich, Gabor Szondi
  • Patent number: 6087882
    Abstract: An isolator having a driver circuit which is responsive to an input signal to drive signals into a magnetic-field generator such as at least one coil. The generator is magnetically coupled to a sensor that includes spin-valve resistors which have resistance characteristics that are variable in response to the magnetic field generated by the generator. A receiver circuit incorporating a strobe generator converts the resistance changes to an output signal corresponding to the input signal.
    Type: Grant
    Filed: December 4, 1998
    Date of Patent: July 11, 2000
    Assignee: Analog Devices, Inc.
    Inventors: Baoxing Chen, Geoffrey T. Haigh, Alberto G. Comaschi
  • Patent number: 5952824
    Abstract: A magnetic detecting apparatus is capable of performing accurate waveform processing without being affected by noise signals or the like, the level shifting circuit thereof having a fixed voltage shift so as to be free of varying amplitudes of analog signals. Waveform shaping circuitry for turning an analog signal detected from a giant magnetoresistive element into a pulse signal includes: the level shifting circuit for generating an amplified voltage (V1) of analog signals and a voltage (V2) which is higher than the voltage (V1) and a voltage (V3) which is lower than the voltage (V1); a circuit which alternately retains the minimum value of the voltage (V2) and the maximum value of the voltage (V3) as a reference voltage; and a comparator circuit which compares a voltage resulting from adding a hysteresis to the voltage (V1) with the reference voltage and issues a pulse signal.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: September 14, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Izuru Shinjo, Yasuyoshi Hatazawa, Naoki Hiraoka, Yutaka Ohashi
  • Patent number: 5801533
    Abstract: Cascode coupled magnetic field effect transistors used to measure magnetic field. The disclosed cascode coupled MagFET circuit includes cascode coupled transistors used to equalize the voltage at the drains of the MagFET resulting in a differential Hall current. The cascode devices are biased at a state of very weak inversion to maximize input impedance. The differential currents are amplified with an active current mirror load coupled to the cascode configured devices. A comparator is used to sense the differential currents. The reference voltages used to bias the MagFET and the cascode coupled devices are generated with a bias network including a MagFET precisely matched with the MagFET used to measure the magnetic field such that the magnetic field measuring circuit is exceptionally immune to variations in process, temperature and supply voltage.
    Type: Grant
    Filed: September 17, 1996
    Date of Patent: September 1, 1998
    Assignee: Intel Corporation
    Inventor: Jeffrey C. Kalb, Jr.
  • Patent number: 5760581
    Abstract: A circuit including daisy chain coupled triple drain magneto field effect transistors (MagFETs) for measuring magnetic field. The disclosed method and apparatus describe multiple MagFETs coupled together to accumulate voltage differentials generated in response to magnetic field. A lateral drain of a first triple drain MagFET is used to bias the gate of a second triple drain MagFET. The center drains and sources of each MagFET are biased with well matched current sources which permit the center drains and sources of each MagFET to float to a corresponding voltage biasing each triple drain MagFET near threshold. With the gate of each MagFET biased by a lateral drain of a prior MagFET, and with the source of each MagFET permitted to float to approximately a threshold voltage less than the corresponding gate voltage, the generated voltage differentials by each MagFET are accumulated thereby resulting in increased sensitivity to magnetic field.
    Type: Grant
    Filed: September 17, 1996
    Date of Patent: June 2, 1998
    Assignee: Intel Corporation
    Inventor: Jeffrey C. Kalb, Jr.
  • Patent number: 5744950
    Abstract: A sensor for determining the rotational speed of a rotating element. The sensor includes a giant magnetoresistive ratio sensing device which is magnetically coupled to the rotating element and includes an output terminal. The sensing device generates an output signal at the output terminal having a frequency corresponding to the rotational speed of the rotating element. A wave-shaping circuit is connected to the output terminal for receiving the output signal and for generating a digital switching signal having a frequency equal to the frequency of the output signal. A frequency divider has an input connected to the wave shaping circuit for receiving the digital switching signal. The frequency divider generates, in response to the digital switching signal, a square wave output having a 50% duty cycle and a frequency equal to the frequency of the digital switching signal divided by a predetermined divisor.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: April 28, 1998
    Assignee: SSI Technologies, Inc.
    Inventor: James D. Seefeldt