Abstract: The present invention relates to a hall electromotive force signal detection circuit and a current sensor thereof each of which is able to achieve excellent wide-band characteristics and fast response as well as high accuracy. A difference calculation circuit samples a component synchronous with a chopper clock generated by a chopper clock generation circuit, out of an output voltage signal of a signal amplifier circuit, at a timing obtained from the chopper clock, so as to detect the component. An integrating circuit integrates an output from the difference calculation circuit in the time domain. An output voltage signal from the integrating circuit is fed back to a signal amplifier circuit via a third transconductance element.

Abstract: A position sensor comprises at least one magneto-sensitive element, a current source that is coupled to the at least one magneto-sensitive element and is configured to supply a source current to the at least one magneto-sensitive element, an analog-to-digital converter having an input coupled to the at least one magneto-sensitive element, a position calculation unit that is coupled to an output of the analog-to-digital converter and comprises a first output for providing a position signal, and a diagnostic unit that comprises an output coupled to the current source and is configured to provide a stimulus signal as a function of a stimulus pattern at the output of the diagnostic unit.

Abstract: A method of sensing a current in a conductor includes controlling a digital to analog converter output to cancel residual offset voltage in a magnetic tunnel junction device prior to sensing the current with the magnetic tunnel junction device. The method includes switching input to the magnetic tunnel junction device between a fixed voltage and an output of a digital to analog converter while switching input to a band pass filter between a lower and an upper voltage output of the magnetic tunnel junction device. The output of the digital to analog converter is modified to provide a low-amplitude unsaturated sine-wave at an output of the band pass filter, at which point changes in the output of the band pass filter are associated with the amount of current in a sensed conductor.

Abstract: There is provided a position detection device to suppress an influence of a signal distortion due to a processing error or the like, the position detection device including: a reference position calculation unit that calculates a reference position of a moving body on the basis of a first signal and a second signal, the first signal being detected from a first track provided on the moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles; a slit specifying unit that specifies a slit corresponding to a position of the moving body; an in-slit position calculation unit that calculates an in-slit position of the moving body in the specified slit; and a correction unit that corrects an absolute position of the moving body.

Abstract: Inductive position sensors for sensing relative position (e.g., relative rotary position) between members are provided. In one example implementation, the inductive position sensor includes a transmit aerial having at least one transmit winding. The inductive position sensor can include a receive aerial having one or more receive windings. The inductive position sensor can include a coupling element operable to be disposed on the second member. The inductive position sensor can include processing circuitry configured to provide one or more signals indicative of the position of the first member relative to the second member based on current induced in the one or more receive windings resulting from an oscillating signal provided to the transmit winding. The inductive position sensor includes at least one electrostatic shield. The electrostatic shield can include a plurality of conductive traces arranged so that no current loops are formed in the electrostatic shield.

Abstract: Magnetic field sensor apparatuses are discussed. A magnetic field sensor apparatus in accordance with one example implementation in this case comprises a coil and a magnetic field sensor. A chip carrying the coil and the magnetic field sensor is arranged on a leadframe. The leadframe comprises a cutout.

Abstract: A magnetic field sensor includes a lead frame, a passive component, semiconductor die supporting a magnetic field sensing element and attached to the lead frame, a non-conductive mold material enclosing the die and at least a portion of the lead frame, and a ferromagnetic mold material secured to a portion of the non-conductive mold material. The lead frame has a recessed region and the passive component is positioned in the recessed region. The ferromagnetic mold material may comprise a soft ferromagnetic material to form a concentrator or a hard ferromagnetic material to form a bias magnet.

Abstract: A downhole borehole imaging tool and methods for determining a borehole size includes a magnetoresistive system and a hub moveably coupled to a fixed tool string. The hub includes a magnet. The magnetoresistive system includes magnetoresistive sensors disposed within the fixed tool string and segregated from the magnet. During operation, a routine scan of all sensors measures, for example, the output voltage V, angle ? of magnetic field, and temperature. Measurements from each sensor may then be characterized to account for temperature and input voltages variation of the sensors. The most accurate measurement can be used to derive the position of the hub 44 using the previous baseline parameters stored in the tool.

Abstract: A magnetic field sensor includes at least one coil responsive to an AC coil drive signal; at least one magnetic field sensing element responsive to a sensing element drive signal and configured to detect a directly coupled magnetic field generated by the at least one coil and to generate a magnetic field signal in response to the directly coupled magnetic field; a processor responsive to the magnetic field signal to compute a sensitivity value associated with detection of the directly coupled magnetic field and substantially independent of a reflected magnetic field reflected by a conductive target disposed proximate to the at least one magnetic field sensing element; and an output signal generator configured to generate an output signal of the magnetic field sensor indicative of the reflected magnetic field.

Abstract: A magnetism detection apparatus includes a detection device, at least one first locating device, and a central control device. The detection device includes an array of detection assemblies arranged in a same plane. The array of detection assemblies is configured to detect magnetic fields and output magnetic field signals corresponding to locations of the detection assemblies. The at least one first locating device is disposed on one of the detection assemblies to locate this detection assembly and output a first coordinate signal corresponding to this detection assembly. The central control device is communicatively and respectively connected to each of the detection assemblies and the at least one first locating device, and configured to process the magnetic field signals and the first coordinate signal.

Abstract: An apparatus and a method provide an output signal indicative of a speed of rotation and/or a direction of movement of a ferromagnetic object. The sensor includes at least one magnetic field sensing element configured to generate a magnetic field signal in response to a magnetic field associated with an object. The sensor includes a detector configured to generate a detector signal having edges occurring in response to a comparison of the magnetic field signal and the threshold signal. The sensor includes an output circuit configured to generate an output signal having a first format when a characteristic of the magnetic field signal is within a first range and having a second format different than the first format when the characteristic of the magnetic field signal is within a second range, different than the first range.

Abstract: Hall sensing signals are received in a spinning readout pattern of subsequent readout phases, wherein the pattern is cyclically repeated at a spinning frequency and a polarity of the Hall sensor signals is reversed in two non-adjacent readout phases of the readout pattern. A signal storage circuit includes signal storage capacitors. An accumulation circuit includes accumulation capacitors. A switch network is selectively actuated to couple the signal storage capacitors with the accumulation capacitors synchronously with phases in the spinning readout pattern in subsequent alternating first and second periods. The spinning output is stored with alternating opposite signs on the signal storage capacitors and the Hall sensing signals are stored in the signal storage capacitors and then accumulated on the accumulation capacitors with alternate signs in subsequent periods. The accumulated output signal is then demodulated with a demodulation frequency half the spinning frequency.

Abstract: A magnetic field measurement apparatus including a magnetic sensor array having magnetic sensor cells capable of detecting magnetic fields in three axial directions arranged in three dimensions, each magnetic sensor cell including a plurality of magnetic sensors that each have a magnetoresistive element and a magnetic flux concentrator arranged at least at one of one end and another end of the magnetoresistive element; AD converters that respectively convert analog detection signals output by the magnetic sensors into digital measurement data; a magnetic field acquiring section that acquires the digital measurement data; a calibration computing section that calibrates the digital measurement data from the magnetic field acquiring section, using at least one of a main-axis sensitivity, cross-axis sensitivities, and an offset; and a gradient magnetic field computing section that calculates a gradient magnetic field using magnetic field measurement data resulting from the calibration of the digital measurement d

Abstract: A system includes a magnetic sensor that can store a magnetic state associated with a number of accumulated turns of a magnetic target. The magnetic sensor may work in conjunction with a magnetic target. The magnetic target may produce a magnetic field that, at some positions, drops below a magnetic window of the magnetic sensor. The magnetic target may produce a magnetic field that is within the magnetic window when needed to update the magnetic state of the sensor to keep track of the accumulated turns of the magnetic target. The magnetic sensor may be initialized with one or more domain walls.

Abstract: An object of the present invention is to reduce leakage magnetic flux in a magnetic sensor provided with a sensor substrate and an external magnetic member. A magnetic sensor includes: a sensor substrate having an element forming surface on which magnetic sensing elements are formed, first and second side surfaces, and a back surface; a first external magnetic member provided between the first and second magnetic sensing elements; and a second external magnetic member having first and second parts and covering the first side surface and second side surface, respectively. The first and second parts of the second external magnetic member protrude from the element forming surface. According to the present invention, since the first and second parts of the second external magnetic member protrude from the element forming surface, leakage of magnetic flux between the first and second external magnetic members is reduced.

Abstract: A probe for measuring a cathodic protection condition of a buried steel structure includes: a steel electrode; a reference electrode; and a coupon fabricated of a conductive material. The steel electrode, the reference electrode and the conductive coupon are positioned in an ionically conductive medium in proximity with each other and are isolated from direct electrical contact with each other.

Abstract: Inductive position sensors for sensing relative position (e.g., relative rotary position) between members are provided. In one example implementation, the inductive position sensor includes a transmit aerial having at least one transmit winding. The inductive position sensor can include a receive aerial having one or more receive windings. The inductive position sensor can include a coupling element operable to be disposed on the second member. The inductive position sensor can include processing circuitry configured to provide one or more signals indicative of the position of the first member relative to the second member based on current induced in the one or more receive windings resulting from an oscillating signal provided to the transmit winding. The inductive position sensor includes at least one electrostatic shield. The electrostatic shield can include a plurality of conductive traces arranged so that no current loops are formed in the electrostatic shield.

Abstract: A sensor cross-talk compensation system includes a semiconductor substrate having a first main surface and a second main surface opposite to the first main surface; a vertical Hall sensor element disposed in the semiconductor substrate, the vertical Hall sensor element is configured to generate a sensor signal in response to a magnetic field impinging thereon; and an asymmetry detector configured to detect an asymmetric characteristic of the vertical Hall sensor element. The asymmetry detector includes a detector main region that vertically extends into the semiconductor substrate from the first main surface towards the second main surface and is of a conductivity type having a first doping concentration; and at least three detector contacts disposed in the detector main region at the first main surface, the at least three detector contacts are ohmic contacts of the conductivity type having a second doping concentration that is higher than the first doping concentration.

Abstract: A current sensing system, comprising at least one magnetic tunnel junction device placed adjacent to a current carrying conductor electrically connected to a battery of a vehicle. The magnetic tunnel junction device is configured to measure a magnetic field around the conductor. A monitoring device is operatively connected to the magnetic tunnel junction device, wherein the monitoring device is configured to receive the magnetic field measurement and determine an estimate of the current flowing through the conductor.

Abstract: A magnetoresistive Z-axis gradient sensor chip, which is used to detect the gradient in the XY plane of a Z-axis magnetic field component generated by a magnetic medium; the sensor chip comprises a Si substrate, a collection of two or two groups of flux guide devices separated a distance Lg and an arrangement of electrically interconnected magnetoresistive sensor units. The magnetoresistive sensor units are located on the Si substrate and located above or below the edge of the flux guide devices as well; the flux guide devices convert the component of the Z-axis magnetic field into the direction parallel to the surface of the Si substrate along the sensing axis direction of the magnetoresistive sensing units. The magnetoresistive sensor units are electrically interconnected into a half bridge or a full bridge gradiometer arrangement, wherein the opposite bridge arms are separated by distance Lg. This sensor chip can be utilized with a PCB or in combination with a PCB plus back-bias magnet with casing.