Abstract: In one aspect, bridge circuitry includes a first magnetoresistance (MR) element; a second MR element connected in series with the first MR element at a first node; a third MR element; a fourth MR element connected in series with the third MR element at a second node; a first switch connected at one end to a supply voltage and connected at the other end to the third MR element; a second switch connected at one end to ground and connected at the other end to the fourth MR element; a third switch connected at one end to ground and connected at the other end to the third MR element and the first switch; and a fourth switch connected at one end to the supply voltage and the other end to the fourth MR element and the second switch. The first and second MR elements are in parallel with the third and fourth MR elements.

Abstract: A magnetic field sensor for detecting motion of an object includes one or more magnetic field sensing elements configured to generate a magnetic field signal in response to a magnetic field associated with the motion of the object and a detector responsive to the magnetic field signal and to a threshold signal and configured to generate a comparison signal having edges occurring in response to a comparison of the magnetic field signal to the threshold signal. A threshold generator is configured to generate the threshold signal at a first level when a peak-to-peak value of the magnetic field signal is greater than a first predetermined value and at a second level when the peak-to-peak value of the magnetic field signal is less than a second predetermined value different than the first predetermined value.

Abstract: Methods and apparatus for a magnetic field sensor having first and second arrays of magnetic field sensing elements with at least first and second orthogonal axes of sensitivity. The first array of magnetic field sensing elements is spaced a first distance from the second array of magnetic field sensing elements. A turns counter counts a number of times a magnetic pole pair of a moving target passes the magnetic field sensing elements with a selected pole pair resolution and a module determines absolute angular position of the target from differential signals from the first and second arrays of magnetic field sensing elements and the turns counter. The first distance is configured to match a pitch of the poles of the target.

Abstract: Methods and apparatus for a controlling a stimulus source to direct photons to a pixel in a pixel array contained in a detector system, analyzing a response of the pixel in the pixel array; and generating an alert based on the response of the pixel in the pixel array. Example stimulus sources include a conductive trace, a PN junction, and a current source.

Abstract: Methods and apparatus for determining and transmitting speed and/or direction information for a rotating target by a magnetic field sensor. A reference channel signal is generated for a target from at least one magnetic field sensing element and a virtual channel signal in quadrature with the reference channel signal is generated. A tangent signal is generated. A slope of an arctangent of the tangent signal is determined, wherein the slope corresponds to rotational speed of the target. The speed and/or direction of the target can be transmitted by a sensor IC.

Abstract: A sensor interface includes a signal path configured to receive a sensing element output signal from a sensing element and to generate an interface output signal indicative of a parameter sensed by the sensing element, an NTC interface and a diode interface. The NTC interface is configured to be coupled to an NTC element having a non-linear resistance over temperature and to generate an NTC signal indicative of a linearized version of the non-linear resistance of the NTC element and the diode interface configured to be coupled to a diode and to generate a diode signal indicative of an absolute temperature.

Abstract: Methods and apparatus for a controlling a stimulus source to direct photons to a pixel in a pixel array contained in a detector system, analyzing a response of the pixel in the pixel array; and generating an alert based on the response of the pixel in the pixel array. Example stimulus sources include a conductive trace, a PN junction, and a current source.

Abstract: A magnetic field sensor includes a lead frame, a semiconductor die, a conductive coil, a mandrel, and a non-conductive mold material. The lead frame has a first surface, a second opposing surface, at least one slot, and a plurality of leads. The semiconductor die has a first surface in which a magnetic field sensing element is disposed and a second opposing surface attached to the first surface of the lead frame. The conductive coil is secured to the second surface of the lead frame and configured to operate as a back bias magnet to provide a magnetic field used to detect movement of a target. The coil is would around the mandrel and the mandrel is comprised of a ferromagnetic material. The non-conductive mold material encloses the die, the conductive coil, the mandrel, and at least a portion of the lead frame.

Abstract: According to some embodiments, a device includes: a magnetic field current sensor magnetically coupled to a conductor and configured to generate a magnetic field signal having a magnitude responsive to a current flowing through the conductor; a shunt interface having first and second input terminals electrically coupled to ends of a shunt disposed along the conductor, the shunt interface configured to generate a shunt signal having a magnitude responsive to the current flowing through the conductor; and a diagnostic circuit configured to receive the magnetic field signal and the shunt signal and to generate a fault signal based on a comparison between the magnitude of the magnetic field signal and the magnitude of the shunt signal.

Abstract: An interface circuit for a position sensor system including an oscillator generating an oscillation signal having a carrier frequency and a primary phase, a primary coil responsive to the oscillation signal, and a secondary coil electromagnetically coupled to the primary coil by a target and configured to generate a secondary signal having the carrier frequency and a secondary phase provides phase compensation.

Abstract: A magnetic field sensor includes: a substrate; a transmission coil formed on the substrate, the transmission coil being configured to generate a direct magnetic field; a sensing bridge that is formed on the substrate, the sensing bridge being configured to detect the direct magnetic field and a reflected magnetic field that is generated by a target, the reflected magnetic field being generated in response to eddy currents that are induced in the target by the direct magnetic field; a processing circuitry being configured to generate an output signal that is indicative of a position of the target, the output signal being generated by normalizing a first signal with respect to a second signal, the first signal being generated at least in part by using the sensing bridge, and the second signal being generated at least in part by using the sensing bridge, wherein the second signal is based on the detected direct magnetic field.

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 sensor integrated circuit including a regulator for generating a regulated voltage includes a digital load configured to draw a load current from the regulator in response to a clock signal during in situ operation and a comparator configured to determine the absence or presence of a fault during in situ operation. The load current is less than or equal to a predetermined level in the absence of a fault and is greater than the predetermined level in the presence of a fault. The comparator is responsive to the load current and to a threshold level and is configured to generate a comparator output signal having a level indicative of whether the load current is less than or greater than the threshold level in order to thereby determine the absence or presence of a fault during in situ operation, respectively.

Abstract: In one aspect, a bridge includes a first magnetoresistance element having a first reference angle; a second magnetoresistance element in series with the first magnetoresistance element and having a second reference angle; a third magnetoresistance element in parallel with the first magnetoresistance element and having the first reference angle; and a fourth magnetoresistance element in series with the third magnetoresistance element and having the second reference angle. An output of the bridge has a linear response over a range of horizontal magnetic field values having non-zero values and the range of horizontal magnetic field intensity values are associated with vertical magnetic field intensity values having zero Oersted (Oe) values. A reference angle indicates an angle the magnetoresistance element is most sensitive to changes in a magnetic field.

Abstract: A magnetic field sensor includes a current source configured to generate a bias current, a plurality of magnetic field transducers, each having power terminals coupled to the current source and output terminals at which an output signal of the transducer is provided, wherein the power terminals of each of the plurality of magnetic field transducers are electrically coupled together in series so that the bias current flows through each of the plurality of magnetic field transducers in series. A capacitively-coupled summing amplifier has a plurality of inputs, each configured to receive the output signal of a respective one of the plurality of magnetic field transducers, and an output at which an amplified and summed signal is provided, wherein the capacitively-coupled summing amplifier is configured to amplify and sum the received output signals of the plurality of magnetic field transducers.

Abstract: In one aspect, a linear sensor includes at least one magnetoresistance element that includes a first spin valve and a second spin valve positioned on the first spin valve. The first spin valve includes a first set of reference layers having a magnetization direction in a first direction and a first set of free layers having a magnetization direction in a second direction orthogonal to the first direction. The second spin valve includes a second set of reference layers having a magnetization direction in the first direction and a second set of free layers having a magnetization direction in a third direction orthogonal to the first direction and antiparallel to the second direction. The first direction is neither parallel nor antiparallel to a direction of an expected magnetic field.

Abstract: A sensor including: a substrate having a first region and a second region; a first series of first magnetoresistive (MR) elements formed on the substrate, the first series of first MR elements including at least two first MR elements; and a second series of second MR elements that is coupled in parallel with the first series of first MR elements to form a bridge circuit, the second series of second MR elements being formed on the substrate, the second series of second MR elements including at least two second MR elements, each of the at least two second MR elements having a different pinning direction than each of the at least two first MR elements, wherein one of the at least two first MR elements and one of the at least two second MR elements are formed in the first region of the substrate and have different pinning directions.

Abstract: A motor control system for controlling operation of a motor having a plurality of windings includes a gate driver to provide a control signal to one or more switching elements controlling a voltage applied to the plurality of windings and a Field Oriented Control (FOC) controller configured to generate a PWM signal for coupling to the gate driver, wherein the FOC controller comprises a d-axis control loop configured to generate an applied d-axis voltage and a q-axis control loop configured to generate an applied q-axis voltage. A stall detector is configured to calculate an estimate of the q-axis voltage and compare the applied q-axis voltage to a threshold based on the estimate in order to detect a stall condition of the motor.

Abstract: A magnetic field sensor is provided with improved stress compensation accounting for temperature. The magnetic field sensor includes a stress sensing, element, a temperature sensing element, a magnetic field sensing element, a memory, and an electronic circuitry. The memory is configured to store a first table. The first table identities a plurality of stress-to-sensitivity coefficients. Each of the plurality of stress-to-sensitivity coefficients is mapped to a different temperature value. The electronic circuitry is configured to use a temperature reading and a stress reading to calculate a stress difference between an expected stress and the stress reading.

Abstract: Methods and apparatus for measuring a current difference between at least two primary current paths in a current sensor integrated circuit package. Each primary current path generated a magnetic field which may then be measured by at least one magnetic field sensing element positioned on an integrated circuit die. An output disconnect signal may be provided from the current sensor integrated circuit package when a current difference above a predetermined threshold exists in the two or more current traces.