Abstract: A sensor system and method use channel information to generate redundant angle measurements for sensing rotation of magnets about a given axis of rotation. It was observed that magnetic field strength on a circle, centered on the axis of rotation but in a plane perpendicular to it, have a component parallel to the axis that varies sinusoidally as a function of the angle around the circle. By placing magnetic field sensors equiangularly around such a circle, and summing their field strengths with appropriate weights, the angle of magnet rotation may be computed in a manner that is immune to the presence of stray fields. Moreover, fewer than all channels of sense data may be combined to form redundant estimates of the angle of rotation, to permit continued operation when one of the sensors has failed.

Abstract: Methods and apparatus for determining a mechanical angle of a target from sine and cosine signals generated by inductive sensing elements by applying harmonic compensation on the sine and cosine signals using possible mechanical angles and analyzing results of the applied harmonic compensation. One of the mechanical angles can be selected based on the results of the applied harmonic compensation. In embodiments, a cost function can be used to select the mechanical angle.

Abstract: Methods and apparatus that can include a rotatable target to generate a sinusoidal signal in a magnetic field sensor, wherein the target includes a plurality of sinusoidal teeth to reduce angular error. A magnetic field sensor can be configured to determine a position of the target. In embodiments, a rotatable target to generate a sinusoidal signal in a magnetic field sensor can include a plurality of sinusoidal teeth and a number of harmonics to reduce angular error.

Abstract: A motor control system includes a gate driver motor controller and a microcontroller configured to generate a commutation command signal for coupling to the gate driver motor controller. The gate driver motor controller includes a current measurement circuit to measure current in each of three current paths corresponding to three motor windings, an interface to transmit a first subset of the measured currents corresponding to a first subset of the current paths, and a calibrator to calibrate a current path that is not part of the first subset of current paths when the first subset of the measured currents is transmitted. The microcontroller includes an interface to receive the first subset of measured currents and a processor to compute the current in the current path that is not part of the first subset of current paths based on the first subset of measured currents.

Abstract: Systems, methods, and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally, one or more IDDQ and/or built-in-self test (BIST) circuits may be included.

Abstract: A sensor system and method use channel information to generate redundant angle measurements for sensing rotation of magnets about a given axis of rotation. It was observed that magnetic field strength on a circle, centered on the axis of rotation but in a plane perpendicular to it, have a component parallel to the axis that varies sinusoidally as a function of the angle around the circle. By placing magnetic field sensors equiangularly around such a circle, and summing their field strengths with appropriate weights, the angle of magnet rotation may be computed in a manner that is immune to the presence of stray fields. Moreover, fewer than all channels of sense data may be combined to form redundant estimates of the angle of rotation, to permit continued operation when one of the sensors has failed.

Abstract: Methods and apparatus for an orientation insensitive speed sensor. Magnetic field sensing elements can be located on a circle, for example, to generate first and second channel signals which can be combined to generate an output signal. The location of the magnetic field sensing elements reduces the effects of stray fields. Embodiments can include true power own state processing to determine target position during start up.

Abstract: In one aspect, a system includes an electronic control unit (ECU) and an integrated circuit (IC). The IC is configured to transmit, to the ECU, absolute data on a message line at a first rate; and transmit, to the ECU, incremental data on an index line at a second rate. The second rate is faster than the first rate and the incremental data includes data associated with changes in the absolute data.

Abstract: Methods and apparatus for determining a mechanical angle of a target from sine and cosine signals generated by inductive sensing elements by applying harmonic compensation on the sine and cosine signals using possible mechanical angles and analyzing results of the applied harmonic compensation. One of the mechanical angles can be selected based on the results of the applied harmonic compensation. In embodiments, a cost function can be used to select the mechanical angle.

Abstract: In one aspect, a system includes an electronic control unit (ECU) and an integrated circuit (IC). The IC is configured to transmit, to the ECU, absolute data on a message line at a first rate; and transmit, to the ECU, incremental data on an index line at a second rate. The second rate is faster than the first rate and the incremental data includes data associated with changes in the absolute data.

Abstract: In some embodiments, a method can include receiving, by an angle sensor, a first periodic angle signal indicative of an angle of a first magnetic field associated with a first track of a target; receiving, by the angle sensor, a second periodic angle signal indicative of an angle of a second magnetic field associated with a second track of the target; generating an uncorrected absolute angle signal indicative of an absolute angle of the target based on the first and second periodic angle signals; determining an estimated error associated with the uncorrected absolute angle signal based on the first periodic angle signal and the second periodic signal; subtracting the estimated error from the uncorrected absolute angle to generate a corrected absolute angle signal; and providing the corrected absolute angle signal as output of the angle sensor.

Abstract: Methods and apparatus that can include a rotatable target to generate a sinusoidal signal in a magnetic field sensor, wherein the target includes a plurality of sinusoidal teeth to reduce angular error. A magnetic field sensor can be configured to determine a position of the target. In embodiments, a rotatable target to generate a sinusoidal signal in a magnetic field sensor can include a plurality of sinusoidal teeth and a number of harmonics to reduce angular error.

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 object and a detector configured to generate a comparison signal having edges occurring in response to a comparison of the magnetic field signal and a threshold signal and occurring at a rate corresponding to a speed of motion of the object. A speed monitor responsive to the comparison signal is configured to generate a speed signal having a value indicative of the speed of motion of the object.

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 object and a detector configured to generate a comparison signal having edges occurring in response to a comparison of the magnetic field signal and a threshold signal and occurring at a rate corresponding to a speed of motion of the object. A speed monitor responsive to the comparison signal is configured to generate a speed signal having a value indicative of the speed of motion of the object.

Abstract: An apparatus is provided, comprising: a plurality of terminals for coupling the apparatus to a sensing bridge; a switching circuitry that is coupled to at least one of the plurality of terminals; and a processing circuitry that is configured to: cause the switching circuitry to couple the plurality of terminals to a voltage source, a ground source, and the processing circuitry in accordance with a first connection profile; detect a failure of the sensing bridge or a connection between the sensing bridge and any of the plurality of terminals; select a second connection profile based on a type of the failure; and cause the switching circuitry to couple the plurality of terminals to the voltage source, the ground source, and the processing circuitry in accordance with the second connection profile.

Abstract: Methods and apparatus for a magnetic field sensor for measuring movement of a target including a substrate and a magnet. A first bridge structure has first and second pluralities of magnetic field sensing elements spaced from each other. An axis of sensitivity of the magnetic field sensing elements is rotated at a predetermined angle with respect to an axis of rotation of the target to generate an output signal corresponding to the position of the target and a change in a property of the magnetic field generated by the magnet.

Abstract: Methods and apparatus for an orientation insensitive speed sensor. Magnetic field sensing elements can be located on a circle, for example, to generate first and second channel signals which can be combined to generate an output signal. The location of the magnetic field sensing elements reduces the effects of stray fields. Embodiments can include true power own state processing to determine target position during start up.

Abstract: A magnetic field sensor includes one or more magnetic field sensing elements and a back-biased magnet arranged to avoid saturation of the one or more magnetic field sensing elements, particularly when the one or more magnetic field sensing elements comprise one or more magnetoresistance elements. The one or more magnetoresistance elements can be arranged in a resistor bridge.

Abstract: In some embodiments, a method can include receiving, by an angle sensor, a first periodic angle signal indicative of an angle of a first magnetic field associated with a first track of a target; receiving, by the angle sensor, a second periodic angle signal indicative of an angle of a second magnetic field associated with a second track of the target; generating an uncorrected absolute angle signal indicative of an absolute angle of the target based on the first and second periodic angle signals; determining an estimated error associated with the uncorrected absolute angle signal based on the first periodic angle signal and the second periodic signal; subtracting the estimated error from the uncorrected absolute angle to generate a corrected absolute angle signal; and providing the corrected absolute angle signal as output of the angle sensor.

Abstract: A magnetic field sensor includes a plurality of magnetic field sensing elements configured to generate at least two measured magnetic field signals indicative of a magnetic field affected by an object and having a first predetermined phase difference with respect to each other and a controller responsive to the at least two measured magnetic field signals. The controller is configured to generate an angle signal and to compare the angle signal to at least one angle signal threshold. The angle signal can be compared to a plurality of angle signal thresholds to generate a plurality of output transitions, each output transitions indicative of the angle signal crossing the corresponding angle signal threshold. The number of angle signal thresholds can be dependent upon a desired number of output transitions per pole-pair of the angle signal.