Abstract: A magnetic field sensor includes a phase-locked loop to receive a measured magnetic field signal formed from sensing element output signals of a plurality of magnetic field sensing elements in response to a magnetic field. The phase-locked loop is configured to generate an angle signal having a value indicative of the angle of the magnetic field. Associated methods are also described.

Abstract: In one aspect, an electronic device includes a switching circuit connected to a resistance circuit and ground, the resistance circuit connected to a port and the port configured to be connected in series to an external resistor and a supply voltage. A voltage at the port is a first voltage that is less than the supply voltage if the switching circuit is enabled to be a closed circuit and the voltage at the port is a second voltage that is equal to the supply voltage if the switching circuit is enabled to be an open circuit.

Abstract: Methods and apparatus for controlling a three-phase motor and providing sinusoidal phase currents during startup. In embodiments, differential outputs from a magnetic field sensing element are used to generate a polarity signal used to provide a motor direction drive signal. An amplitude signal derived from the magnetic field sensing element and a measured motor current are used to generate a current amplitude signal. A PWM module generates signals for driving the motor with sinusoidal phase currents from the current amplitude signal and the motor direction drive signal.

Abstract: A filter circuit includes a filter having an input and an output at which an output of the filter is provided, a step detector coupled to receive an input signal at the input of the filter and configured to detect a predetermined step in the input signal and to assert a bypass signal in response to detection of the predetermined step. A logic circuit is responsive to the bypass signal and configured to cause the input signal to be coupled to the output of the filter without filtering when the bypass signal is asserted.

Abstract: A magnetic field sensor can include four magnetoresistance elements arranged in a bridge, wherein two of the magnetoresistance elements have a response to an external or stray magnetic field that is opposite to a response of the other two magnetoresistance elements.

Abstract: A magnetic field sensor for sensing an absolute position of a target object can include a first one or more magnetic field sensing elements disposed proximate to a first portion of the target object, the first one or more magnetic field sensing elements operable to generate a first magnetic field signal responsive to the movement of the first portion; a second one or more magnetic field sensing elements disposed proximate to a second portion of the target object, the second one or more magnetic field sensing elements operable to generate a second magnetic field signal responsive to the movement of the second portion; a position detection module coupled to use the first and second magnetic field signals to generate a position value indicative of the absolute position; and an output format module coupled to receive the position value and to generate a position signal from the magnetic field sensor indicative of the absolute position.

Abstract: A sensor is provided to include: a sampling clock circuit generating a sample clock signal with a predetermined sample clock period; a system clock circuit generating a system clock signal with a predetermined system clock period, wherein a value of the system clock period is less than a value of the sample clock period; a sensor circuit generating, during each sample clock period, a sensor signal representing a position of an object; a sampling circuit receiving the sensor signal and generate sample signal value in response; an interpolation circuit determining a first difference between a current sample signal and a previous sample signal, determining a second difference between a switchpoint threshold value and the previous sample signal, and determining a delay count based upon a ratio of the first difference and the second difference; and a switchpoint signal circuit generating a switchpoint signal based upon the delay count.

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.

Abstract: A magnetic field sensor includes a first magnetic field sensing element configured to generate a first magnetic field signal indicative of a magnetic field associated with a target, a second magnetic field sensing element spaced from the first magnetic field sensing element and configured to generate a second magnetic field signal indicative of the magnetic field associated with the target. A switching module coupled to receive the first and second magnetic field signals is configured to generate a combined signal having alternating portions associated with the first and second magnetic field signals.

Abstract: A system for reducing stray field effects comprises a magnetic target producing a changing magnetic field; a first set of magnetic field sensing elements placed in spaced relation to the magnetic target and comprising at least a first magnetic field sensing element and a second magnetic field sensing element, each magnetic field sensing element having an axis of maximum sensitivity; a second set of magnetic field sensing elements placed in spaced relation to the magnetic target and comprising at least a third magnetic field sensing element and a fourth magnetic field sensing element, each magnetic field sensing element having an axis of maximum sensitivity; and wherein the first set of magnetic field sensing elements is positioned closer to a center point of the magnetic field than the second set of magnetic field sensing elements.

Abstract: A manufacturing method results in a magnetoresistance element having conductive contacts disposed between the magnetoresistance element and a semiconductor substrate.

Abstract: Methods and apparatus for a signal isolator having reduced parasitics. An example embodiment, a signal isolator and include a first metal region electrically connected to a first die portion, a second die portion isolated from the first die portion, and a second metal region electrically connected to the second die portion. A third metal region can be electrically isolated from the first and second metal regions and a third die portion can be electrically isolated from the first, second and third metal regions. In embodiments, the first metal region, the second metal region, and the third metal region provide a first isolated signal path from the first die portion to the second die portion.

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: A circuit includes a first amplifier having first and second inputs and first and second output, first and second input capacitors, a first feedback capacitor selectively coupled between the first input and the first output, and a second feedback capacitor selectively coupled between the second input and the second output. During a second phase of operation, the first and second feedback capacitors are decoupled from the output and the first amplifier is configured to sample an input common mode voltage, an output common mode voltage, and an input offset voltage of the first amplifier on the first and second input capacitors. During a first phase of operation, the first feedback capacitor is coupled between the input and the output, the second feedback capacitor is coupled between the input and the output, and the first amplifier is configured to amplify a differential input signal provided across the first and second inputs.

Abstract: Methods and apparatus for a sensor having a first magnetic field sensing element with first and second segments where the first and second segments are located at positions of opposite magnetic field. The first and second segments are spaced from each other based upon iso-lines of the magnetic field. A processing module can process an output of the magnetic field sensing element.

Abstract: A joystick assembly for use with a device including a joystick surface and a first magnet having north and south magnetic poles includes a second magnet having north and south magnetic poles and a movable elongated shaft having first and second opposing ends arranged along a major axis of the shaft. The first end of the shaft is coupled to the second magnet such that movement of the shaft results in movement of the second magnet relative to the first magnet such that a line between centers of the north and south magnetic poles of the second magnet is movable relative to a line between the north and south magnetic poles of the first magnet. An attraction of the second magnet to the first magnet results in a restoring force upon the shaft, and the shaft and the second magnet are removable from the joystick surface.

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 magnetic field sensor that detects an angle of a target includes a first channel having first and second magnetic field sensing elements that are orthogonal with respect to each other and produce first and second magnetic field signals, and a second channel having third and fourth magnetic field sensing elements that are orthogonal with respect to each other and produce third and fourth magnetic field signals. The third sensing element is positioned at an angle (e.g., 45-degrees) with respect to the first sensing element. The magnetic field sensor includes a low power mode circuit that uses comparators to compare the first, second, third, and fourth magnetic field signals to a first, second, third, and fourth threshold, respectively. A processor is configured to use an output of the low power mode circuit to determine the angle of the target.

Abstract: A magnetoresistance element structure disposed parallel to an x-y plane defined by an x-axis and a y-axis orthogonal to the x-axis can include a first magnetoresistance element having a plurality of first shapes coupled in series to result in the first magnetoresistance element having a first serpentine shape parallel to the x-y plane; and a second magnetoresistance element having a plurality of second shapes coupled in series to result in the second magnetoresistance element having a second serpentine shape parallel to the x-y plane, wherein the plurality of first shapes and the plurality of second shapes are disposed in an interdigitated pattern. A magnetic field sensor can use the above magnetoresistance element structure. Nested magnetoresistance elements and magnetic field sensors are also described.

Abstract: A magnetic field sensor includes one or more magnetic field sensing elements configured to generate a magnetic field signal responsive to a magnetic field and a detector coupled to receive an interpolated threshold and a signal representative of the magnetic field signal, wherein the detector is configured to compare the interpolated threshold with the signal representative of the magnetic field signal to generate a detector output signal. A memory is configured to store a first threshold value indicative of a threshold value at a first temperature and a second threshold value indicative of a threshold value at a second temperature lower than the first temperature and a threshold module coupled to the memory and configured to generate the interpolated threshold based on the stored first and second threshold values.