Abstract: In an embodiment, a circuit is configured to produce a magnetic field signal having a frequency spectrum. The circuit may also produce a temperature signal. A modulation circuit may modulate the temperature signal with a frequency outside the frequency spectrum of the magnetic field signal. The modulated signal and the magnetic field signal may be combined to produce a combined signal. A separation circuit may be configured to separate component signals from the combined signal. The separation circuit may include a first filter, which, when applied to the combined signal, produces a filtered signal; a modulation circuit configured to shift the data representing the temperature signal to a baseband frequency; and a second filter configured to separate the data representing the temperature signal from the combined signal.

Abstract: A magnetic field sensor includes a lead frame having a plurality of leads, at least two of which have a connection portion and a die attach portion. A semiconductor die is attached to the die attach portion of the at least two leads and a separately formed ferromagnetic element, such as a magnet, is disposed adjacent to the lead frame.

Abstract: Methods and apparatus to provide a magnetic field sensor device including a magnetic sensor element, a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die, and conductive leadfingers having respective portions electrically connected to the wafer bumps. In embodiments, the device includes a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow.

Abstract: In an embodiment, a circuit is configured to produce a magnetic field signal having a frequency spectrum. The circuit may also produce a temperature signal. A modulation circuit may modulate the temperature signal with a frequency outside the frequency spectrum of the magnetic field signal. The modulated signal and the magnetic field signal may be combined to produce a combined signal. A separation circuit may be configured to separate component signals from the combined signal. The separation circuit may include a first filter, which, when applied to the combined signal, produces a filtered signal; a modulation circuit configured to shift the data representing the temperature signal to a baseband frequency; and a second filter configured to separate the data representing the temperature signal from the combined signal.

Abstract: A magnetic field sensor has a plurality of magnetic field sensing elements and operates as a motion detector for sensing a rotation or other movement of a target object.

Abstract: A system includes a magnetic target and a magnetic field sensor. The magnetic field sensor comprises an output node; a circuit to detect a magnetic field produced by the magnetic target; and a processor. The processor may be configured to transmit a signal onto the output node representing the detected magnetic field; detect whether the transmitted signal is interrupted by an external source; and, if the signal is interrupted, initiate a self-test of the apparatus. Corresponding methods and apparatuses are also disclosed.

Abstract: Methods and apparatus to provide an integrated circuit package having a conductive leadframe, a non-conductive die paddle mechanically coupled to the leadframe, and a die disposed on the die paddle and electrically connected to the leadframe. With this arrangement, eddy currents are reduced near the magnetic field transducer to reduce interference with magnetic fields.

Abstract: Methods and apparatus for a magnetic field sensor in a molded IC package having a magnetic field sensing element in a die with a component coupled to a leadframe at a downset area. In embodiments, a thickness of the leadframe in the downset area is less than a thickness of the leadframe in a non-downset area adjacent to the downset area.

Abstract: Methods and apparatus for a sensor having a die supporting a magnetic field sensor element, a leadframe having opposed first and second surfaces and leadfingers, a passive component coupled to the first and second ones of the leadfingers such that the component is an integrated part of an IC package, and a magnet adjacent to the second surface of leadframe to back bias the magnetic field sensor element.

Abstract: A magnetic field sensor includes built in self-test circuits that allow a self-test of most of, or all of, the circuitry of the magnetic field sensor, including self-test of a magnetic field sensing element used within the magnetic field sensor, while the magnetic field sensor is functioning in normal operation.

Abstract: An integrated circuit can have a first substrate supporting a magnetic field sensing element and a second substrate supporting another magnetic field sensing element. The first and second substrates can be arranged in a variety of configurations. Another integrated circuit can have a first magnetic field sensing element and second different magnetic field sensing element disposed on surfaces thereof.

Abstract: An apparatus for driving a motor comprises a drive signal generation circuit configured to produce pulses on a pulse-width modulated drive signal in response to a control signal. A detection circuit is coupled to receive a commutation signal from the motor to monitor the speed of the motor. A control signal generation circuit is configured to dynamically generate the control signal so that a frequency of pulse-width modulated drive signal corresponds with the duration of the phase of the motor, so as to reduce the occurrence of an incomplete pulse on the drive signal. Methods for driving a motor are also disclosed.

Abstract: A sensor with multiple magnetic field sensing elements for use in current sensing and other applications is presented. In one configuration, the sensor can obtain differential and absolute current measurements of current in current-carrying conductors. When employed in a ground fault interrupter (GFI) application, a first magnetic field sensing element can be used to measure the absolute current flowing in the phase conductor (phase current), a second magnetic field sensing element can be used to measure the absolute current flowing in the neutral conductor (neutral current) and a difference between the phase and neutral currents can be measured by a third magnetic field sensing element or determined from measurements of the first and second magnetic field sensing elements. In another configuration, the sensor can obtain a measure of the difference between currents and/or the sum of currents in current-carrying conductors.

Abstract: An integrated circuit can have a first substrate supporting a magnetic field sensing element and a second substrate supporting another magnetic field sensing element. The first and second substrates can be arranged in a variety of configurations. Another integrated circuit can have a first magnetic field sensing element and second different magnetic field sensing element disposed on surfaces thereof.

Abstract: Methods and apparatus for providing an integrated circuit having a drive current source, a magnetic sensing element coupled to the drive current source, the magnetic sensing element having first and second differential outputs, and first and second current elements to provide respective currents in relation to the drive current source, wherein the first current element is coupled to the first differential output and the second current element is coupled to the second differential output. In illustrative embodiments, an IC output can output a voltage corresponding to the currents of the first and second current elements.

Abstract: Methods and apparatus to provide an integrated circuit having a magnetic sensing element and fault detection module coupled to the sensing element, the fault detection module including circuitry to detect a fault condition and to self-test operation of the circuitry for detecting the fault condition. In illustrative embodiments, a fault pin indicates the fault condition.

Abstract: Methods and apparatus to provide an integrated circuit having a magnetic sensing element having differential first and second outputs and an input, the input to receive current and first and second switches coupled to a respective one of the differential first and second outputs. A first voltage source is coupled between the first and second switches, the first and second switches having a first state in which the first voltage source is coupled across the differential first and second outputs, and an IC output can output a voltage corresponding to the first voltage source when the first and second switches are in the first state for monitoring operation of a signal path from the magnetic sensing element to the IC output.

Abstract: Presented is a sensor that includes a magnetoresistive (MR) sensing device to sense a magnetic field and to produce an AC signal voltage proportional to the sensed magnetic field. The sensor also includes circuitry, coupled to the MR sensing device, to remove DC offset from the AC signal voltage. The DC offset may be related to the hysteresis characteristics of the MR sensing device. To remove DC offset, the circuitry may obtain an averaged DC offset and subtract the averaged DC offset from the AC signal voltage to produce a sensor output signal.

Abstract: An angle sensor to provide sensor-to-magnet misalignment detection and correction capability in rotation angle measurement applications is presented. The angle sensor has magnetic field sensing elements to sense magnetic field associated with a rotating magnet. The angle sensor includes circuitry to generate signals based on the sensing by the sensing elements. The signals provide information that can be combined according to an error function to provide misalignment detection. The angle sensor can be used with or can be incorporated in an angle measurement device that employs a processing unit to produce a rotation angle value. In one embodiment, the processing unit is configured to implement the error function and correct the angle value for detected misalignment. In another embodiment, the error function is performed by a programming device and detected misalignment is corrected through mechanical adjustment of sensor-to-magnet position.

Abstract: A circuit to detect a movement of an object provides a threshold selection module or a peak identifier module that uses one or more threshold signals identified prior to a present cycle of magnetic field signal in order to establish a threshold signal used for a present cycle of the magnetic field signal. A method associated with the circuit is also described. The circuit and method can be tailored to store values associated with a least common multiple of a set of possible quantities of detectable features on target objects.