Abstract: A variety of magnetic field sensor arrangements provide so-called “tooth detectors” using a simple low-cost magnet.

Abstract: A magnetic field sensor provides an angle error value to correct errors of the magnetic field sensor. The angle error value is a function of temperature and magnetic field strength and is used to correct a measured magnetic field angle. Associated methods are also described.

Abstract: Methods and apparatus for detecting a magnetic field include a magnetic source configured to provide a magnetic field to induce an eddy current in a non-ferromagnetic target, and a magnetic field sensing element configured to detect the magnetic field as a result of the eddy current. The magnetic field provided by the magnetic source can be a static (i.e. DC) field or a changing (i.e. non-DC) field.

Abstract: An integrated circuit includes circuitry to sense the occurrence of a break in a ground connection and/or supply connection and to indicate same to an exterior environment. In at least one implementation, the break may be indicated by providing a signal on an output terminal of the device that is not associated with a normal output of the device.

Abstract: A power clamp circuit having improved robustness to electrostatic discharge (ESD) events includes a voltage regulation circuit and a current controlled switch. The voltage regulation circuit and the current controlled switch may be used to modify a snapback voltage of the power clamp in a manner that enhances the power clamp's ability to handle ESD events.

Abstract: A magnetic field sensor includes a circular vertical Hall (CVH) sensing element and at least one planar Hall element. The CVH sensing element has contacts arranged over a common implant region in a substrate. In some embodiments, the at least one planar Hall element is formed as a circular planar Hall (CPH) sensing element also having contacts disposed over the common implant region. A CPH sensing element and a method of fabricating the CPH sensing element are separately described.

Abstract: A magnetic field sensor and associated method provide an output signal with an identifiable encoding to indicate when a signature region in a moving target proximate to the magnetic field sensor passes by the magnetic field sensor.

Abstract: A motor control circuit and associated techniques detect a zero crossing of a current in a motor winding by detecting a reverse current in a half bridge circuit used to drive the motor winding.

Abstract: A motor control circuit and associated techniques can adjust a phase of a motor drive to keep a rotational reference position of an electric motor at the same relative phase as a zero current in a motor winding at different motor speeds and as the motor accelerates and decelerates. In some embodiments, a particular circuit and technique can be used to detect the zero current in the motor winding.

Abstract: A current sensor packaged in an integrated circuit package to include a magnetic field sensing circuit, a current conductor and an insulator that meets the safety isolation requirements for reinforced insulation under the UL 60950-1 Standard is presented. The insulator is provided as an insulation structure having at least two layers of thin sheet material. The insulation structure is dimensioned so that plastic material forming a molded plastic body of the package provides a reinforced insulation. According to one embodiment, the insulation structure has two layers of insulating tape. Each insulating tape layer includes a polyimide film and adhesive. The insulation structure and the molded plastic body can be constructed to achieve at least a 500 VRMS working voltage rating.

Abstract: A closed loop current sensor has a primary conductor and a plurality of secondary conductors. Selected ones of the plurality of secondary conductors are selected and driven in a feedback loop.

Abstract: A system for controlling a motor may include a motor driver circuit for driving a camera motor. A memory capable of storing a plurality of parameters for controlling the camera motor may also be included. A set of parameters from the memory may be chosen to be applied to driving the motor. A motor control module may receive a signal from the control logic module, apply the chosen set of parameters to driving the camera motor, and command the motor driver circuit to drive the motor in accordance with the applied set of parameters. The parameters may be chosen based on desired behavior of the system and various other stimuli.

Abstract: A magnetic field sensor includes first, second, and third magnetic field sensing elements having respective first, second and third maximum response axes, the first second and third maximum response axes pointing along respective first, second, and third different coordinate axes. In response to a magnetic field, the first, second, and third magnetic field sensing elements are operable to generate first second, and third magnetic field signals. Signals representative of the first, second, and third magnetic field signals are compared with thresholds to determine if the magnetic field is greater than the thresholds. A corresponding method is also provided.

Abstract: A sensor with multiple magnetic field sensing elements for use in current sensing and other applications is presented. The sensor includes an arrangement of two or more magnetic field sensing elements to sense magnetic field associated with a target. The sensor further includes circuitry to generate a sensor output signal based on sensing of at least one of the magnetic field sensing elements of the arrangement. Also included is a programmable misalignment adjustment block to control the circuitry to generate the output signal with compensation for misalignment between the sensor and the target. The programmable misalignment adjustment block can be programmed to select measurement of one of the two or more magnetic field sensing elements, or alternatively, a mathematical combination of measurements of the two or more magnetic field sensing elements, for generating the sensor output signal when a test of the sensor indicates a misalignment.

Abstract: A motor control circuit and associated techniques can drive an electric motor in a start-up mode of operation followed by a normal mode of operation. The motor control circuit and techniques can receive a selection signal provided by a user that can select one of a plurality of sets of parameter values that determine characteristics of drive signals applied to the motor during the start-up mode of operation. The motor control circuit and associated techniques can synchronize operation between the start-up mode of operation and the normal mode of operation.

Abstract: A motor control circuit and associated techniques can drive an electric motor in a start-up mode of operation followed by a normal mode of operation. The motor control circuit and techniques can receive a selection signal provided by a user that can select one of a plurality of sets of parameter values that determine characteristics of drive signals applied to the motor during the start-up mode of operation. The motor control circuit and associated techniques can synchronize operation between the start-up mode of operation and the normal mode of operation.

Abstract: A switching arrangement around a circular vertical Hall (CVH) sensing element can provide a normal mode configuration responsive to magnetic fields at some times, and at least one of a first and a second self-test mode configuration not responsive to a magnetic field but simulating a magnetic field at other times. A corresponding method is also described.

Abstract: A magnetic field sensor with enhanced immunity to external magnetic interference is presented. Included is a magnetic field signal generator and a demodulator. The magnetic field signal generator produces a magnetic field signal having a modulated signal portion in a first frequency band based on a sensed modulated AC bias magnetic field. The modulated AC bias magnetic field is produced by movement of ferromagnetic target relative to a bias coil when an AC signal is applied to the bias coil. When the magnetic field signal also includes an unwanted signal portion in a second frequency band based on external magnetic interference, demodulation performed by the demodulator results in the modulated signal portion being shifted from the first frequency band to a third frequency band and the unwanted signal portion being shifted to the first frequency band. The bias coil may be provided as part of the magnetic field sensor.

Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In some embodiments, AMR sensors having barber pole structures disposed below corresponding AMR sensing elements are provided. AMR sensors having segmented AMR sensing elements are also described. Fabrication techniques that can be used to fabricate such sensors are also described. Fabrication techniques are also described that can reduce the risk of contamination during AMR sensor fabrication.