Patents Assigned to Allegro Microsystems, LLC
  • MAGNETIC FIELD SENSOR HAVING ALIGNMENT ERROR CORRECTION
    Publication number: 20170356966
    Abstract: A method of calibrating a magnetic field sensor includes setting a first input signal at a first input node of a processor of the magnetic field sensor to a constant value. While the magnetic field sensor experiences a magnetic field, a first transition at an output node of the processor is measured. A second input signal at a second input node of the processor is set to the constant value. While the magnetic field sensor experiences the magnetic field, a second transition of at the output node of the processor is measured. An orthogonality error value is calculated based on a deviation of the first transition and the second transition. The first and/or second input signal is adjusted by modifying the first and/or second input signal by a function of the calculated orthogonality error value to compensate for the orthogonality error.
    Type: Application
    Filed: June 13, 2016
    Publication date: December 14, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventor: Hernán D. Romero
  • ARRANGEMENTS FOR MAGNETIC FIELD SENSORS THAT ACT AS MOVEMENT DETECTORS
    Publication number: 20170356761
    Abstract: Magnetic field sensors can sense speed of movement and direction of movement of a ferromagnetic object. The magnetic field sensors employ both planar Hall effect elements and vertical Hall effect elements to generate two-state signals in two different signal paths with relative phases that are ninety degrees apart, the ninety degrees having sufficient margin to aid in detection of the direction of motion. Other magnetic field sensors use at least four vertical Hall effect elements to identify a speed of rotation and a direction of rotation of a moving ferromagnetic object.
    Type: Application
    Filed: June 8, 2016
    Publication date: December 14, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventors: Ravi Vig, Paul A. David, Eric G. Shoemaker
  • MAGNETIC FIELD SENSOR FOR SENSING A PROXIMITY OF AN OBJECT
    Publication number: 20170356759
    Abstract: A back-biased magnetic field sensor uses one or more magnetic field sensing elements upon a substrate, each outside of a substrate region in which magnetic field lines are near perpendicular to the substrate and outside of which magnetic field lines are not to the substrate. The back-biased magnetic field sensor can sense an approaching and/or a retreating ferromagnetic object.
    Type: Application
    Filed: June 8, 2016
    Publication date: December 14, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventors: Paul A. David, Ravi Vig
  • Digital demodulator for pulse-width modulated (PWM) signals in a motor controller
    Patent number: 9843285
    Abstract: Described embodiments provide circuits, systems and methods for digitally demodulating a pulse-width modulated (PWM) signal in a motor control system. An electronic circuit of the motor control system includes an input to receive a speed demand signal that is a PWM signal having a duty cycle associated with a requested speed of a motor. A PWM demodulator demodulates the PWM signal and generates an N-bit digital speed value representative of the requested speed of the motor, where N is a positive integer. A motor driver generates, based at least in part upon the N-bit digital speed value, one or more control signals to operate the motor.
    Type: Grant
    Filed: July 22, 2016
    Date of Patent: December 12, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventor: Yisong Lu
  • Magnetic field sensor having calibration circuitry and techniques
    Patent number: 9841485
    Abstract: A magnetic field sensor includes at least one magnetic field sensing element configured to generate a measured magnetic field signal responsive to an external magnetic field and to generate a reference magnetic field signal responsive to a reference magnetic field and a calibration circuit configured to divide the measured magnetic field signal by the reference magnetic field signal to generate a calibrated magnetic field signal. The calibrated signal has reduced susceptibility to stress influences.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: December 12, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: Craig S. Petrie, Bryan Cadugan
  • SENSORLESS BRUSHLESS DIRECT CURRENT (BLDC) MOTOR POSITION CONTROL
    Publication number: 20170346420
    Abstract: Described embodiments provide circuits, systems and methods for controlling operation of brushless direct current motors that include a plurality of windings. A gate driver provides control signals to switching elements that control a voltage applied to each of the windings of the motor. A zero crossing detector detects zero crossings of a voltage applied to the windings and transitions a zero crossing signal between a first logic level and a second logic level based on the detected zero crossings. A position estimator estimates an angular position of the motor, and counts in a first direction based on the first logic level of the zero crossing signal, and in a second direction based on the second logic level of the zero crossing signal. An observer determines a value of the counter after an elapsed time, and generates an angular position signal based upon the value of the counter.
    Type: Application
    Filed: May 25, 2016
    Publication date: November 30, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventors: Thomas Ross, Gianluca Allegrini, Yi Li
  • GAIN EQUALIZATION FOR MULTIPLE AXIS MAGNETIC FIELD SENSING
    Publication number: 20170336481
    Abstract: A magnetic field sensor for sensing external magnetic fields on multiple axes comprises a coil structure and a gain equalization circuit. The coil structure generates reference fields on magnetic field sensing elements in each axis. The gain equalization circuit measures and compares reference fields to generate gain-equalized output signals responsive to the external magnetic fields.
    Type: Application
    Filed: May 23, 2016
    Publication date: November 23, 2017
    Applicant: Allegro Microsystems, LLC
    Inventors: Alexander Latham, Craig S. Petrie
  • Magnetic field sensor for sensing a movement of a target object
    Patent number: 9823090
    Abstract: A magnetic field sensor operates as a motion detector for sensing a movement of a ferromagnetic target object having features. The magnetic field sensor has a plurality of magnetoresistance elements to generate, in a first channel, a feature signal indicative of a proximity of a feature of a ferromagnetic target object and, in a second channel, an edge signal indicative of a proximity of an edge of a feature of a ferromagnetic target object.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: November 21, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: Andrea Foletto, Yannick Vuillermet, Andreas P. Friedrich
  • Magnetic field sensor providing a movement detector
    Patent number: 9823092
    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.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: November 21, 2017
    Assignee: Allegro Microsystems, LLC
    Inventors: Paul A. David, William P. Taylor
  • Compensating for voltage changes in driver circuits
    Patent number: 9825528
    Abstract: In one aspect, an integrated circuit (IC) is configured to receive an input signal and includes a boost duty cycle control circuit configured to provide duty cycle control to a power conversion stage configured to drive a load. The power conversion stage is configured to receive an input voltage. The IC also includes a current control circuit configured to control current of a first current source coupled to the first load and an inverter configured to provide an output signal comprising a negative of the input voltage, the output of the inverter configured to be coupled to the boost duty cycle control circuit.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: November 21, 2017
    Assignee: Allegro Microsystems, LLC
    Inventors: Nai-Chi Lee, Pranav Raval
  • Magnetic Field Sensor Providing A Movement Detector
    Publication number: 20170328739
    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.
    Type: Application
    Filed: July 25, 2017
    Publication date: November 16, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventors: Paul A. David, William P. Taylor
  • Magnetic field sensors and associated methods for removing undesirable spectral components
    Patent number: 9817083
    Abstract: Magnetic field sensors and associated techniques use a Hall effect element in a chopping arrangement in combination with a feedback path configured to reduce undesirable spectral components generated by the chopping.
    Type: Grant
    Filed: July 5, 2012
    Date of Patent: November 14, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventor: Hernan D. Romero
  • Methods and apparatus for magnetic sensor having integrated coil
    Patent number: 9817078
    Abstract: Methods and apparatus for a magnetic field sensor including a die, a coil proximate the die to generate a magnetic field, and a magnetic field sensing element having to detect changes in the magnetic field generated by the coil in response to a ferromagnetic target.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: November 14, 2017
    Assignee: ALLEGRO MICROSYSTEMS LLC
    Inventors: Gary T. Pepka, William P. Taylor
  • Motor Control Using Phase Current and Phase Voltage
    Publication number: 20170324364
    Abstract: Methods and apparatus to control a three-phase BLDC motor using phase current and phase voltage at zero current detection and a driving current derived from a bus current, for example.
    Type: Application
    Filed: May 9, 2016
    Publication date: November 9, 2017
    Applicant: ALLEGRO MICROSYSTEMS, LLC.
    Inventor: Yisong Lu
  • Arrangements for magnetic field sensors that act as tooth detectors
    Patent number: 9810519
    Abstract: A variety of magnetic field sensor arrangements provide so-called “tooth detectors” using a simple low-cost magnet.
    Type: Grant
    Filed: July 19, 2013
    Date of Patent: November 7, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: William P. Taylor, P. Karl Scheller, Paul David
  • Magnetic field sensor integrated circuit with integral ferromagnetic material
    Patent number: 9812588
    Abstract: A magnetic field sensor includes a lead frame, a semiconductor die having a first surface in which a magnetic field sensing element is disposed and a second surface attached to the lead frame, and a non-conductive mold material enclosing the die and at least a portion of the lead frame. The sensor may include a ferromagnetic mold material secured to a portion of the non-conductive mold material. Features include a multi-sloped taper to an inner surface of a non-contiguous central region of the ferromagnetic mold material, a separately formed element disposed in the non-contiguous central region, one or more slots in the lead frame, a molded ferromagnetic suppression device spaced from the non-conductive mold material and enclosing a portion of a lead, a passive device spaced from the non-conductive mold material and coupled to a plurality of leads, and a ferromagnetic bead coupled to a lead.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: November 7, 2017
    Assignee: Allegro Microsystems, LLC
    Inventors: Ravi Vig, William P. Taylor, Paul David, P. Karl Scheller, Andreas P. Friedrich
  • Spin valve magnetoresistance element with improved response to magnetic fields
    Patent number: 9812637
    Abstract: A spin valve magnetoresistance element has an even number of free layer structures for which half has an antiferromagnetic coupling and the other half has a ferromagnetic coupling with respect to associated pinned layers. The different couplings are the result of an even number different spacer layers having respective different thicknesses.
    Type: Grant
    Filed: May 26, 2016
    Date of Patent: November 7, 2017
    Assignees: Allegro MicroSystems, LLC, Commissariat A L'Energie Atomique Et Aux Energies Alternatives
    Inventors: Claude Fermon, Paolo Campiglio, Bryan Cadugan
  • Arrangements For Magnetic Field Sensors That Act As Tooth Detectors
    Publication number: 20170314907
    Abstract: A variety of magnetic field sensor arrangements provide so-called “tooth detectors” using a simple low-cost magnet.
    Type: Application
    Filed: July 20, 2017
    Publication date: November 2, 2017
    Applicant: Allegro MicroSystems, LLC
    Inventors: William P. Taylor, P. Karl Scheller, Paul A. David
  • Dual-path analog to digital converter
    Patent number: 9804249
    Abstract: Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: October 31, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: Craig S. Petrie, Soo-Chang Choe
  • Magnetic field sensor with shared path amplifier and analog-to-digital-converter
    Patent number: 9804222
    Abstract: Methods and apparatus for processing a signal comprise at least one circuit configured to generate a measured signal during a measured time period and a reference signal during a reference time period. Also included is at least one dual- or multi-path analog-to-digital converter comprising at least a first processing circuit configured to process the measured signal, at least a second processing circuit configured to process the reference signal, and a third processing circuit configured to process both the measured signal and the reference signal.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: October 31, 2017
    Assignee: Allegro MicroSystems, LLC
    Inventors: Craig S. Petrie, Bryan Cadugan