Abstract: A magnetic field sensor with a plurality of magnetic field sensing elements is provided herein. The magnetic field sensor includes a circular vertical Hall (CVH) sensing element comprising a plurality of vertical Hall elements arranged over a common implant and diffusion region in a substrate, wherein the plurality of vertical Hall elements is configured to generate a plurality of magnetic field signals, each magnetic field signal responsive to a magnetic field.
Abstract: Described embodiments provide an electronic circuit for controlling a motor. The electronic circuit includes a magnetic field sensing circuit responsive to magnetic field sensing elements disposed to sense rotation of the motor. The magnetic field sensing elements generate magnetic field signals, each having a state indicative of at least one of the rotational position and a rotation speed of the motor. A position and speed sensing circuit generates a signal representative of the rotational position of the motor and tracks state changes of the magnetic field signals. A gate driver circuit generates motor drive signals that drive the motor based upon the sensed rotational position. The position and speed sensing circuit generates a qualified control signal based upon a determined valid state change of the magnetic field signals. The gate driver circuit generates the motor drive signals based, at least in part, upon the qualified control signal.
Abstract: An integrated circuit device includes a package and at least two leads exposed external to the package to permit electrical connections to the package. A first die situated in the package has a first substrate and at least a first terminal electrically coupled to a first one of the leads. A second die situated in the package has a second substrate and at least a second terminal electrically coupled to a second one of the lead. An adhesive material holding the first and second die in place forms a voltage-triggered conduction path between the first and second die electrically that isolates the second die from the first die under a first condition and provides an ESD current path between the first one of the leads and the second one of the leads under a second condition.
Type:
Application
Filed:
February 25, 2016
Publication date:
August 31, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
William Wilkinson, Washington Lamar, Maxim Klebanov
Abstract: A double pinned magnetoresistance element has a temporary ferromagnetic layer, two PtMn antiferromagnetic pinning layers, and two associated synthetic antiferromagnetic (SAF) pinned layer structures, the temporary ferromagnetic layer operable to improve annealing of the two PtMn antiferromagnetic pinning layers and the two associated SAFs to two different magnetic directions that are a relative ninety degrees apart.
Abstract: A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element comprising a plurality of vertical Hall elements, each vertical Hall element comprised of a respective group of vertical Hall element contacts selected from among a plurality of vertical Hall element contacts. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage is coupled to receive the signals representative of the plurality of quadrature modulated signals, and operable to perform a sliding window integration using the signals representative of the plurality of quadrature modulated signals and compute an estimated angle of the external magnetic field using the signals representative of the plurality of quadrature modulated signals.
Type:
Grant
Filed:
February 1, 2016
Date of Patent:
August 22, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Octavio H. Alpago, Ezequiel Alves, Hernán D. Romero
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.
Type:
Grant
Filed:
October 3, 2014
Date of Patent:
August 22, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Craig S. Petrie, Bryan Cadugan, David Toebes, Michael C. Doogue, William P. Taylor
Abstract: A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element having a plurality of vertical Hall elements. A CVH output stage is included comprising one or more of drive circuits to drive the plurality of vertical Hall elements and produce an analog signal representing a strength of an external magnetic field as detected by the plurality of vertical Hall elements. An analog-to-digital converter is coupled to receive the analog signal and produce a digital signal. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage receives signals representative of the plurality of quadrature modulated signals and computes an estimated angle of the external magnetic field.
Type:
Grant
Filed:
February 1, 2016
Date of Patent:
August 22, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Octavio H. Alpago, Ezequiel Alves, Hernán D. Romero
Abstract: A magnetic field sensor for detecting motion of an object includes magnetic field sensing elements to generate at least two phase-separated magnetic field signals and a processor including a vector angle generator to generate vector angle values as a function of the magnetic field signals and a vector angle comparator to generate a comparator output signal indicative of a difference between a plurality of vector angle values. An output signal generator responsive to the comparator output signal is configured to generate a sensor output signal indicative of a one or more conditions of motion of the object including: an absence of normal rotation, a direction change, and a vibration. In some embodiments, the vector angle comparator may generate a comparator output signal indicative of a comparison of a vector angle value and one or more threshold values. In this case, the output signal generator may be configured to generate a sensor output signal indicative of a speed of motion and/or a position of the object.
Type:
Grant
Filed:
October 31, 2014
Date of Patent:
August 22, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Christian Feucht, Andreas P. Friedrich, Andrea Foletto
Abstract: A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.
Type:
Application
Filed:
February 12, 2016
Publication date:
August 17, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Simon Tima, Yannick Vuillermet, Andreas P. Friedrich, Thomas Kerdraon
Abstract: In one aspect, a magnetic field sensor includes first and second magnetic field sensing elements having respective first and second maximum response axes. The first and second maximum response axes point along respective first and second different coordinate axes. In response to a magnetic field, the first and second magnetic field sensing elements are operable to generate first and second magnetic field signals. The magnetic field sensor includes an electronic circuit coupled to receive the first and the second magnetic field signals. The electronic circuit is configured to determine a magnitude of a vector sum of the first and the second magnetic field signals and provide one or more signals in response to the magnitude of the vector sum determined.
Type:
Grant
Filed:
August 19, 2015
Date of Patent:
August 15, 2017
Assignee:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Joseph James Judkins, III, Ryan Jon Metivier, Gerardo A. Monreal, Bruno Luis Uberti
Abstract: Systems and techniques detecting a reverse current are disclosed. An apparatus comprises a switching circuit coupled to a load and a reference node. The switching circuit may be capable of conducting a reverse current from the reference node to the load when a voltage at the load is lower than a voltage at the reference node. A voltage source has a first terminal coupled to the load, a second terminal configured to follow a voltage at the load, and produces a voltage proportional to a voltage drop across the switching circuit. A comparator circuit is coupled to compare a voltage at the second terminal of the voltage source to the voltage at the reference node and configured to indicate when the reverse current has a magnitude greater than a predetermined threshold.
Type:
Grant
Filed:
April 29, 2014
Date of Patent:
August 15, 2017
Assignee:
Allegro Microsystems, LLC
Inventors:
James McIntosh, Robert D. Christie, Douglas Bryce, Walter Morrison Stewart Wilson
Abstract: In one aspect, a vertical Hall effect sensor includes a semiconductor wafer having a first conductivity type and a plurality of semiconductive electrodes disposed on the semiconductor wafer. The plurality of semiconductive electrodes have the first conductivity type and include a source electrode, a first sensing electrode and a second sensing electrode, arranged such that the source electrode is between the first sensing electrode and the sensing electrode and a first drain electrode and a second drain electrode, arranged such that the first sensing electrode, second sensing electrode, and source electrode are between the first drain electrode and the second drain electrode. The vertical Hall effect sensor also includes a plurality of semiconductor fingers disposed on the semiconductor wafer and interdigitated with the plurality of semiconductive electrodes, the semiconductor fingers having a second conductivity type.
Abstract: A driver circuit is provided for driving a load, such as a multi-phase motor. The driver circuit includes a gate driver for providing a control signal to switching elements coupled to the driver circuit. A first switching element is coupled between a high supply voltage and a switching node of the load, and a second switching element is coupled between the switching node and a low supply voltage. To detect zero crossings of a current through the load, a zero crossing detector includes a first counter coupled to the switching node and a second counter coupled to the control signal. The first counter and second counter count in a predetermined direction based on a detected voltage of the switching node and based on a detected voltage of the control signal, respectively. The zero crossing detector generates an output signal based upon the difference between the first and the second counter.
Type:
Application
Filed:
February 5, 2016
Publication date:
August 10, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Gianluca Allegrini, Thomas Ross, James McIntosh, Robert Douglas Christie
Abstract: A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element comprising a plurality of vertical Hall elements, each vertical Hall element comprised of a respective group of vertical Hall element contacts selected from among a plurality of vertical Hall element contacts. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage is coupled to receive the signals representative of the plurality of quadrature modulated signals, and operable to perform a sliding window integration using the signals representative of the plurality of quadrature modulated signals and compute an estimated angle of the external magnetic field using the signals representative of the plurality of quadrature modulated signals.
Type:
Application
Filed:
February 1, 2016
Publication date:
August 3, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Octavio H. Alpago, Ezequiel Alves, Hernán D. Romero
Abstract: A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element having a plurality of vertical Hall elements. A CVH output stage is included comprising one or more of drive circuits to drive the plurality of vertical Hall elements and produce an analog signal representing a strength of an external magnetic field as detected by the plurality of vertical Hall elements. An analog-to-digital converter is coupled to receive the analog signal and produce a digital signal. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage receives signals representative of the plurality of quadrature modulated signals and computes an estimated angle of the external magnetic field.
Type:
Application
Filed:
February 1, 2016
Publication date:
August 3, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Octavio H. Alpago, Ezequiel Alves, Hernán D. Romero
Abstract: The present disclosure is directed to methods and systems for providing information about a target based on pulse widths. The information can be provided in a formatted output signal which uses a pulse width protocol to code information by varying amplitudes and widths of successive pulses in an output signal pulse train portion. The method includes detecting a first feature of the target and in response to detecting the first feature, generating an output signal pulse train portion comprising two or more pulses with at least two of the pulses having different amplitudes and each of the two or more pulses having a width corresponding to a logic value. The widths of the two or more pulses in the output signal pulse train portion can be measured in response to the detected first feature reaching a first amplitude threshold, whereby the widths can correspond to different logic values.
Type:
Application
Filed:
January 29, 2016
Publication date:
August 3, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Seth Prentice, Andrea Foletto, Marcus Hagn
Abstract: A magnetic field sensor includes a circular vertical Hall (CVH) sensing element to produce a signal representing an external magnetic field as detected by the CVH sensing element, a sigma-delta analog-to-digital converter to generate a converted signal, modulators to produce quadrature modulated signals from the converted signal, and a processor to produce an estimated angle of the external magnetic field using the quadrature modulated signals. An arctangent function may be used to calculate the estimated angle. A sliding window integration scheme may be used over one or more CVH cycles.
Type:
Application
Filed:
February 1, 2016
Publication date:
August 3, 2017
Applicant:
Allegro Microsystems, LLC
Inventors:
Octavio H. Alpago, Ezequiel Alves, Hernán D. Romero
Abstract: Electronic circuits used in magnetic field sensors use transistors for passing a current through the transistors and also through a magnetoresistance element.
Type:
Grant
Filed:
October 31, 2014
Date of Patent:
August 1, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Mathew Drouin, Devon Fernandez, Jay M. Towne, Alejandro G. Milesi
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:
August 1, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Andrea Foletto, Jeffrey Eagen, Paul A. David
Abstract: A magnetic field sensor includes a true power on state (TPOS) detector for which a measured threshold value is stored prior to power down and recalled upon power up. A corresponding method is associated with the magnetic field sensor.
Type:
Application
Filed:
March 23, 2017
Publication date:
July 6, 2017
Applicant:
Allegro MicroSystems, LLC
Inventors:
Andrea Foletto, Peter Cisar, Eric Shoemaker