Patents Assigned to Allegro Microsystems Inc.
  • Patent number: 8169161
    Abstract: Electronic circuits provide an error signal to control a regulated output voltage signal generated by a controllable DC-DC converter for driving one or more series connected strings of light emitting diodes.
    Type: Grant
    Filed: November 10, 2008
    Date of Patent: May 1, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: Gregory Szczeszynski, Bassem AlNahas, Vijay Mangtani
  • Patent number: 8164324
    Abstract: A rotation sensor includes a detecting portion, a rotational state determining portion and a pulse generating portion. The detecting portion detects a rotation of a rotational member and outputs a detection signal. The rotational state determining portion determines a rotational state of the rotational member on the basis of the detection signal in a predetermined period. The pulse generating portion generates and outputs a first pulse and a second pulse, of which waveforms differ from each other, in response to a rotational direction of the rotational member after the predetermined period. The pulse generating portion further generates and outputs a third pulse regardless of the rotational state of the rotational member in the predetermined period.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: April 24, 2012
    Assignees: Aisin Seiki Kabushiki Kaisha, Allegro Microsystems, Inc.
    Inventors: Takashi Hara, Hidenobu Muramatsu, Glenn A. Forrest, Hitoshi Yabusaki, Naota Nakayama
  • Publication number: 20120086444
    Abstract: A magnetic field sensor includes a compensation loop coupled in series with normal circuit couplings in order to reduce a transient signal that would otherwise be generated when the magnetic field sensor experiences a high rate of change of magnetic field. In some embodiments, the magnetic field sensor is a current sensor responsive to a magnetic field generated by a current-carrying conductor.
    Type: Application
    Filed: October 8, 2010
    Publication date: April 12, 2012
    Applicant: ALLEGRO MICROSYSTEMS, INC
    Inventors: Weihua Chen, Michael G. Ward
  • Publication number: 20120086090
    Abstract: Methods and apparatus provide a sensor including a component coupled to the leadframe such that the component is an integrated part of the IC package.
    Type: Application
    Filed: December 14, 2011
    Publication date: April 12, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: Nirmal Sharma, Virgil Ararao, Leonardo T. Magpantay, Raymond W. Engel, William P. Taylor, Kirsten Doogue, Jay Gagnon
  • Publication number: 20120086442
    Abstract: A magnetic field sensor and a method associated with the magnetic field sensor provide gain correction coefficients and/or offset correction coefficients stored in the magnetic field sensor in digital form. The gain correction coefficients and/or offset correction coefficients can be used to generate analog control signals to control a sensitivity and/or an offset of an analog signal path through the magnetic field sensor.
    Type: Application
    Filed: October 12, 2010
    Publication date: April 12, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: David J. Haas, Ravi Vig
  • Publication number: 20120086414
    Abstract: A set top box used in a satellite TV system includes a diode coupled in a particular way to better protect an adjustable linear regulator used in the set top box from transient voltages as may result from lighting or the like.
    Type: Application
    Filed: October 12, 2010
    Publication date: April 12, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventor: Eric J. Reicher
  • Patent number: 8143169
    Abstract: Methods for providing an integrated circuit using a multi-stage molding process to protect wirebonds. In one embodiment, a method includes attaching a die to a leadframe having a lead finger, attaching a wirebond between the die and the leadfinger, applying a first mold material over at least a portion of the wirebond and the die and the leadfinger to form an assembly, waiting for the first mold material to at least partially cure, and applying a second mold material over the assembly.
    Type: Grant
    Filed: September 9, 2010
    Date of Patent: March 27, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: Raymond W. Engel, Nirmal Sharma, William P. Taylor
  • Patent number: 8138708
    Abstract: A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: March 20, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael G. Ward, David J. Haas
  • Patent number: 8125216
    Abstract: A sensor minimizes effects of sensor element misalignment with respect to a magnet. In one embodiment, a sensor comprises a magnet, first, second, third, and fourth sensor elements positioned in relation to the magnet, and a signal processing module to process output signals from the first, second, third, and fourth sensor elements and generate first and second differential signals for minimizing effects of positional misalignment of the first, second, third, and fourth sensor elements with respect to the magnet by maximizing a quadrature relationship of the first and second differential signals.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: February 28, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: Monica J. Thomas, David J. Haas
  • Patent number: 8122159
    Abstract: In one aspect, a system includes electrical components arranged in a daisy chain that include a first electrical component disposed at a first end of the daisy chain and a second electrical component disposed at an opposite end of the daisy chain than the first end. Each of the first and second electrical components includes an input port, an output port and a common port. The input port of the first electrical component is coupled to one of a supply voltage port or ground and the common ports of the first and second electrical components are coupled to the other one of the supply voltage or the ground. An address of the second electrical component is determined before addresses of the other of the electrical components are determined, and the addresses of the electrical components determine a position of an electrical component with respect to the other of the electrical components in the daisy chain.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: February 21, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventor: Gerardo Monreal
  • Publication number: 20120025817
    Abstract: A magnetic field sensor includes a Hall element configured to generate a Hall element output signal in response to a magnetic field, the Hall element output signal comprising a magnetic field signal component and an offset signal component. The magnetic field sensor also includes a Hall element modulation circuit coupled to receive the Hall element output signal and configured to generate a modulation circuit output signal. The Hall element modulation circuit is modulated with a modulation signal having a changing modulation frequency that changes between a minimum frequency and a maximum frequency.
    Type: Application
    Filed: July 28, 2010
    Publication date: February 2, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: Hernan D. Romero, Gerardo Monreal
  • Publication number: 20120013327
    Abstract: A magnetic field sensor includes a linear magnetic field sensor to produce a voltage proportional to a sensed magnetic field and an interface having only two terminals for external connections. The two terminals of the interface include a power supply terminal and a ground terminal. The interface includes a voltage-controlled current generating device that is connected between the two terminals and is controlled by the voltage to provide a current signal that is proportional to the sensed magnetic field.
    Type: Application
    Filed: September 22, 2011
    Publication date: January 19, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, Jonathan Lamarre, Monica J. Thomas
  • Publication number: 20120013333
    Abstract: Magnetic field sensors and associated methods of manufacturing the magnetic field sensors include molded structures to encapsulate a magnetic field sensing element and an associated die attach pad of a lead frame and to also encapsulate or form a magnet or a flux concentrator.
    Type: Application
    Filed: September 23, 2011
    Publication date: January 19, 2012
    Applicant: ALLEGRO MICROSYSTEMS, INC.
    Inventors: Virgil Ararao, Nirmal Sharma, Raymond W. Engel, Jay Gagnon, John Sauber, William P. Taylor, Elsa Kam-Lum
  • Publication number: 20120014682
    Abstract: A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.
    Type: Application
    Filed: September 22, 2011
    Publication date: January 19, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: Paul David, Shaun D. Milano
  • Publication number: 20120008929
    Abstract: A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.
    Type: Application
    Filed: September 22, 2011
    Publication date: January 12, 2012
    Applicant: Allegro Microsystems, Inc.
    Inventors: Paul David, Shaun D. Milano
  • Patent number: 8093844
    Abstract: A motor control circuit that features a smart, two-phase braking operation is presented. The motor control circuit includes a motor drive circuit to apply a brake current to a coil of an external motor for active braking of the motor. The motor control circuit further includes a braking control circuit, coupled to the motor drive circuit and responsive to an externally generated control signal, to control the active braking by the motor drive circuit so that the active braking occurs in two phases. The two phases include a first phase that includes a first portion of the active braking and a second phase that includes back electromotive force (BEMF) voltage sensing and a second portion of the active braking.
    Type: Grant
    Filed: March 12, 2009
    Date of Patent: January 10, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: Alejandro G. Milesi, Bruno L. Uberti
  • Patent number: 8093670
    Abstract: Methods and apparatus for providing an integrated circuit including a substrate having a magnetic field sensor, first and second conductive layers generally parallel to the substrate, and a dielectric layer disposed between the first and second conductive layers such that the first and second conductive layers and the dielectric layer form a capacitor, wherein a slot is formed in at least one of the first and second conductive layers proximate the magnetic field sensor for reducing eddy currents in the first and second conductive layers.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: January 10, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventor: William P. Taylor
  • Patent number: 8089270
    Abstract: Apparatus for detecting a passing magnetic article includes a peak detector providing a detector output signal that changes state when the magnetic field signal differs from a magnetic field tracking signal by more than a threshold offset amount. The threshold offset amount is dynamically variable in response to detection of a speed of rotation of the magnetic article and a peak-to-peak signal level of the magnetic field signal.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: January 3, 2012
    Assignee: Allegro Microsystems, Inc.
    Inventors: P. Karl Scheller, Ravi Vig
  • Patent number: 8084969
    Abstract: A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.
    Type: Grant
    Filed: October 1, 2007
    Date of Patent: December 27, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Paul David, Shaun D. Milano
  • Patent number: 8080994
    Abstract: An integrated current sensor includes a current conductor, a magnetic field transducer, and an electromagnetic shield. The magnetic field transducer includes a sensor die. The electromagnetic shield is disposed proximate to the sensor die. The electromagnetic shield has at least one feature selected to reduce an eddy current in the electromagnetic shield.
    Type: Grant
    Filed: October 30, 2008
    Date of Patent: December 20, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: William P. Taylor, Michael C. Doogue, John Cummings, Vijay Mangtani