Patents Assigned to Allegro Microsystems Inc.
  • Hall effect element having a hall plate with a perimeter having indented regions
    Patent number: 7936029
    Abstract: A Hall effect element includes a Hall plate with an outer perimeter. The outer perimeter includes four corner regions, each tangential to two sides of a square outer boundary associated with the Hall plate, and each extending along two sides of the square outer boundary by a corner extent. The outer perimeter also includes four indented regions. Each one of the four indented regions deviates inward toward a center of the Hall plate. The Hall plate further includes a square core region centered with and smaller than the square outer boundary. A portion of each one of the four indented regions is tangential to a respective side of the square core region. Each side of the square core region has a length greater than twice the corner extent and less than a length of each side of the square outer boundary.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: May 3, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventor: Yigong Wang
  • Self-calibration algorithms in a small motor driver IC with an integrated position sensor
    Patent number: 7936144
    Abstract: A motion control device for controlling a motor is presented. The motion control device is operable to scale or adjust an input relative to an input range that is based on calibration values and to use that scaled input to produce a drive signal to drive the motor. The motion control device performs a self-calibration to produce the calibration values. The self-calibration involves measuring home position and full travel position values for the motor.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: May 3, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Ravi Vig, Paul David, Shaun D. Milano, Michael C. Doogue, David J. Haas
  • Folding current sensor
    Patent number: 7936164
    Abstract: The invention provides a current sensor that may be folded over a conductor without the need to sever the conductor or thread the conductor through the current sensor. In one embodiment, the current sensor includes an outer body having a first folding portion and a second folding portion coupled to the first folding portion. The current sensor also includes a soft ferromagnetic body disposed within the outer body comprising a first core element and a second core element. The first and second core elements form a lumen when the first and second folding portions are folded. The lumen is configured to receive a conductor. The current sensor also includes a magnetic field detector to sense a current in the conductor. The magnetic field detector is disposed at least partially between the first and second core elements when the first and second folding portions are folded.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: May 3, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, William P. Taylor, Richard Dickinson
  • Magnetic field sensor with automatic sensitivity adjustment
    Patent number: 7923996
    Abstract: Magnetic field sensors have a magnetic field sensing element and also a feedback circuit to provide a gain-adjustment signal to affect a sensitivity associated with the magnetic field sensing element. In some arrangements, the feedback circuit can include piezoresistors to sense a strain of a substrate over which the magnetic field sensor is disposed. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed strain. In other arrangements, the feedback circuit can generate pulsed magnetic fields proximate to the magnetic field sensing element in order to directly measure the sensitivity of the magnetic field sensing element. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed sensitivity.
    Type: Grant
    Filed: February 26, 2008
    Date of Patent: April 12, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, Gerardo Monreal, William P. Taylor
  • Magnetic Field Sensor with Automatic Sensitivity Adjustment
    Publication number: 20110074405
    Abstract: Magnetic field sensors have a magnetic field sensing element and also a feedback circuit to provide a gain-adjustment signal to affect a sensitivity associated with the magnetic field sensing element. In some arrangements, the feedback circuit can include piezoresistors to sense a strain of a substrate over which the magnetic field sensor is disposed. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed strain. In other arrangements, the feedback circuit can generate pulsed magnetic fields proximate to the magnetic field sensing element in order to directly measure the sensitivity of the magnetic field sensing element. With these arrangements, the feedback circuit can generate the gain-adjustment signal in accordance with the sensed sensitivity.
    Type: Application
    Filed: December 3, 2010
    Publication date: March 31, 2011
    Applicant: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, Gerardo Monreal, William P. Taylor
  • Sensor having an analog processing module to generate a linear position output
    Patent number: 7911203
    Abstract: A sensor having a signal generation module including a first magnetic sensor, an analog signal processing module, and a signal inversion module for inverting a first waveform and a second waveform, wherein the signal inversion module outputs the first and second waveforms in a first region spanning a first range of angular position of the magnet and outputs the first and second inverted waveforms in a second region spanning a second range of angular position of the magnet.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: March 22, 2011
    Assignee: Allegro Microsystems, Inc.
    Inventors: Monica J. Thomas, Michael C. Doogue, Hooman Bustani
  • Circuits and Methods for Generating a Diagnostic Mode of Operation in a Magnetic Field Sensor
    Publication number: 20110018533
    Abstract: A magnetic field sensor includes a diagnostic circuit that allows a self-test of most of or all of, the circuitry of the magnetic field sensor, including a self-test of a magnetic field sensing element used within the magnetic field sensor. The magnetic field sensor can generate a diagnostic magnetic field to which the magnetic field sensor is responsive.
    Type: Application
    Filed: July 21, 2010
    Publication date: January 27, 2011
    Applicant: Allegro Microsystems, Inc.
    Inventors: Juan Manuel Cesaretti, Gerardo Monreal, William P. Taylor, Michael C. Doogue
  • METHODS FOR MULTI-STAGE MOLDING OF INTEGRATED CIRCUIT PACKAGE
    Publication number: 20100330708
    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: Application
    Filed: September 9, 2010
    Publication date: December 30, 2010
    Applicant: Allegro Microsystems, Inc.
    Inventors: Raymond W. Engel, Nirmal Sharma, William P. Taylor
  • Method and apparatus for thermal management of a radio frequency system
    Patent number: 7859835
    Abstract: A thermal management system includes an air duct assembly comprising a supply air duct having an air inlet opening, a return air duct having an air exit opening and a plurality of distribution air ducts configured to be in fluid communication with the air inlet opening of the supply air duct and with the air exit opening of the return air duct. A fan is disposed within the air duct assembly to direct air from the air inlet opening of the supply air duct through the supply air duct and out the air exit opening of the return air duct. The fan and supply duct are disposed to direct air over a first surface of a heat sink. A second opposing surface of the heat sink is disposed over and configured to be in thermal contact with a plurality of active circuits disposed on a first surface of a radio frequency (RF) multi-layer printing wiring board (PWB).
    Type: Grant
    Filed: June 10, 2009
    Date of Patent: December 28, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Angelo M. Puzella, Joseph A. Licciardello, Stephen J. Pereira, Joseph R. Ellsworth
  • Matching of GMR sensors in a bridge
    Patent number: 7859255
    Abstract: A magnetoresistive (MR) sensing device includes MR elements electrically connected to form a bridge circuit and one or more non-functional (or “dummy”) MR elements for improved matching of the bridge circuit MR elements.
    Type: Grant
    Filed: July 21, 2010
    Date of Patent: December 28, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, William P. Taylor
  • Methods and apparatus for DC-DC converter having independent outputs
    Patent number: 7851940
    Abstract: A DC-DC converter includes independent first and second outputs to drive respective first and second loads from a common boost module. In one embodiment, a first linear regulator controls a first controlling device for the first output and a second linear regulator controls a second controlling device for the second output. The load requiring the higher voltage controls the boost module.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: December 14, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Mir Mahin, John Humenick, Shashank Wekhande
  • Circuit combining a switching regulator and an overvoltage detection circuit
    Patent number: 7834603
    Abstract: An electronic circuit combines a synchronous switching regulator circuit with an overvoltage detection circuit. The overvoltage detection circuit is configured to generate an overvoltage signal capable of an overvoltage state indicative of a power supply voltage being above a predetermined threshold voltage. The switching regulator circuit is coupled to receive the overvoltage signal. The switching regulator is also configured, in response to the overvoltage signal being in the overvoltage state, to generate a first control signal resulting in at least one of two series coupled transistors being in an off condition.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: November 16, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Vijay Mangtani, Weiyun Chen, Ravi Vig
  • MATCHING OF GMR SENSORS IN A BRIDGE
    Publication number: 20100283458
    Abstract: A magnetoresistive (MR) sensing device includes MR elements electrically connected to form a bridge circuit and one or more non-functional (or “dummy”) MR elements for improved matching of the bridge circuit MR elements.
    Type: Application
    Filed: July 21, 2010
    Publication date: November 11, 2010
    Applicant: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, William P. Taylor
  • Methods and apparatus for multi-stage molding of integrated circuit package
    Patent number: 7816772
    Abstract: Methods and apparatus 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: March 29, 2007
    Date of Patent: October 19, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Raymond W. Engel, Nirmal Sharma, William P. Taylor
  • Arrangements for a current sensing circuit and integrated current sensor
    Patent number: 7816905
    Abstract: An electronic circuit for sensing a current includes a circuit board having first and second major opposing surfaces and a current conductor for carrying the current. The current conductor includes a circuit trace disposed upon the circuit board. The electronic circuit also includes an integrated circuit disposed upon and electrically coupled to the circuit board at a position so as to straddle the current conductor.
    Type: Grant
    Filed: June 2, 2008
    Date of Patent: October 19, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, Richard Dickinson, William P. Taylor
  • Arrangements For An Integrated Sensor
    Publication number: 20100237450
    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.
    Type: Application
    Filed: June 2, 2010
    Publication date: September 23, 2010
    Applicant: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, William P. Taylor, Vijay Mangtani
  • Integrated circuit having built-in self-test features
    Patent number: 7800389
    Abstract: An integrated circuit includes a sensor for providing a sensor output signal and a diagnostic circuit coupled to the sensor for providing a self-diagnostic signal. The self-diagnostic signal comprises the sensor output signal during a first time duration and an inverted sensor output signal during a second different time duration.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: September 21, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Andreas P. Friedrich, Andrea Foletto, P. Karl Scheller, Paul David
  • Matching of GMR sensors in a bridge
    Patent number: 7795862
    Abstract: A magnetoresistive (MR) sensing device includes MR elements electrically connected to form a bridge circuit and one or more non-functional (or “dummy”) MR elements for improved matching of the bridge circuit MR elements.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: September 14, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Michael C. Doogue, William P. Taylor
  • Capacitor charging methods and apparatus
    Patent number: 7787262
    Abstract: A capacitor charging circuit is provided with a primary side output voltage sensing circuit including an RC network having an RC time constant with a predetermined relationship to the RC time constant of the output capacitor. Once the capacitor voltage reaches a fully charged level, the charging mode is terminated. The output voltage is continuously detected by measuring the voltage across the primary side RC network that decays at a predetermined rate with respect to the output capacitor and the charging mode is commenced once the RC voltage falls to a predetermined level. According to a further aspect of the invention, a switch control circuit in a flyback converter controls the switch off time in response to detection of a change in the slope polarity of the voltage at a terminal of the switch.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: August 31, 2010
    Assignee: Allegro Microsystems, Inc.
    Inventors: Vijay Mangtani, Nai-Chi Lee, Tseng-Nan Tsai, John Humenick
  • Circuits and Methods for Generating a Self-Test of a Magnetic Field Sensor
    Publication number: 20100211347
    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.
    Type: Application
    Filed: February 16, 2010
    Publication date: August 19, 2010
    Applicant: Allegro Microsystems, Inc.
    Inventors: Andreas P. Friedrich, Andrea Foletto, Michael C. Doogue, William P. Taylor, Ravi Vig, P. Karl Scheller