Abstract: A system and an associated method provide an ability to sense, with a magnetic field sensor, a position of a plurality of gears (and neutral) selected by a gear shift lever of a vehicle. In some embodiments, the system and method use a ferromagnetic target having features, positions of which can be sensed by the magnetic field sensor. In other embodiments, the system and method use a magnet having features and characteristics that can be sensed by the magnetic field sensor.
Type:
Grant
Filed:
May 31, 2012
Date of Patent:
June 2, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Andreas P. Friedrich, Andrea Foletto, Cedric Gillet
Abstract: The linear position of an object is estimated using multiple magnetic field sensors and a magnet. The multiple magnetic field sensors are held in fixed relation to one another and in moving relation with respect to the magnet. Readings of the first and second magnetic field sensors and the fixed distance between the first and second magnetic field sensors may be used to estimate the linear position. In some embodiments, an estimated frequency of an approximately sinusoidal field versus position characteristic is also used as part of the estimation.
Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In at least one embodiment, an AMR sensor is provided that includes barber pole structures having upper and low metal layers that are formed of different materials. The metal material closer to the AMR element is formed of a material that can be etched using an etching process that does not attack the AMR material. In some other embodiments, AMR sensors having segmented AMR sensing elements are described.
Type:
Grant
Filed:
October 1, 2013
Date of Patent:
April 21, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
David G. Erie, Joseph Burkhardt, Steven Kosier
Abstract: An angle sensor to provide sensor-to-magnet misalignment detection and correction capability in rotation angle measurement applications is presented. The angle sensor has magnetic field sensing elements to sense magnetic field associated with a rotating magnet. The angle sensor includes circuitry to generate signals based on the sensing by the sensing elements. The signals provide information that can be combined according to an error function to provide misalignment detection. The angle sensor can be used with or can be incorporated in an angle measurement device that employs a processing unit to produce a rotation angle value. In one embodiment, the processing unit is configured to implement the error function and correct the angle value for detected misalignment. In another embodiment, the error function is performed by a programming device and detected misalignment is corrected through mechanical adjustment of sensor-to-magnet position.
Type:
Grant
Filed:
April 4, 2012
Date of Patent:
April 14, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Andreas P. Friedrich, Andrea Foletto, P. Karl Scheller, William P. Taylor, Michael C. Doogue
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.
Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In at least one embodiment, an AMR sensor is provided that includes barber pole structures having upper and low metal layers that are formed of different materials. The metal material closer to the AMR element is formed of a material that can be etched using an etching process that does not attack the AMR material. In some other embodiments, AMR sensors having segmented AMR sensing elements are described.
Type:
Application
Filed:
October 1, 2013
Publication date:
April 2, 2015
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
David G. Erie, Joseph Burkhardt, Steven Kosier
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: An apparatus and a method provide an output signal indicative of a speed of rotation and a direction of rotation of a ferromagnetic object capable of rotating. A variety of signal formats of the output signal are described.
Type:
Grant
Filed:
December 2, 2013
Date of Patent:
March 31, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Ravi Vig, P. Karl Scheller, Paul A. David
Abstract: Control circuits and techniques are provided for use with DC-DC converters. The circuits and techniques may, in some implementations, be used with LED driver systems. In some embodiments control circuits are provided that rely on multiple different feedback paths to adjust a duty cycle of a DC-DC converter. In some embodiments, control circuits are provided that switch between multiple capacitors to provide as duty cycle control signal for use with a DC-DC converter.
Type:
Grant
Filed:
January 29, 2013
Date of Patent:
March 31, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Pranav Raval, Gregory Szczeszynski, Bassem Alnahas, Nai-Chi Lee
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.
Type:
Application
Filed:
November 21, 2014
Publication date:
March 19, 2015
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Andreas P. Friedrich, Andrea Foletto, Gary T. Pepka
Abstract: An LED driver circuit selects a regulated voltage value for use in driving one or more LEDs based on dimming duty cycle. In some embodiments, the regulated voltage value may be selected in accordance with a function that decreases monotonically with increasing dimming duty cycle. In this manner, LED current accuracy can be achieved at lower dimming duty cycles, while still achieving enhanced operational efficiency at higher dimming duty cycles.
Type:
Application
Filed:
August 29, 2013
Publication date:
March 5, 2015
Applicant:
Allegro Microsystems, LLC
Inventors:
Pranav Raval, Bassem Alnahas, Nai-Chi Lee
Abstract: A circuit to detect a movement of an object provides a threshold selection module or a peak identifier module that uses one or more threshold signals identified prior to a present cycle of magnetic field signal in order to establish a threshold signal used for a present cycle of the magnetic field signal. A method associated with the circuit is also described. The circuit and method can be tailored to store values associated with a least common multiple of a set of possible quantities of detectable features on target objects.
Type:
Application
Filed:
August 6, 2014
Publication date:
March 5, 2015
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Devon Fernandez, Michael Morris, William P. Taylor, P. Karl Scheller
Abstract: In one aspect, an integrated circuit (IC) includes an isolation trench dividing the IC into a first section and a second section, an active electronic device disposed in the first section of the IC and a capacitor disposed in the second section of the IC and electrically isolated from the active electronic device.
Abstract: An electronic circuit for driving an electronic switch includes a first voltage terminal coupled to receive a first voltage from a power supply and a second voltage terminal coupled to receive a second voltage from the power supply. A driver circuit is configured to drive the voltage at a control terminal of the electronic switch to an intermediate voltage level in order to turn on the electronic switch during a high or normal voltage condition. A clamp circuit is configured to clamp the voltage at the control terminal of the electronic switch to the second voltage terminal in order to turn on the electronic switch during a low voltage condition, so that the electronic switch can enhance power provided to a load during the low voltage condition. A low voltage detection circuit detects the low voltage condition and provides a signal to activate the clamp circuit.
Abstract: The linear position of an object is estimated using multiple magnetic field sensors and a magnet. The multiple magnetic field sensors are held in fixed relation to one another and in moving relation with respect to the magnet. Readings of the first and second magnetic field sensors and the fixed distance between the first and second magnetic field sensors may be used to estimate the linear position. In some embodiments, an estimated frequency of an approximately sinusoidal field versus position characteristic is also used as part of the estimation.
Abstract: An integrated circuit includes an output driver circuit having a plurality of output driver devices connected in a parallel arrangement and an output driver controller that is capable of individually controlling the conducting states of the output driver devices. In at least one embodiment, the controller is capable of achieving any of a plurality of different fall times (and/or rise times) in an output signal by appropriately controlling the conducting states of the output devices if a change in the state of the output signal is desired, in some implementations, the controller is capable of achieving different waveshapes during rising and/or failing edges of an output signal.
Abstract: An integrated magnetic field sensor includes a magnetic field sensing element configured to generate a magnetic field sensing element output signal in response to a magnetic field. The integrated magnetic field sensor also includes a threshold control node configured to receive a control signal from outside of the integrated magnetic field sensor, wherein the integrated magnetic field sensor is configured to provide an adjustable threshold signal in response to the control signal. The integrated magnetic field sensor also includes a comparator having a first input node coupled to receive a first signal representative of the magnetic field sensing element output signal, a second input node coupled to receive a second signal representative of the adjustable threshold signal, and an output node at which is generated an output signal responsive to the first and second signals.
Type:
Grant
Filed:
May 6, 2011
Date of Patent:
February 17, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Paul David, Andreas P. Friedrich, Gary T. Pepka, Nevenka Kozomora
Abstract: Systems and methods for sensing position of a magnetic target are disclosed. In embodiments, three magnetic field sensing elements are arranged equidistantly from each other to define a plane and a central axis perpendicular to the plane. The magnetic field sensing elements are configured to generate a respective output signal representing proximity of a magnetic target that is proximate to the central axis and capable of moving relative to the central axis. A processor circuit is coupled to receive output signals from each of the sensors and configured to calculate a position of the magnetic target relative to the plane.
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:
Grant
Filed:
June 14, 2013
Date of Patent:
February 10, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Michael C. Doogue, William P. Taylor, Vijay Mangtani
Abstract: In one aspect, a magnetic field sensor is configured to detect a ferromagnetic object. The magnetic field sensor includes a magnet that includes two North regions and two South regions configured to generate opposing directions of magnetization to form a magnetic flux. The magnetic field sensor also includes a magnetic field sensing element configured to generate an is output signal responsive to changes in the magnetic flux caused by movement of the ferromagnetic object.