Abstract: A method of performing a self-test associated with a magnetic field sensor includes generating a proximity signal responsive to a proximity of a sensed object with one or more magnetic field sensing elements, and identifying one or more characteristic values associated with the proximity signal while the proximity signal is responding to the proximity signal, The method also includes categorizing the one or more characteristic values into three or more potential categories, including three or more categories, wherein the plurality of potential categories is representative of a plurality of discrete self-test states of the proximity signal that could occur while the proximity signal is responding to the proximity of the sensed object. The method also includes communicating at least one of the plurality of potential categories into which at least one of the one or more characteristic values was categorized. A magnetic field senor implements the above method.
Type:
Grant
Filed:
June 18, 2012
Date of Patent:
December 29, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Daniel S. Dwyer, Christine M. Graham, P. Karl Scheller
Abstract: A motor control system is presented. The motor control system includes a motor controller and a motor driver. The motor controller and motor driver are coupled by an interface which includes a conductor configured to carry both a motor speed control signal from the motor controller to the motor driver and a motor feedback signal from the motor driver to the motor controller. The motor controller provides a motor speed control signal to the motor driver and the motor driver provides a motor feedback signal to the motor controller.
Type:
Application
Filed:
June 17, 2014
Publication date:
December 17, 2015
Applicant:
Allegro Microsystems, LLC
Inventors:
Timothy Reynolds, Dennis Hwang, Walter Kim, Thomas Rowan
Abstract: As integrated circuit as open pin detector includes a current source coupled to the pin, a comparator having a first input coupled to the pin, a second input responsive to a threshold voltage, and an output at which a comparator output signal is provided. A controller is responsive to the comparator output signal to provide an enable signed, to the current source and an open pin signal indicative of an open pin condition at the pin. An open pin condition can be detected by comparing the pin voltage to a first threshold voltage level initiating open pin detection in response to the pin voltage falling below the first threshold voltage level, such as by providing a current to the pin, and indicating an open pin condition if the pin voltage rises to exceed a second threshold voltage level within a predetermined time interval. The pin voltage may be prevented from exceeding a predetermined voltage level during open pin detection.
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:
Application
Filed:
August 19, 2015
Publication date:
December 10, 2015
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Joseph James Judkins, III, Ryan Jon Metivier, Gerardo A. Monreal, Bruno Luis Uberti
Abstract: An integrated circuit includes an output circuit having a first terminal adapted to couple to an external power supply, a second terminal adapted to couple to a reference potential, and a third, control terminal. The first and second terminals of the output circuit provide output terminals of the integrated circuit. The integrated circuit further includes an impedance measurement circuit responsive to the external power supply to generate a control signal for coupling to the control terminal of the output circuit. The control signal controls a current level associated with the output circuit. A corresponding method is also described.
Abstract: A magnet includes a magnetic body having a length and width. The body has a first notch in one side and extending along at least a portion of the length of the body, and a second notch in an opposite side of the body extending along at least a portion of the length of the body. A magnetic field produced by the body has a substantially uniform magnetic flux along at least a portion of the length of the body. A system for detecting a target includes one or more magnetic field sensing elements positioned within the portion of the magnetic field having substantially uniform flux.
Abstract: A magnetic field sensor includes a reference-field-sensing circuit channel that allows a self-test or a self-calibration of the circuitry of the magnetic field sensor. The self-test or the self calibration can have at least two different bandwidths that provide a respective at least two different rates of self-test or self-calibration.
Type:
Grant
Filed:
February 16, 2012
Date of Patent:
December 1, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Juan Manuel Cesaretti, Hernan D. Romero
Abstract: A magnetic field sensor with a plurality of magnetic field sensing elements is presented. The magnetic field sensor includes a sequences switches circuit to sequentially select from among the plurality of magnetic field signals. The magnetic field sensor further includes a memory device to store a plurality of potentiometer control values. Also included is a variable potentiometer to attenuate an offset of each one of the plurality of magnetic field signals by using a respective plurality of offset attenuation factors responsive to one or more of the plurality of potentiometer control values. A corresponding method is also described.
Abstract: A switching regulator control circuit includes a circuit configured to generate a control signal to control conduction of the regulator switch in response to a reference signal that is ramped to control a rate of change of the regulated output of the regulator and the control signal is gated in response to a PWM signal.
Abstract: A magnetic field sensor for sensing an external magnetic field includes at least one magnetic field sensing element for measuring a magnetic field produced by a first magnetic field generating source and a current generator configured to receive one or more drive current signals at an input thereof and to generate a drive current signal having a periodic waveform and an amplitude offset at an output thereof. Also included is a second magnetic field generating source configured to receive the drive current signal at an input thereof and in response thereto, provide a magnetic field to the at least one magnetic field sensing element. Additionally included is a comparator configured to receive a reference voltage as a first input and an output signal from the at least one magnetic field sensing element as a second input, and in response thereto to generate a comparator output signal having a duty cycle.
Abstract: A magnetic field sensor uses an angle sensor to measure and angle of rotation of a target object to which a magnet is attached. The angle sensor in combination with electronics can generate an angle sensor output signal related to a direction of a magnetic field of the magnet. The angle sensor output signal can be compared to thresholds to generate a magnetic field sensor output signal the same as a known true power on state (TPOS) sensor output signal. A corresponding method is also described.
Type:
Grant
Filed:
March 6, 2012
Date of Patent:
November 10, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Eric Shoemaker, Michael C. Doogue, Andreas P. Friedrich, Andrea Foletto
Abstract: A circular vertical Hall (CVH) sensing element and an associated method provide a plurality of output signals from a respective plurality of vertical Hall elements in the CVH sensing element at the same time.
Abstract: A fuse formed as part of an integrated circuit has cavities disposed to the sides of the fuse to provide more reliable operation with less chance of re-connection. A method of providing the fuse is also described.
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: A motion sensor has a state processor to identify states associated with a magnetic field signal provided by a magnetic field sensing element. The state processor includes a state peak logic module configured to generate a signal having signal states that have a reduced amount of state chatter.
Type:
Grant
Filed:
April 9, 2013
Date of Patent:
November 3, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Andrea Foletto, Devon Fernandez, Eric Burdette
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:
Application
Filed:
April 29, 2014
Publication date:
October 29, 2015
Applicant:
Allegro Microsystems, LLC
Inventors:
James McIntosh, Robert D. Christie, Douglas Bryce, Walter Morrison Stewart Wilson
Abstract: A motion sensor has a vibration processor to set a flag in response to a plurality of test results provided by a plurality of tests being indicative of a passing condition. A corresponding method and computer-readable storage medium can be used by the motion sensor.
Type:
Grant
Filed:
April 23, 2014
Date of Patent:
October 27, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Andrea Foletto, Devon Fernandez, Eric Burdette
Abstract: A motor control circuit and associated techniques can drive an electric motor in a start-up mode of operation followed by a normal mode of operation. The motor control circuit and techniques can receive a selection signal provided by a user that can select one of a plurality of sets of parameter values that determine characteristics of drive signals applied to the motor during the start-up mode of operation. The motor control circuit and associated techniques can synchronize operation between the start-up mode of operation and the normal mode of operation.
Abstract: In one aspect, a system includes a master component having a communication node; and a plurality of slave components. Each slave component has a bidirectional node. The slave components are configured to each store data in response to a trigger signal received at the bidirectional node from the communication node.
Type:
Grant
Filed:
February 18, 2014
Date of Patent:
October 27, 2015
Assignee:
Allegro Microsystems, LLC
Inventors:
Bryan Cadugan, Michael C. Doogue, Mark J. Donovan
Abstract: A buck-boost switching regulator has an output voltage boost circuit to provide a boosted output voltage. The boosted voltage is used to generate higher voltage control signals to gates of NMOS switches, resulting in an ability to operate at lower input voltages.
Type:
Application
Filed:
April 10, 2015
Publication date:
October 22, 2015
Applicant:
Allegro MicroSystems, LLC
Inventors:
Richard Garvey, Bassem Alnahas, Vijay Mangtani