Abstract: An electronic circuit can be disposed upon a semiconductor substrate. An epitaxial layer can be disposed over the semiconductor substrate. The electronic circuit can include a Hall effect element, at least a portion of the Hall effect element disposed in the epitaxial layer. The electronic circuit can further include a current generator configured to generate a drive current that passes through the Hall effect element. The current generator can include a resistor disposed in the epitaxial layer and having characteristics such that a resistance of the resistor can vary with a stress of the semiconductor substrate, resulting in changes of the drive current, to compensate for variations in the sensitivity of the Hall effect element with the stress of the substrate.
Abstract: A magnetic field sensor includes a plurality of magnetic field sensing elements, wherein the plurality of magnetic field sensing elements is configured to generate a plurality of magnetic field signals, each magnetic field sisal responsive to a magnetic field. The magnetic field sensor additionally includes a sequence switches circuit coupled to the plurality of magnetic field sensing elements. The sequence switches circuit is configured to sequentially select from among the plurality of magnetic field signals to generate a sequenced output signal representative of sequentially selected ones of the plurality of magnetic field signals. The magnetic field sensor also includes a variable potentiometer coupled to the sequence switches circuit. The magnetic field sensor additionally includes a gain circuit coupled to receive a signal representative of the offset attenuated sequenced output signal. A corresponding method is also provided.
Abstract: Methods and apparatus for a sensor having non-ratiometric fault trip level setting. In embodiments, a sensor has a sensing element with a fixed gain. A signal processing module receives the fault trip level setting and maintains the fault trip level setting constant during changes in the supply voltage.
Type:
Application
Filed:
October 21, 2015
Publication date:
April 27, 2017
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Alexander Latham, Stephen Marshall, Aaron Cook
Abstract: A sensor integrated circuit includes an energy storage device having a first terminal coupled to a functional circuit and a blocking circuit coupled between a power supply pin and the first terminal of the energy storage device. The blocking circuit permits the energy storage device to store energy from an external power supply coupled to the power pin. The first terminal of the energy storage device is inaccessible from outside of the sensor IC. Additional features of the sensor IC can include a high regulator, a low regulator, and a low power circuit.
Type:
Application
Filed:
September 19, 2016
Publication date:
April 27, 2017
Applicant:
Allegro MicroSystems, LLC
Inventors:
Eric G. Shoemaker, P. Karl Scheller, Devon Fernandez
Abstract: A network slave device includes a transceiver for communicating over a communication bus in accordance with a point-to-point network protocol. The network slave device may have an address to identify the network slave device on the network. It may also have a communication circuit configured to process a series of commands received by the transceiver and respond to a command if a position of the command in the series of commands corresponds to the address of the network slave device. A master device communicating on the network may send the series of command in accordance with the point-to-point network protocol. In an embodiment, the point-to-point protocol is the SENT protocol.
Type:
Grant
Filed:
March 12, 2015
Date of Patent:
April 25, 2017
Assignee:
Allegro Microsystems, LLC
Inventors:
Ricardo Scheinkerman, Nevenka Kozomora, Michael C. Doogue, Richard Vreeland
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:
December 30, 2016
Publication date:
April 20, 2017
Applicant:
Allegro MicroSystems, LLC
Inventors:
Michael C. Doogue, William P. Taylor, Vijay Mangtani
Abstract: 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: Apparatuses for detecting the strength of magnetic fields may include a first magnetic field detection circuit that produces a first signal indicating a strength of a magnetic field, and a second magnetic field detection circuit that can be turned on and off, and produces a second signal indicating the strength of the magnetic field. A control circuit may be configured to determine whether the first signal indicates a change greater than a predetermined amount in the strength of the magnetic field. If the change is greater than the predetermined amount, the control circuit may turn on the second magnetic field detection circuit. The control circuit may turn off the second magnetic field detection circuit to conserve power if the strength of the magnetic field is relatively stable. Methods for detecting the strength of the magnetic field are also disclosed.
Abstract: An electronic circuit has a current generator circuit that generates a two-state output current signal for which a transition between states is altered.
Abstract: A switching regulator control circuit comprises a first control circuit to control conduction of the switch according to a first mode of operation and having a regulation point and a second control circuit to control conduction of the switch according to a second mode of operation in response to a reference signal that is calibrated to have a predetermined relationship with respect to the regulation point of the first control circuit. In some embodiments, the reference signal is calibrated to be a predetermined amount greater than the regulation point of the first control circuit and may be calibrated during the first mode of operation or in response to a regulator start or restart event.
Abstract: In one aspect, a temperature detection circuit includes a first circuit configured to provide a first signal and a comparator circuit configured to provide a warning signal in response to the first signal if a temperature reaches a temperature value. The first signal enables determination of a parameter of a magnetic sensor.
Abstract: Methods and apparatus to provide a magnetic field sensor device including a magnetic sensor element, a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die, and conductive leadfingers having respective portions electrically connected to the wafer bumps. In embodiments, the device includes a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow.
Type:
Grant
Filed:
February 22, 2016
Date of Patent:
April 11, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Shaun D. Milano, Michael C. Doogue, William P. Taylor
Abstract: A controller for a Buck-Boost converter includes a feedback control circuit responsive to the converter output and configured to generate a control signal for the Buck switch and a feed forward control circuit responsive to the input voltage and configured to generate a control signal for the Boost switch. The feed forward circuit is decoupled from the converter output and may be programmable to select a predetermined output voltage.
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:
Grant
Filed:
August 29, 2013
Date of Patent:
April 4, 2017
Assignee:
Allegro Microsystems, LLC
Inventors:
Pranav Raval, Bassem Alnahas, Nai-Chi Lee
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:
Grant
Filed:
April 10, 2015
Date of Patent:
April 4, 2017
Assignee:
Allegro MicroSystems, LLC
Inventors:
Richard Garvey, Bassem Alnahas, Vijay Mangtani
Abstract: A magnetic field sensor and an associated method use one or more magnetoresistance elements driven with an AC mixing current and experiencing an AC mixing magnetic field to generate a DC voltage signal or a DC voltage signal component related to a slope of a transfer curve of the one or more magnetoresistance elements.
Type:
Application
Filed:
September 30, 2015
Publication date:
March 30, 2017
Applicant:
ALLEGRO MICROSYSTEMS, LLC
Inventors:
Gerardo A. Monreal, Andreas P. Friedrich, Claude Fermon, Myriam Pannetier-Lecoeur
Abstract: Magnetic field sensor arrangements and methods provide a magnetic field sensor positioned proximate to a magnet with an axis of sensitivity aligned relative to the magnet in orientations that provide a good sensitivity and a mechanical difference from other arrangements.
Type:
Grant
Filed:
December 21, 2012
Date of Patent:
March 28, 2017
Assignee:
Allegro Microsystems, LLC
Inventors:
Andreas P. Friedrich, Nicolas Yoakim, Andrea Foletto
Abstract: In an embodiment, a magnetic field sensor comprises a substrate and a first magnetoresistive element supported by the substrate. The magnetic field sensor also includes a second magnetoresistive element supported by the substrate and coupled in series with the first magnetoresistive element to form a voltage node between the first and second magnetoresistive elements, and at which an output voltage is provided that changes in response to an external magnetic field. The magnetic field sensor also includes a magnetic source that produces a local magnetic field having a strength sufficient to bias the first magnetoresistive element to a resistive value that is substantially resistant to changing in response to the external magnetic field. In embodiments, additional magnetoresistive elements are included to form an H-bridge circuit.
Abstract: A vertical Hall Effect element includes a low voltage P-well region disposed at a position between pickups of a vertical Hall Effect element to result in an improved sensitivity of the vertical Hall Effect element. A method results in the vertical Hall Effect element having the improved sensitivity.