Allegro Microsystems, LLC

Devon Fernandez

Andrea Foletto

P Karl Scheller

Eric Burdette

Mathew Drouin

William P Taylor

Ravi Vig

Steven E Snyder

Michael Morris

Jay M Towne

Glenn A Forrest

Eric G Shoemaker

Kristann L Moody

Cory Voisine

Karl Scheller

James E Burgess

Kirsten Doogue

Paul A David

Maxim Klebanov

Alejandro Gabriel Milesi

Washington Lamar

Richard B Cooper

Jeff Eagen

Haeyoung Choi

Andreas P Friedrich

Aaron Cook

Christine M Graham

Dominik Weiland

Benjamin Geiger

Naota Nakayama

Peter Tengstrand

Michael Chen

Jacob Harer

Dana Briere

Systems, methods, and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally, one or more IDDQ and/or built-in-self test (BIST) circuits may be included.

Systems and methods for magnetic field sensors with self-test

According to aspects of the disclosure, an apparatus is disclosed comprising: a controller; an analog-to-digital converter (ADC) coupled to the controller, the ADC including an input terminal for receiving a sensor signal from a transducer; and a diagnostic circuit coupled to the input terminal of the ADC and to the controller, the diagnostic circuit being configured to: generate a diagnostic signal that indicates whether a voltage at the input terminal of the ADC meets a first threshold, and provide the diagnostic signal to the controller, wherein the controller is configured to: receive a data sample from the ADC, detect whether the data sample meets a second threshold, and transition the apparatus into a safe state when: (i) the diagnostic signal indicates that the voltage at the input terminal does not meet the first threshold, and (ii) the data sample meets the second threshold.

Data converter false saturation detector

A sensor includes a detector configured to sense a parameter, at least one test circuit configured to detect a respective fault condition of the sensor and generate a fault signal in response to detecting the fault condition, a checker configured to test the at least one test circuit to determine the operational status of the at least one test circuit, and an output signal generator, coupled to receive the sensed parameter, the fault signal, and the operational status of the at least one test circuit. The output signal generator is configured to generate an output signal of the sensor to communicate the sensed parameter and the operational status of the at least one test circuit.

Diagnostic circuits and methods for sensor test circuits

A magnetic field sensor includes a comparator detector for which a measured threshold value is stored prior to power down and recalled upon power up for use by the comparator detector. A corresponding method is associated with the magnetic field sensor.

Magnetic field sensor and associated method that can store a measured threshold value in a memory device during a time when the magnetic field sensor is powered off

A magnetic field sensor for detecting motion of an object includes one or more magnetic field sensing elements configured to generate a magnetic field signal in response to a magnetic field associated with the object. A motion detector responsive to the magnetic field signal and to a threshold signal is configured to generate a detector output signal having edges occurring in response to a comparison of the magnetic field signal and the threshold signal. A speed detector responsive to the detector output signal generates a speed signal indicative of a speed of motion of the object. A delay processor is responsive to the speed signal and configured to determine a delay for the detector output signal based on the speed of motion of the object.

Methods and apparatus for generating a uniform response in a magnetic field sensor

A magnetic field sensor includes one or more magnetic field sensing elements configured to generate a magnetic field signal responsive to a magnetic field and a detector coupled to receive an interpolated threshold and a signal representative of the magnetic field signal, wherein the detector is configured to compare the interpolated threshold with the signal representative of the magnetic field signal to generate a detector output signal. A memory is configured to store a first threshold value indicative of a threshold value at a first temperature and a second threshold value indicative of a threshold value at a second temperature lower than the first temperature and a threshold module coupled to the memory and configured to generate the interpolated threshold based on the stored first and second threshold values.

Magnetic field sensor having a temperature compensated threshold on power up

Electronic circuits used in magnetic field sensors use transistors for passing a current through the transistors and also through a magnetoresistance element.

Magnetic field sensor and electronic circuit that pass amplifier current through a magnetoresistance element

An electronic circuit includes a driver circuit having an output terminal that can be coupled to a load to drive the load. A control circuit is coupled to the driver circuit for controlling the driver circuit. A transistor is coupled in series between the driver circuit and the output terminal. The transistor has a first terminal coupled to the driver circuit and a second terminal coupled to the output terminal. A biasing circuit is coupled to a gate terminal of the transistor and configured to provide a constant voltage to the gate terminal to bias the transistor to a conducting state to reduce the susceptibility of the electronic circuit to electromagnetic interference. The biasing circuit includes a voltage regulator, a Zener diode, and a capacitor. The Zener diode and capacitor are coupled to the gate terminal and a reference terminal.

Output driver having reduced electromagnetic susceptibility and associated methods

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.

Apparatus and methods for extending sensor integrated circuit operation through a power disturbance

An electronic circuit includes semiconductor substrate having a first doping type and a reference terminal coupled to the semiconductor substrate. A tub area having a second doping type is formed in the semiconductor substrate. A well area having the first doping type is formed within the tub area. A driver circuit comprising a transistor is formed within the well area and has an output terminal. A control circuit is coupled to the driver circuit for controlling the driver circuit. A second transistor is within the well area and coupled in series between the driver circuit and the output terminal, the second transistor having a first terminal coupled to the driver circuit and a second terminal coupled to the output terminal. A biasing circuit is coupled to a gate terminal of the second transistor and configured to bias the transistor to a conducting state.

Described embodiments provide circuits, systems and methods for detecting and communicating fault conditions. In an embodiment, an integrated circuit includes a fault detector to detect a fault condition of the integrated circuit and a controller to generate output data of the integrated circuit. An output generator generates an output signal of the integrated circuit. The output signal is generated at a first set of output levels based upon the output data when the fault detector does not detect the fault condition, and the output signal is generated at a second set of output levels based upon the output data when the fault detector detects the fault condition.

Diagnostic fault communication

A magnetic field sensor for detecting motion of an object includes threshold generation circuitry and processing. Magnetic field sensing elements are configured to generate a magnetic field signal in response to a magnetic field associated with the object. A motion detector responsive to the magnetic field signal and to a threshold signal is configured to generate a detector output signal having edges occurring in response to a comparison of the magnetic field signal and the threshold signal. A speed detector responsive to the detector output signal generates a speed signal indicative of a speed of motion of the object. A threshold generator responsive to the speed signal generates the threshold signal having a level that varies in response to the speed signal.

Methods and apparatus for generating a threshold signal in a magnetic field sensor

Systems, methods and apparatuses for magnetic field sensors with self-test include a detection circuit to detect speed and direction of a target. One or more circuits to test accuracy of the detected speed and direction may be included. One or more circuits to test accuracy of an oscillator may also be included. One or more circuits to test the accuracy of an analog-to-digital converter may also be included. Additionally one or more IDDQ and/or built-in-self test (BEST) circuits may be included.

A magnetic field sensor uses upper and lower thresholds. The upper and lower thresholds are limited such that they have a minimum separation distance between equivalent voltage levels of the upper and lower thresholds.

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Londonderry, NH, United States of America

Devon Fernandez