Allegro Microsystems, LLC

Eric Burdette

Devon Fernandez

Andrea Foletto

William P Taylor

Paul A David

Eric G Shoemaker

Michael C Doogue

Ravi Vig

Andreas P Friedrich

Christine M Graham

Marie-Adelaide Lo

P Karl Scheller

Glenn A Forrest

Steven E Snyder

James M Bailey

Daniel S Dwyer

Jeff Eagen

Seth Prentice

Michael Chen

Jacob Harer

A magnetic field sensor includes a lead frame, a passive component, semiconductor die supporting a magnetic field sensing element and attached to the lead frame, a non-conductive mold material enclosing the die and at least a portion of the lead frame, and a ferromagnetic mold material secured to a portion of the non-conductive mold material. The lead frame has a recessed region and the passive component is positioned in the recessed region. The ferromagnetic mold material may comprise a soft ferromagnetic material to form a concentrator or a hard ferromagnetic material to form a bias magnet.

Magnetic field sensor integrated circuit with integral ferromagnetic material

An apparatus and a method provide an output signal indicative of a speed of rotation and/or a direction of movement of a ferromagnetic object having ferromagnetic features and capable of moving. A variety of signal formats of the output signal are described, each of which have pulses at a rate faster than the ferromagnetic features pass by the magnetic field sensor.

Magnetic field sensors and output signal formats for a magnetic field sensor

Methods and apparatus for detecting a magnetic field include a magnetic source configured to provide a magnetic field to induce an eddy current in a non-ferromagnetic target, and a magnetic field sensing element configured to detect the magnetic field as a result of the eddy current. The magnetic field provided by the magnetic source can be a static (i.e. DC) field or a changing (i.e. non-DC) field.

Methods and apparatus for magnetic sensor having an integrated coil or magnet to detect a non-ferromagnetic target

A magnetic field sensor includes a lead frame, a semiconductor die supporting a magnetic field sensing element, a non-conductive mold material enclosing the die and a portion of the lead frame, a ferromagnetic mold material secured to the non-conductive mold material and a securing mechanism to securely engage the mold materials. The ferromagnetic mold material may comprise a soft ferromagnetic material to form a concentrator or a hard ferromagnetic material to form a bias magnet. The ferromagnetic mold material may be tapered and includes a non-contiguous central region, as may be an aperture or may contain the non-conductive mold material or an overmold material. Further embodiments include die up, lead on chip, and flip-chip arrangements, wafer level techniques to form the concentrator or bias magnet, integrated components, such as capacitors, on the lead frame, and a bias magnet with one or more channels to facilitate overmolding.

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.

Circuits and methods for limiting a smallest separation of thresholds in a magnetic field sensor

An electronic circuit has a current generator circuit that generates a two-state output current signal for which a transition between states is altered.

Electronic circuit for driving an output current signal and method of driving the output current signal from the electronic circuit to achieve an altered transition of the output current signal

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.

Motion sensor, method, and computer-readable storage medium providing a motion sensor generating a signal having signal states with a reduced amount of state chatter

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.

Motion sensor, method, and computer-readable storage medium providing a motion sensor with a vibration processor to set a state of a flag in response to selected ones of a plurality of test results being indicative of a passing conditions

A circuit to detect a movement of an object includes a magnetic field sensing element for generating a magnetic field signal proportional to a magnetic field associated with the object and a motion detector to generate a motion signal indicative of the movement of the object. The motion detector includes a peak identifying circuit to provide a peak signal and a peak sample selection module that selects a sample associated with one or more prior cycles of a magnetic field signal to generate a selected peak signal. The motion detector further includes a threshold generator to generate a threshold signal as a function of the selected peak signal and a comparator to compare the threshold signal with the magnetic field signal to generate the motion signal. Peak samples from prior magnetic field signal cycles may be averaged for use to establish the threshold signal. A method associated with the circuit is also described.

Circuits and methods for generating a threshold signal used in a magnetic field sensor based on a peak signal associated with a prior cycle of a magnetic field signal

A motion sensor has an output protocol processor configured to provide a validated output signal after a determined time period, wherein the determined time period is extended if a vibration is detected.

Motion sensor, method, and computer-readable storage medium providing a motion sensor with a validated output signal from the motion sensor

A motion sensor includes an amplitude difference processor coupled to receive a first signal representative of a first one of a plurality of AGC control signals and a second signal representative of a second one of the plurality of AGC control signals. The amplitude difference processor is configured to detect if a value of the first signal is representative of a different gain than a value of the second signal by a predetermined amount. In response to the detection, the AGC processor is configured to change the value of the first one of the plurality of AGC control signals to bring its value closer to the value of the second one of the AGC control signals. A method and computer-readable storage medium can use the motion sensor.

Motion sensor, method, and computer-readable storage medium providing a motion sensor that adjusts gains of two circuit channels to bring the gains close to each other

A motion sensor has a magnetic field sensing element for generating a magnetic field signal and a state processor to identify a plurality of states corresponding to ranges of signal values of the magnetic field signal. The state processor includes a state peak logic module configured to generate states that have a reduced amount of state chatter.

Motion sensor, method, and computer-readable storage medium providing a motion sensor with a magnetic field sensing element for generating a magnetic field signal and a state processor to identify a plurality of states corresponding to ranges of values of the magnetic field signal having a reduced amount of state chatter

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Newmarket, NH, United States of America

Eric Burdette