Allegro Microsystems, LLC

Octavio H Alpago

Hernán D Romero

Nicolas Rigoni

Nicolás Rafael Biberidis

Ezequiel Alves

Ezequiel Rubinsztain

Franco Noel Martin Pirchio

Gerardo A Monreal

Juan Manuel Cesaretti

Sundar Chetlur

Alejandro Gabriel Milesi

Harianto Wong

Bruno Luis Uberti

James McClay

Leandro Tozzi

Vyankatesh Gupta

Lautaro Casella

Muhammed Sarwar

Ignacio Lesser

Ahmed Hassan Fahmy

A magnetic field sensor includes a magnetic field sensing element to generate a magnetic field signal indicative of a sensed magnetic field, a modulator to modulate the magnetic field signal at a chopping frequency, a front end amplifier coupled to receive the magnetic field signal and generate an amplified signal, and a demodulator configured to demodulate the amplified signal at the chopping frequency. The sensor further includes a low pass filter to process the amplified signal and generate a low pass filtered signal and a Schmitt trigger circuit. The Schmitt trigger circuit includes a comparator having a first input coupled to receive the low pass filtered signal, a second input coupled to receive a reference signal, and an output at which a comparator output signal is provided. The comparator is configured to perform a plurality of comparisons within a chopping time period that is the inverse of the chopping frequency.

Reduced area magnetic field sensor topology

A method comprising: obtaining at least three sampled values m, each of the sampled values m including a respective first component that is obtained based on a first signal and a respective second component that is obtained based on a second signal and solving a system of equations to yield at least one of (i) an offset adjustment vector k, (ii) a sensitivity mismatch coefficient &#x3b3;, and (iii) a non-orthogonality coefficient s, the system of equations being arranged to model each of the sampled values m as a function of: a respective one of a plurality of number arrays, a magnetic field, and the at least one of (i) the offset adjustment vector k, (ii) the sensitivity mismatch coefficient &#x3b3;, and (iii) the non-orthogonality coefficient s.

Adaptive angle sensor

An angle sensor comprising: a plurality of magnetic field sensing elements configured to detect a magnetic field and generate a respective plurality of analog magnetic field signals; a plurality of analog frontend circuits each analog frontend circuit associated with a respective magnetic field sensing element; and a digital feedback circuit configured to generate digital magnetic field signals from the plurality of analog magnetic field signals and generate digital error correction values, wherein the plurality of analog frontend circuits are configured to obtain the digital error correction values from the digital feedback circuit, generate analog correction values from the digital error correction values, and apply the analog correction values to the plurality of analog magnetic field signals to generate a plurality of corrected analog magnetic field signals.

Analog angle sensor with digital feedback loop

A magnetic field angle sensor includes a coil configured to generate a magnetic field that induces an eddy current in a rotatable target, a first magnetic field sensing structure positioned proximate to the coil and configured to detect a reflected magnetic field generated by the eddy current induced in the target, a second magnetic field sensing structure positioned proximate to the coil and configured to detect the reflected magnetic field generated by the eddy current induced in the target, wherein the first and second magnetic field sensing structures are configured to detect quadrature components of the reflected magnetic field, and a processing module configured to process the reflected magnetic field detected by the first and second magnetic field sensing structures for determining an angular position of the target.

Angle sensor using eddy currents

In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic-field signal at a first frequency; a first channel; a second channel; a subtractor circuit configured to subtract a second channel output signal from a first channel output signal to form a subtraction signal; an adder circuit configured to combine the first channel output signal and the second channel output signal to form a summation signal; processing circuitry configured to receive the summation signal and to provide a magnetic-field sensor output signal indicating a position of the target; feedback circuitry configured to receive the subtraction signal and to provide a first feedback signal to the processing circuitry, and a second feedback signal; and a secondary coil circuitry configured to receive the second feedback signal and to generate, based on the second feedback signal, a second magnetic-field signal to reduce the first magnetic-field signal received.

Reducing stray magnetic field effects using a magnetic field feedback

An angle sensor can have a plurality of magnetic field sensing elements configured to detect a magnetic field and generate a respective plurality of magnetic field signals. In response to these magnetic field signals, a processor generates an uncorrected angle signal that is indicative of an angle of the magnetic field. An error corrector generates an error value using one or more of the previous samples of the uncorrected angle signal, and a summation element applies the error value to a current sample of the uncorrected angle signal to generate a corrected angle signal. The error corrector can generate the error value by applying a correction factor to a previous sample of the uncorrected angle signal, or by applying a correction factor to a predicted current sample of the uncorrected angle signal.

Angle sensor with offline error correction

A method comprising: performing a first read from an address in a data storage module by using a first read voltage; storing, in a first register, data that is retrieved from the data storage module as a result of the first read; performing a second read from the address by using a second read voltage; storing, in a second register, data that is retrieved from the data storage module as a result of the second read; detecting whether a weak bit condition is present at the address based on the data that is stored in the first register and the data that is stored in the second register; and correcting the weak bit condition, when the weak bit condition is present at the address.

Method and apparatus for eliminating bit disturbance errors in non-volatile memory devices

A method is disclosed for use in an electronic device having a non-volatile storage device and a volatile storage device, the method comprising: retrieving a first encoded data packet from a first address in the non-volatile storage device; decoding the first encoded data packet to obtain a first data item and a first error code corresponding to the first data item, the first encoded data packet being decoded by using a first coding key that is associated with the first address; detecting whether the first data item is corrupt based on the first error code and an error correction function, storing the first data item at a first address in the volatile storage device when the first data item is not corrupt, and transitioning the electronic device into a safe state when the first data item is corrupt.

Non-volatile memory data and address encoding for safety coverage

Methods and apparatus for a TMR-based sensor having a first magnetic field sensing element comprising a bridge having first, second, third, and fourth legs. Legs of the bridge comprise TMR elements with pillars connected to one or more switch matrixes to adjust total resistances of the bridge legs. Equalizing the resistance of the bridge legs can enhance sensor performance.

TMR magnetic sensor

An integrated circuit sensor can have a test program generator that is configured to receive a portion of a scan vector, where the scan vector includes a test mode signal and a scan enable signal. The test program generator is configured to retrieve a launch-off-capture test sequence from the scan vector and use the launch-off-capture test sequence and the test mode signal to generate a launch-off-capture test signal. A test signal generator is configured to generate a launch-off-shift test signal using the launch-off-capture test signal and the scan enable signal. A built-in self-test circuit is configured to test the integrated circuit sensor using the launch-off-shift test signal.

Fault test circuit using launch-off-shift scan

A magnetic field sensor includes a first magnetic field sensing element first generating a first signal having a first axis of maximum sensitivity, a second magnetic field sensing element for generating a second signal and having a second axis of maximum sensitivity, one or more detectors for receiving an output of the first magnetic field sensing element or the second magnetic field sensing element, and a processor that receives an output of the one or more detectors and uses the output of the one or more detectors to calculate a first constant Kand a second constant Kand then uses Kand Kto compensate for an orthogonality error between the first axis of maximum sensitivity and second axis of maximum sensitivity. The detectors include peak detectors and/or zero-crossing detectors that compare the output of the first input signal or the second input signal with a threshold or zero.

Non-orthogonality compensation of a magnetic field sensor

A method for multi-level memory safety for a sensor integrated circuit can include loading a blocking bit into a volatile memory from a non-volatile memory and providing the blocking bit to a gating circuit from the volatile memory. Further, the method may include the gating circuit determining whether to provide a default value to a functional logic based upon the provided blocking bit.

Multi-level memory safety of a sensor integrated circuit

A magnetic field sensor includes a circular vertical Hall (CVH) sensing element to produce a signal representing an external magnetic field as detected by the CVH sensing element, a sigma-delta analog-to-digital converter to generate a converted signal, modulators to produce quadrature modulated signals from the converted signal, and a processor to produce an estimated angle of the external magnetic field using the quadrature modulated signals. An arctangent function may be used to calculate the estimated angle. A sliding window integration scheme may be used over one or more CVH cycles.

Circular vertical hall (CVH) sensing element with signal processing and arctangent function

A sensor circuit may include one or more feedback loops to process and attenuate ripple and/or a test signal. The sensor circuit may comprise at least one magnetic field sensing element to generate a magnetic field signal representing a magnetic field to be measured, a test signal generator circuit configured to generate a test signal and combine the test signal with the magnetic field signal to generate a combined signal, and a signal path for processing the combined signal. The signal path may comprise an amplifier circuit to amplify the combined signal, an analog-to-digital converter (ADC) to convert the combined signal to a digital combined signal, and a feedback circuitry coupled to receive the digital combined signal and extract the test signal. A test comparator circuit compares the extracted test signal to a reference signal.

Magnetic field sensor with feedback loop for test signal processing

A sensor circuit is provided with a chopper-stabilized amplifier circuit configured to receive a signal from at least one magnetic sensing element, a sigma-delta modulator (SDM) configured to receive a signal from the chopper-stabilized amplifier circuit, and a feedback circuit configured to reduce ripple in a signal generated by the chopper-stabilized amplifier circuit. The feedback circuit includes a demodulator to demodulate a signal from the SDM in a digital domain by inverting a bit stream of the signal from the SDM according to a frequency chopping rate, a digital integrator configured to integrate an output signal of the demodulator to form an integrated signal, and a digital-to-analog converter (DAC) configured to convert the integrated signal to an analog signal and provide the analog signal to the chopper-stabilized amplifier circuit.

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Buenos Aires, Argentina

Octavio H Alpago