公开(公告)号：US10481219B2

公开(公告)日：2019-11-19

申请号：US15897708

申请日：2018-02-15

Applicant: Allegro MicroSystems, LLC

Inventor： Hernán D. Romero ,  Octavio H. Alpago

IPC: G01R33/07 ,  H03F3/45 ,  H03F1/26 ,  H01L43/04 ,  H03F3/387 ,  H03M1/00

Abstract: 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.

公开(公告)号：US10288698B2

公开(公告)日：2019-05-14

申请号：US15180199

申请日：2016-06-13

Applicant: Allegro MicroSystems, LLC

Inventor： Hernán D. Romero

IPC: G01R33/00 ,  G01P21/02 ,  G01R33/06 ,  G01R35/00

Abstract: A method of calibrating a magnetic field sensor includes setting a first input signal at a first input node of a processor of the magnetic field sensor to a constant value. While the magnetic field sensor experiences a magnetic field, a first transition at an output node of the processor is measured. A second input signal at a second input node of the processor is set to the constant value. While the magnetic field sensor experiences the magnetic field, a second transition of at the output node of the processor is measured. An orthogonality error value is calculated based on a deviation of the first transition and the second transition. The first and/or second input signal is adjusted by modifying the first and/or second input signal by a function of the calculated orthogonality error value to compensate for the orthogonality error.

公开(公告)号：US20190079143A1

公开(公告)日：2019-03-14

申请号：US15700603

申请日：2017-09-11

Applicant: Allegro MicroSystems, LLC

Inventor： Hernán D. Romero ,  Octavio H. Alpago

IPC: G01R33/00 ,  H03F3/38 ,  H03G1/04 ,  H03H17/02

CPC classification number: G01R33/0041 ,  G01D3/036 ,  G01R33/0029 ,  H03F3/38 ,  H03G1/04 ,  H03H17/0219 ,  H03H17/025 ,  H03M3/458

Abstract: 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.

公开(公告)号：US20170219664A1

公开(公告)日：2017-08-03

申请号：US15012131

申请日：2016-02-01

Applicant: Allegro Microsystems, LLC

Inventor： Octavio H. Alpago ,  Ezequiel Alves ,  Hernán D. Romero

IPC: G01R33/07

CPC classification number: G01R33/077 ,  G01D5/145 ,  G01D5/2448 ,  H02K29/08

Abstract: A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element comprising a plurality of vertical Hall elements, each vertical Hall element comprised of a respective group of vertical Hall element contacts selected from among a plurality of vertical Hall element contacts. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage is coupled to receive the signals representative of the plurality of quadrature modulated signals, and operable to perform a sliding window integration using the signals representative of the plurality of quadrature modulated signals and compute an estimated angle of the external magnetic field using the signals representative of the plurality of quadrature modulated signals.