Patents by Inventor Andrey Timopheev

Andrey Timopheev has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20250085365
    Abstract: Magnetoresistive element comprising a reference layer having a fixed reference magnetization; a ferromagnetic sense layer having a free sense magnetization having a stable vortex configuration that is orientable relative to the fixed reference magnetization in the presence of an external magnetic field; and a tunnel barrier layer between the reference layer and the sense layer and contacting a first side of the sense layer. The magnetoresistive element further comprises a hard magnetic layer arranged on a second side (212) of the sense layer opposed to the first side, the hard magnetic layer being configured to generate an interfacial magnetic coupling between the hard magnetic layer and the sense layer on the second side, such as to prevent chirality switching of the sense magnetization after the magnetoresistive element has been submitted to a heat treatment and an external magnetic field above vortex expulsion field.
    Type: Application
    Filed: February 22, 2023
    Publication date: March 13, 2025
    Applicant: Allegro MicroSystems, LLC
    Inventors: Salim DOUNIA, Léa CUCHET, Nikita STRELKOV, Clarisse DUCRUET, Andrey TIMOPHEEV, Jeffrey CHILDRESS
  • Patent number: 12228620
    Abstract: Magnetic angular sensor element destined to sense an external magnetic field, including a magnetic tunnel junction containing a ferromagnetic pinned layer having a pinned magnetization, a ferromagnetic sensing layer, and a tunnel magnetoresistance barrier layer; the ferromagnetic sensing layer including a first sensing layer being in direct contact with the barrier layer and having a first sensing magnetization, a second sensing layer having a second sense magnetization, and a metallic spacer between the first sensing layer and the second sensing layer; wherein the metallic spacer is configured to provide an antiferromagnetic coupling between the first sensing magnetization and the second sensing magnetization such that the first sensing magnetization is oriented substantially antiparallel to the second sensing magnetization; the second sensing magnetization being larger than the first sensing magnetization, such that the second sensing magnetization is oriented in accordance with the direction of the externa
    Type: Grant
    Filed: May 10, 2021
    Date of Patent: February 18, 2025
    Assignee: Allegro MicroSystems, LLC
    Inventors: Andrey Timopheev, Jeffrey Childress, Nikita Strelkov
  • Patent number: 12204005
    Abstract: A magnetoresistive element for a magnetic sensor, the magnetoresistive element including a tunnel barrier layer between a reference layer having a fixed reference magnetization and a sense layer having a free sense magnetization, wherein the sense magnetization includes a stable vortex configuration. The magnetoresistive element further includes a reference pinning layer in contact with the reference layer and pining the reference magnetization by exchange-bias at a first blocking temperature. The magnetoresistive element further includes a sense pinning layer in contact with the sense layer and pining the sense magnetization by exchange-bias at a second blocking temperature lower that the first blocking temperature. Additionally, a method for manufacturing the magnetoresistive element.
    Type: Grant
    Filed: October 28, 2021
    Date of Patent: January 21, 2025
    Assignee: Allegro MicroSystems, LLC
    Inventors: Jeffrey Childress, Nikita Strelkov, Andrey Timopheev
  • Publication number: 20250004073
    Abstract: The present disclosure concerns a magnetoresistive element comprising a reference layer having a reference magnetization oriented out-of-plane; a sense layer having a sense magnetization comprising a vortex configuration stable under the presence of an external magnetic field and reversibly movable in a direction out-of-plane relative to the reference magnetization when the external magnetic field varies in a direction out-of-plane; and a tunnel barrier layer between the reference layer and the sense layer. The sense layer has a thickness smaller than 200 nm. The sense layer comprises a ferromagnetic material configured such that the sense magnetization is between 300 and 1400 emu/cm3 and such that the sense layer has a perpendicular magnetic anisotropy field that is greater than 1 kOe (79.6×103 A/m). The present disclosure further concerns a magnetoresistive sensor comprising a plurality of the magnetoresistive element.
    Type: Application
    Filed: December 2, 2022
    Publication date: January 2, 2025
    Applicant: Allegro MicroSystems, LLC
    Inventors: Nikita Strelkov, Andrey Timopheev, Léa Cuchet
  • Patent number: 12174276
    Abstract: A magnetoresistive element for a 2D magnetic sensor, the magnetoresistive element including a tunnel barrier layer included between a reference layer having a reference magnetization and a sense layer having a sense magnetization. The sense layer includes a sense synthetic antiferromagnetic structure including a first sense sublayer in contact with the tunnel barrier layer and separated from a second sense sublayer by a first non-magnetic spacer layer such that the first sense sublayer is antiferromagnetically coupled to the second sense sublayer.
    Type: Grant
    Filed: September 14, 2021
    Date of Patent: December 24, 2024
    Assignee: Allegro MicroSystems, LLC
    Inventors: Andrey Timopheev, Nikita Strelkov, Jeffrey Childress
  • Publication number: 20240395448
    Abstract: Magnetoresistive element comprising a tunnel barrier layer, a ferromagnetic reference layer having a fixed reference magnetization, and a ferromagnetic sense layer having a sense magnetization that can be changed by an external magnetic field (Bext). The reference, tunnel barrier, and sense layers are stacked perpendicular to a layer plane (PL) thereof. At least a portion of the magnetoresistive element comprising the sense layer has a hollow cross-sectional shape in the layer plane (PL), the cross-sectional shape having an outer side with an outer lateral size (Dout) and an inner side defining a width (wd) of the cross-sectional shape. The outer lateral size (Dout) is between 1 ?m and 5 ?m and the width (wd) is between 0.2 ?m and 0.3 ?m. The sense magnetization has a coreless vortex configuration and such that the magnetoresistive element has zero remanence at zero external magnetic field (Bext). The present disclosure further concerns a magnetic switch comprising the magnetoresistive element.
    Type: Application
    Filed: May 10, 2024
    Publication date: November 28, 2024
    Applicant: Allegro MicroSystems, LLC
    Inventors: Nikita Strelkov, Andrey Timopheev, Salim Dounia
  • Publication number: 20240345182
    Abstract: A magnetoresistive element comprising a reference layer, a ferromagnetic sense layer having a free sense magnetization, and a tunnel barrier layer between the reference layer and the sense layer. The sense layer comprises a first sense layer portion in contact with the tunnel barrier layer and a second sense layer portion in contact with the first sense layer portion. The first sense layer portion is configured such that a magnetic coupling between the first and second sense layer portions is between ±10?4 J/m2 and ±10?3 J/m2; and a perpendicular magnetic anisotropy (PMA) originating from the interface between the first sense layer portion and the tunnel barrier layer is between 8×104 A/m and 8×105 A/m, such as to shift positively the TCS of the magnetoresistive element and compensate the negative temperature coefficient of TMR of the magnetoresistive element.
    Type: Application
    Filed: July 8, 2022
    Publication date: October 17, 2024
    Applicant: Allegro MicroSystems, LLC
    Inventors: Andrey Timopheev, Clarisse Ducruet, Jeffrey Childress
  • Patent number: 12102011
    Abstract: A magnetic sensor including a plurality of magnetoresistive elements; each magnetoresistive element including a ferromagnetic layer having a magnetization that is orientable at or above a threshold temperature; the magnetic sensor further includes a plasmonic structure destined to be irradiated by electromagnetic radiation and including a spatially periodic plasmonic array of metallic structures. The period of the plasmonic array and the lateral dimension of the metallic structures are adjusted to obtain plasmon resonance of the plasmonic structure for a given wavelength of the electromagnetic radiation. The plasmonic array is arranged in the magnetic sensor such as to heat the first ferromagnetic layer at or above the threshold temperature, from the enhanced absorption of the electromagnetic radiation by plasmon resonance. The present disclosure further concerns a system including the sensor and an emitting device configured to emit electromagnetic radiation.
    Type: Grant
    Filed: May 27, 2021
    Date of Patent: September 24, 2024
    Assignee: Allegro MicroSystems, LLC
    Inventors: Andrey Timopheev, Nikita Strelkov, Jeffrey Childress
  • Publication number: 20240210498
    Abstract: A method to calculate performance of a magnetic element including a reference bilayer including a ferromagnetic reference layer having a reference magnetization and an antiferromagnetic layer pining the reference magnetization by exchange-bias, the antiferromagnetic layer including a metallic polycrystalline material having a grain volume distribution; the method comprising: measuring an exchange-bias field (Hex) of the antiferromagnetic layer as a function of temperature; fitting a grain volume distribution function to the measured exchange-bias fields (Hex) to determine parameters characterizing the volume distribution function; calculating a variation in the direction of the reference magnetization as a function of a direction of an exposure magnetic field (H); and calculating the exchange bias field (Hex) for any value of the in-plane exposure magnetic field (H).
    Type: Application
    Filed: April 4, 2022
    Publication date: June 27, 2024
    Applicant: Allegro MicroSystems, LLC
    Inventors: Nikita Strelkov, Andrey Timopheev, Jeffrey Childress
  • Publication number: 20240168108
    Abstract: A magnetoresistive element has a tunnel barrier layer included between a ferromagnetic reference layer having a fixed reference magnetization and a ferromagnetic sense layer having a free sense magnetization. The sense magnetization has a ferromagnetic material composition and a stable vortex configuration in the absence of an applied magnetic field. The ferromagnetic material composition varies across the thickness of the sense layer from a composition with higher magnetization near the tunnel barrier layer to a composition with lower magnetization away from the tunnel barrier layer, such that the sense magnetization and ferromagnetic exchange strength of the sense layer are higher near the tunnel barrier layer than away from the tunnel barrier layer.
    Type: Application
    Filed: March 15, 2022
    Publication date: May 23, 2024
    Applicant: Allegro MicroSystems, LLC
    Inventors: Jeffrey Childress, Andrey Timopheev
  • Patent number: 11946985
    Abstract: An electronic circuit for measuring an angle and an intensity of an external magnetic field, includes: first and second magnetic field sensing units having sensing axes substantially orthogonal to each other; a voltage generator supplying a synchronization signal, a first voltage waveform to the first magnetic field sensing unit and a second voltage waveform to the second magnetic field sensing unit; a signal conditioning unit configured for adding the first and second sensing output signals and outputting a conditioned signal. The first and second voltage waveforms have substantially the same amplitude and frequency and are phase shifted by about 90° with respect to each other. The conditioned signal and the synchronization signal are inputted into a magnetic field angle detection unit configured for measuring a phase shift between the conditioned signal and the synchronization signal and for determining the angle of the external magnetic field from the measured phase shift.
    Type: Grant
    Filed: March 19, 2020
    Date of Patent: April 2, 2024
    Assignee: Allegro MicroSystems, LLC
    Inventors: Andrey Timopheev, Ali Alaoui, Evgeny Burmistrov
  • Patent number: 11906553
    Abstract: Magnetic current sensor, including: a sensor bridge circuit including a first and second half-bridges, each including two series-connected and diagonally opposed tunnel magnetoresistive (TMR) sensor elements, the TMR sensor elements including a reference layer oriented a single predetermined direction and a sense layer having a sense magnetization; a field line configured for passing a field current generating a magnetic field adapted for orienting the sense magnetization of the diagonally opposed TMR sensor elements of the first half-bridge and of the diagonally opposed TMR sensor elements of the second half-bridge in an opposite direction; such that a non-null differential voltage output between the TMR sensor elements of the first half-bridge and the TMR sensor elements of the second half-bridge is measurable when the field current is passed in the field line; the differential voltage output being insensitive to the presence of an external uniform magnetic field.
    Type: Grant
    Filed: June 26, 2020
    Date of Patent: February 20, 2024
    Assignee: CROCUS TECHNOLOGY SA
    Inventor: Andrey Timopheev
  • Publication number: 20240019509
    Abstract: A magnetoresistive element for a magnetic sensor, the magnetoresistive element including a tunnel barrier layer between a reference layer having a fixed reference magnetization and a sense layer having a free sense magnetization, wherein the sense magnetization includes a stable vortex configuration. The magnetoresistive element further includes a reference pinning layer in contact with the reference layer and pining the reference magnetization by exchange-bias at a first blocking temperature. The magnetoresistive element further includes a sense pinning layer in contact with the sense layer and pining the sense magnetization by exchange-bias at a second blocking temperature lower that the first blocking temperature. Additionally, a method for manufacturing the magnetoresistive element.
    Type: Application
    Filed: October 28, 2021
    Publication date: January 18, 2024
    Inventors: Jeffrey Childress, Nikita Strelkov, Andrey Timopheev
  • Patent number: 11860250
    Abstract: Magnetic angular sensor device destined to sense an external magnetic field, the sensor device including a plurality of magnetic sensor elements, each sensor element including a magnetic tunnel junction containing a ferromagnetic reference layer having a reference magnetization that is pinned in a pinning direction, a ferromagnetic sense layer having a sense magnetization that can be oriented in an external magnetic field, and a tunnel barrier spacer layer, between the reference layer and the sense layer; wherein the sense layer of at least a portion of said plurality of sensor elements comprises an in-plane uniaxial sense magnetic anisotropy having an easy axis that is aligned substantially parallel to the pinning direction, such that an angular deviation in the alignment of the direction of the sense magnetization in the external magnetic field is minimized for a range of external magnetic field.
    Type: Grant
    Filed: November 26, 2019
    Date of Patent: January 2, 2024
    Assignee: CROCUS TECHNOLOGY SA
    Inventor: Andrey Timopheev
  • Publication number: 20230296703
    Abstract: A magnetoresistive element for a 2D magnetic sensor, the magnetoresistive element including a tunnel barrier layer included between a reference layer having a reference magnetization and a sense layer having a sense magnetization. The sense layer includes a sense synthetic antiferromagnetic structure including a first sense sublayer in contact with the tunnel barrier layer and separated from a second sense sublayer by a first non-magnetic spacer layer such that the first sense sublayer is antiferromagnetically coupled to the second sense sublayer. The sense layer is configured such that a sense magnetic ratio ?M defined as: ? M = M s F M 2 t F M 2 ? M s F M 1 t F M 1 M s F M 2 t F M 2 + M s F M 1 t F M 1 wherein MSFM1 and MSFM2 are the spontaneous magnetizations of the first and second sense sublayers and tFM1 and tFM2 are the thicknesses of the first and second sense sublayers; and wherein the sense magnetic ratio is between 0.1 and 0.25.
    Type: Application
    Filed: September 14, 2021
    Publication date: September 21, 2023
    Inventors: Andrey Timopheev, Nikita Strelkov, Jeffrey Childress
  • Publication number: 20230292624
    Abstract: A magnetic sensor including a plurality of magnetoresistive elements; each magnetoresistive element including a ferromagnetic layer having a magnetization that is orientable at or above a threshold temperature; the magnetic sensor further includes a plasmonic structure destined to be irradiated by electromagnetic radiation and including a spatially periodic plasmonic array of metallic structures. The period of the plasmonic array and the lateral dimension of the metallic structures are adjusted to obtain plasmon resonance of the plasmonic structure for a given wavelength of the electromagnetic radiation. The plasmonic array is arranged in the magnetic sensor such as to heat the first ferromagnetic layer at or above the threshold temperature, from the enhanced absorption of the electromagnetic radiation by plasmon resonance. The present disclosure further concerns a system including the sensor and an emitting device configured to emit electromagnetic radiation.
    Type: Application
    Filed: May 27, 2021
    Publication date: September 14, 2023
    Inventors: Andrey Timopheev, Nikita Strelkov, Jeffrey Childress
  • Patent number: 11747411
    Abstract: A magnetic sensing circuit includes a circuit portion including: a main half-bridge including series-connected main tunnel magnetoresistive sensor elements TMR1 and TMR2; a first auxiliary half-bridge connected in parallel to the main half-bridge and including series-connected auxiliary tunnel magnetoresistive sensor elements TMR3 and TMR4 with an output voltage emerging from the connection between TMR1 and TMR3 and between TMR2 and TMR4; wherein a reference magnetization of the magnetoresistive sensor element TMR1 and TMR3 are respectively oriented substantially antiparallel with respect to a reference magnetization of the magnetoresistive sensor element TMR2 and TMR4; and wherein said first auxiliary half-bridge has a sensing axis that differs from the sensing axis of the main half bridge by an angle of about 180°/n, where n is the harmonic number to be canceled. The magnetic sensing circuit allows for sensing of external magnetic fields having high magnitude, with reduced angular error.
    Type: Grant
    Filed: November 29, 2019
    Date of Patent: September 5, 2023
    Assignee: CROCUS TECHNOLOGY SA
    Inventors: Andrey Timopheev, Romain Foissac
  • Publication number: 20230213597
    Abstract: Magnetic angular sensor element destined to sense an external magnetic field, including a magnetic tunnel junction containing a ferromagnetic pinned layer having a pinned magnetization, a ferromagnetic sensing layer, and a tunnel magnetoresistance barrier layer; the ferromagnetic sensing layer including a first sensing layer being in direct contact with the barrier layer and having a first sensing magnetization, a second sensing layer having a second sense magnetization, and a metallic spacer between the first sensing layer and the second sensing layer; wherein the metallic spacer is configured to provide an antiferromagnetic coupling between the first sensing magnetization and the second sensing magnetization such that the first sensing magnetization is oriented substantially antiparallel to the second sensing magnetization; the second sensing magnetization being larger than the first sensing magnetization, such that the second sensing magnetization is oriented in accordance with the direction of the externa
    Type: Application
    Filed: May 10, 2021
    Publication date: July 6, 2023
    Inventors: Andrey Timopheev, Jeffrey Childress, Nikita Strelkov
  • Publication number: 20230066027
    Abstract: A magnetoresistive sensor element including: a reference layer having a pinned reference magnetization; a sense layer having a free sense magnetization comprising a stable vortex configuration reversibly movable in accordance to an external magnetic field to be measured; a tunnel barrier layer between the reference layer and the sense layer; wherein the sense layer includes a first ferromagnetic sense portion in contact with the tunnel barrier layer and a second ferromagnetic sense portion in contact with the first ferromagnetic sense portion; the second ferromagnetic sense portion including a dilution element in a proportion such that a temperature dependence of a magnetic susceptibility of the sense layer substantially compensates a temperature dependence of a tunnel magnetoresistance of the magnetoresistive sensor element. Also, a method for manufacturing the magnetoresistive sensor element.
    Type: Application
    Filed: January 29, 2021
    Publication date: March 2, 2023
    Inventors: Léa Cuchet, Andrey Timopheev, Jeffrey Childress
  • Publication number: 20220268815
    Abstract: Magnetic current sensor, including: a sensor bridge circuit including a first and second half-bridges, each including two series-connected and diagonally opposed tunnel magnetoresistive (TMR) sensor elements, the TMR sensor elements including a reference layer oriented a single predetermined direction and a sense layer having a sense magnetization; a field line configured for passing a field current generating a magnetic field adapted for orienting the sense magnetization of the diagonally opposed TMR sensor elements of the first half-bridge and of the diagonally opposed TMR sensor elements of the second half-bridge in an opposite direction; such that a non-null differential voltage output between the TMR sensor elements of the first half-bridge and the TMR sensor elements of the second half-bridge is measurable when the field current is passed in the field line; the differential voltage output being insensitive to the presence of an external uniform magnetic field.
    Type: Application
    Filed: June 26, 2020
    Publication date: August 25, 2022
    Inventor: Andrey Timopheev