公开(公告)号：US20210247465A1

公开(公告)日：2021-08-12

申请号：US17228048

申请日：2021-04-12

Applicant: TDK CORPORATION

Inventor： Kenichi TAKANO ,  Hiraku HIRABAYASHI ,  Yuta SAITO

IPC: G01R33/00 ,  G01R33/09

Abstract: A magnetic field detection device of an embodiment of the disclosure includes: a first magnetic field detection element having a first resistance value increasing upon application of a first magnetic field in a first direction and decreasing upon application of a second magnetic field in a second direction; and a second magnetic field detection element having a second resistance value decreasing upon application of the first magnetic field and increasing upon application of the second magnetic field. The first and second magnetic field detection elements each include first and second magneto-resistive effect films coupled in series. The first magneto-resistive effect film has a first major-axis direction inclined at a first inclination angle relative to the first direction. The second magneto-resistive effect film has a second major-axis direction inclined at a second inclination angle relative to the first direction. The magnetic field detection device satisfies conditional expressions (1) and (2).

公开(公告)号：US20190128700A1

公开(公告)日：2019-05-02

申请号：US16170089

申请日：2018-10-25

Applicant: TDK Corporation

Inventor： Keisuke UCHIDA ,  Yuta SAITO

IPC: G01D5/16

Abstract: A magnetic sensor according to the invention has an element portion having a magnetoresistive effect and a magnetically sensitive axis that is directed in a predetermined direction, and a soft magnetic body that is arranged near the element portion and that faces the element portion along at least a part of a portion other than both end portions thereof, as viewed in a direction of the magnetically sensitive axis. The soft magnetic body has protruding surfaces that protrude toward the element portion at said both end portions.

公开(公告)号：US20230204630A1

公开(公告)日：2023-06-29

申请号：US18111170

申请日：2023-02-17

Applicant: TDK CORPORATION

Inventor： Yuta SAITO ,  Hiraku HIRABAYASHI

IPC: G01R15/20 ,  G01R31/364

CPC classification number: G01R15/207 ,  G01R15/205 ,  G01R31/364

Abstract: A magnetic sensor device includes a first detection circuit that generates a first detection signal, a coil through which a feedback current is passed to generate a cancellation magnetic field, a second detection circuit that generates a second detection signal having a correspondence with a value of the feedback current, and a control circuit that controls the feedback current. In a closed-loop operation, the control circuit controls the feedback current so that the first detection signal has a constant value. In an open-loop operation, the control circuit maintains the feedback current at a constant value.

公开(公告)号：US20220326320A1

公开(公告)日：2022-10-13

申请号：US17850391

申请日：2022-06-27

Applicant: TDK Corporation

Inventor： Yuta SAITO ,  Hiraku HIRABAYASHI ,  Yoshihiro KUDO

IPC: G01R33/09

Abstract: A magnetic sensor includes a magnetic sensor chip that includes a magnetoresistive effect element and a sealed part. The magnetoresistive effect element includes a free layer and a pinned layer. The sealed part has a first surface and a second surface, which is opposite the first surface. The shape of the sealed part in the plan view from the first surface side is substantially quadrilateral. The substantially quadrilateral shape has a first side and a second side, which are substantially parallel to each other. In the plan view, from the first surface side of the sealed part, the magnetization direction of the pinned layer, in a state in which the external magnetic field is not applied on the magnetoresistive effect element, is inclined with respect to an approximately straight line found through the least squares method using a plurality of points arbitrarily set on the first side.

公开(公告)号：US20220317210A1

公开(公告)日：2022-10-06

申请号：US17847694

申请日：2022-06-23

Applicant: TDK Corporation

Inventor： Yuta SAITO ,  Yoshihiro KUDO ,  Daisuke MIYAUCHI ,  Satoshi ABE

IPC: G01R33/09 ,  G01R1/20 ,  G01R15/20

Abstract: The current sensor comprises: a magnetic detecting device that is arranged in the vicinity of a conductor, to which a magnetic field to be measured induced by a current flowing through the conductor is applied, and that changes an electrical resistance in response to a change in the magnetic field to be measured; two coils that generate a canceling magnetic field to cancel the magnetic field to be measured and that are arranged in the vicinity of the magnetic detecting device; a shunt resistor, that is connected in series between the two coils, for detecting a current flowing through the coils; a first differential amplifier that amplifies the output signal of the magnetic detecting device and that supplies the current to induce the canceling magnetic field to the coils; and a second differential amplifier that amplifies the voltage across the shunt resistor and that outputs a measured voltage proportional to the current flowing through the conductor.

公开(公告)号：US20220187344A1

公开(公告)日：2022-06-16

申请号：US17686965

申请日：2022-03-04

Applicant: TDK Corporation

Inventor： Yuta SAITO ,  Kenichi TAKANO ,  HIRAKU HIRABAYASHI

IPC: G01R15/20 ,  G01R19/00 ,  G01R33/09

Abstract: A current sensor has: a magneto-resistive effect element which is arranged near a current line, to which a signal magnetic field is applied, the signal magnetic field being is induced by a current that flows in the current line, and which generates a magneto-resistive change in accordance with a change of the signal magnetic field; cancelling magnetic field generating means that is provided near the magneto-resistive effect element and that generates a cancelling magnetic field that cancels the signal magnetic field; a first soft magnetic body that is provided between the magneto-resistive effect element and the current line; and a pair of second soft magnetic bodies that are provided on both sides of the magneto-resistive effect element with regard to a magnetization detecting direction of the magneto-resistive effect element.

公开(公告)号：US20210208215A1

公开(公告)日：2021-07-08

申请号：US17205222

申请日：2021-03-18

Applicant: TDK Corporation

Inventor： Kenichi TAKANO ,  Yuta SAITO ,  Hiraku HIRABAYASHI

IPC: G01R33/09 ,  G11B5/39 ,  G11B5/31

Abstract: A magnetic sensor whose output characteristic is less sensitive to the environmental temperature is provided. Magnetic sensor 1 has free layer 24 whose magnetization direction changes in response to an external magnetic field, pinned layer 22 whose magnetization direction is fixed with respect to the external magnetic field, spacer layer 23 that is located between pinned layer 22 and free layer 24 and that exhibits a magnetoresistance effect, and at least one magnet film 25 that applies a bias magnetic field to free layer 24. The film thickness of the magnet film is 15 nm or more and 50 nm or less. The relationship of 0.7≤TC_HM/TC_FL≤1.05 is satisfied, where TC_HM is Curie temperature of the magnet film, and TC_FL is Curie temperature of the free layer.