Abstract: The present invention discloses a design of a single-chip push-pull bridge sensor, composed of magnetoresistive elements, utilizing on-chip permanent magnets. The permanent magnets are oriented to preset magnetization directions of free layers of adjacent sensor bridge arms so that they point to different directions with respect the same sensing direction, enabling push-pull operation. The push-pull bridge sensor of the present invention is integrated on a single chip. Additionally, an on-chip coil is disclosed to reset or calibrate the magnetization directions of the free layers of the magnetoresistive elements.

Abstract: A magnetic angle encoder comprising counting wheels, with columnar ring-shaped permanent magnets coaxially mounted to the counting wheels, tunneling magnetoresistive angular displacement sensors, and a digital processing circuit. In the magnetic angle encoder, the tunneling magnetoresistive angular displacement sensors are located in a region within detection planes of the permanent magnets with an axial distance and a specific radial distance from the permanent magnets. Within this specific radius range, the rotating magnetic field angle (?) of the component of the magnetic field generated by the permanent magnets in the detection planes varies linearly with the rotation phase angle (?) of the permanent magnets. An electronic water meter is also disclosed, and it comprises a plurality of counting units and a digital processing circuit. The counting units contain counting wheels, permanent magnets, and tunneling magnetoresistive angular displacement sensors.

Abstract: The present invention discloses a magnetic field sensing device that utilizes a single coil for calibrating the response of the sensor to compensate for temperature dependent sensitivity drift and also for resetting the magnetic field sensor in order to eliminate hysteresis. The single coil configuration is advantageous since it reduces the size of the sensor chip by decreasing the number of contact pads on the chip and also because it wastes less space, which permits an increase in the density of the magnetoresistive elements on the sensor chip.

Abstract: The present invention discloses a design for a single-chip dual-axis magnetic field sensor, based on magnetic tunnel junction (MTJ) elements and permanent magnets integrated on a semiconductor substrate to produce two types of sensor bridges that detect orthogonal magnetic field components. The orthogonal magnetic field component detection capability results from the different types of sensor bridges that can be produced by varying the shape of the MTJ elements and the bias fields that can be created by permanent magnets. Because the permanent magnets can create orthogonal bias fields on the different sensor bridges, it is possible to use a single pinned layer to set direction for both sensor bridges. This is advantageous because it permits the two-axis sensor to be fabricated on a single semiconductor chip without the need for specialized processing technology such as local heating, or deposition of multiple magnetoresistive films with different pinned layers setting directions.

Abstract: A thin film magnetoresistive sensor for detecting a magnetic field components perpendicular and parallel to the plane of the sensor substrate is disclosed. The sensing element comprises a free layer, a reference layer, and a spacer layer between the free layer and the reference layer. The easy-axis magnetization, which is inherent to the material of the free layer, is arranged to be perpendicular to the plane of the sensor substrate. The magnetization direction of the reference layer is confined to a direction parallel to the substrate plane. The reference layer consists of a ferromagnetic layer exchange coupled to an antiferromagnetic layer, or consists of a ferromagnetic layer having a higher coercive force than that of the free layer. The spacer layer is composed of an insulating material or a conductive material. The magnetoresistive sensor further includes an array of aforementioned sensing elements coupled to an electronic device in order to provide three-axis sensing.

Abstract: A current sensor comprises a sensor bridge, with magnetic tunnel junction (MTJ) elements, a MTJ temperature compensation resistor, and a current lead integrated onto a chip. The current lead is positioned close to the sensor bridge, and it is used to carry the test current. A permanent magnet is arranged at the periphery of the MTJ temperature compensation resistor. The permanent magnet rigidly aligns the magnetization direction of the free layer of the MTJ temperature compensation resistor anti-parallel to the magnetization direction of a pinning layer. The sensor bridge is connected in series with the MTJ temperature compensation resistor to temperature compensate the sensor bridge. A magnetic field generated by the test current produces an output voltage at the output of the temperature compensated sensor bridge that is proportional to the test current value.

Abstract: Disclosed in the present invention is a low-power magnetoresistive switch sensor, comprising an internal reference voltage circuit, a multiplexer, a magnetoresistive bridge circuit, a comparison circuit, a voltage stabilization circuit, a digital control circuit, and a digital output circuit; one end of the internal reference voltage circuit is grounded while the other end of the internal reference voltage circuit is connected to the output end of the voltage stabilization circuit; the comparison circuit comprises one or more comparators, one end of the comparison circuit is electrically connected with the voltage stabilization circuit while the other end is grounded, the comparison circuit is provided with one or more input ends and one or more output ends, and the one or more output ends of the comparison circuit are electrically connected with one input ends of the digital control circuit; one end of the magnetoresistive bridge circuit is electrically connected with the output end of the voltage stabilizat

Abstract: A single-chip Z-axis linear magnetoresistive sensor is provided. The sensor comprises a substrate, magnetoresistive sensing elements, and flux guides, wherein the magnetoresistive sensing elements are mutually electrically connected to form push arms and pull arms of a bridge; the push arms and the pull arms are alternately arranged, and the magnetoresistive sensing elements on the push arms and the pull arms are respectively located at two sides beneath the flux guides; the magnetization direction of a pinning layer of each magnetoresistive sensing element is the same and is in an X-axis direction. An external magnetic field in a Z-axis direction is converted into a magnetic field with components in an X-axis direction by the flux guides, and thus the magnetoresistive sensing elements beneath the flux guides can detect this component.

Abstract: A multi-turn absolute magnetic encoder, comprising (M+1) counting units, a single-turn signal processing unit, and a multi-turn signal processing unit. Each counting unit comprises counting wheels with a cylindrical ring permanent magnet fixed thereon, and a tunneling magnetoresistive angular displacement sensor. The magnetoresistive angular displacement sensor is located within a region in a detection plane of the permanent magnet at within a specific radius range from the axis of the cylindrical ring permanent magnet, within the detection plane the angle of a component of a magnetic field generated by the permanent magnet is linearly proportional to the rotation angle of the cylindrical ring permanent magnet.

Abstract: A single chip push-pull bridge-type magnetic field sensor. The sensor comprises a substrate, bonding pads, magnetoresistance sensing elements, and flux concentrators, wherein the magnetoresistance sensing elements are positioned in the clearances of the adjacent flux concentrators, and the directions of the pinning layers of the magnetoresistance sensing elements are identical. The flux concentrators are divided into a push arm type and a pull arm type, the included angle between one type and an X-axis forward direction is positive, and the included angle between the other type and the X-axis forward direction is negative. The working principle of the sensor is that the magnetic field along the X-axis direction in the clearances of the flux concentrators are oppositely oriented. The sensor has the advantages of small size, low cost, simplicity in manufacturing, high sensitivity, good linearity, high sensitivity, wide working dynamic range, and the like.

Abstract: A single-package power meter is disclosed for measuring the power consumed by a load connected to an electrical conductor. The power meter is galvanically isolated from the electrical conductor through the use of magnetic sensors or through the combination of magnetic sensors and capacitors. Instantaneous power consumed at the load and other desired parameters are determined by measuring the voltage of the load and current flowing through the electrical conductor. Current is measured using a magnetic sensor to detect the magnetic field associated with the current flowing through the electrical conductor. Voltage is measured by one of two possible techniques involving magnetic sensors to measure the current flowing through a coil connected in parallel with a load, or through the use of a capacitively coupled voltage divider connected in parallel with the load.

Abstract: A magnetoresistive sensor bridge utilizing magnetic tunnel junctions is disclosed. The magnetoresistive sensor bridge is composed of one or more magnetic tunnel junction sensor chips to provide a half-bridge or full bridge sensor in a standard semiconductor package. The sensor chips may be arranged such that the pinned layers of the different chips are mutually anti-parallel to each other in order to form a push-pull bridge structure. The sensor chips are then interconnected using wire bonding. The chips can be wire-bonded to various standard semiconductor leadframes and packaged in inexpensive standard semiconductor packages. The bridge design may be push-pull or referenced. In the referenced case, the on-chip reference resistors may be implemented without magnetic shielding.

Abstract: A transducer is disclosed for detecting the AC and DC voltage difference between two nodes in an electrical circuit and electronically transmitting the measured voltage difference to an electrical system that is electrically isolated from the common mode potential of the two nodes. The voltage drop between two points in a circuit under test is determined by detecting the current flowing through a resistive shunt coil connected in parallel to the test points. Current through the resistive shunt coil is linearly proportional to the voltage difference between the test points, and it is detected by using a magnetic sensor that is separated from the shunt coil by an insulating dielectric barrier. The transducer can be packaged in a standard integrated circuit package in order to provide a small and low cost voltage transducer for test, measurement, control, and signal-isolation applications.

Abstract: A single-package bridge-type magnetic-field angle sensor comprising one or more pairs of magnetic tunnel junction sensor chips rotated relative to each other by 90 degrees in order to detect two magnetic field components in orthogonal directions respectively is disclosed. The magnetic-field angle sensor may comprise a pair of MTJ full-bridges or half-bridges interconnected with a semiconductor package lead. The magnetic-field angle sensor can be packaged into various low-cost standard semiconductor packages.

Abstract: A thin film magnetoresistive sensor for detecting a magnetic field components perpendicular and parallel to the plane of the sensor substrate is disclosed. The sensing element comprises a free layer, a reference layer, and a spacer layer between the free layer and the reference layer. The easy-axis magnetization inherent to the material of the free layer is arranged to be perpendicular to the plane of the sensor substrate. The magnetization direction of the reference layer is confined to a direction parallel to the substrate plane. The reference layer consists of a ferromagnetic layer exchange coupled to an antiferromagnetic layer, or consists of a ferromagnetic layer having a higher coercive force than that of the free layer. The spacer layer is composed of an insulating material or a conductive material. The magnetoresistive sensor further includes an array of aforementioned sensing elements coupled to an electronic device to provide three-axis sensing.

Abstract: The present invention discloses a design and manufacturing method for a single-chip magnetic sensor bridge. The sensor bridge comprises four magnetoresistive elements. The magnetization of the pinned layer of each of the four magnetoresistive elements is set in the same direction, but the magnetization directions of the free layers of the magnetoresistive elements on adjacent arms of the bridge are set at different angles with respect to the pinned layer magnetization direction. The absolute values of the angles of the magnetization directions of the free layers of all four magnetoresistive elements are the same with respect with their pinning layers. The disclosed magnetic biasing scheme enables the integration of a push-pull Wheatstone bridge magnetic field sensor on a single chip with better performance, lower cost, and easier manufacturability than conventional magnetoresistive sensor designs.

Abstract: A single package magnetoresistive angle sensor for use in measuring rotation angle of a magnet is disclosed. The magnetoresistive angle sensor comprises a pair of magnetoresistive sensor chips, wherein one of the chips is rotated by 180-degree rotation relative to the other. The magnetoresistive sensor chips are attached to a standard semiconductor package lead frame to form a single-axis push-pull full-bridge sensor. Each of the magnetoresistive sensor chips comprises a pair of magnetoresistance sensor arms. Each magnetoresistive sensor arm comprises one or more GMR or MTJ sensor elements. The GMR of MTR sensor elements utilize a pined layer. The element blocks of the magnetoresistive sensor electrically are interconnected and connected to the package leads by wirebonding. The magnetoresistive angle sensor can be packaged into various standard semiconductor package designs.

Abstract: Disclosed is a magnetoresistive magnetic field gradient sensor, comprising a substrate, a magnetoresistive bridge and a permanent magnet respectively disposed on the substrate; the magnetoresistive bridge comprises two or more magnetoresistive arms; each magnetoresistive arm consists of one or more magnetoresistive elements; each magnetoresistive element is provided with a magnetic pinning layer; the magnetic pinning layers of all the magnetoresistive elements have the same magnetic moment direction; the permanent magnet is disposed adjacent to each magnetoresistive arm to provide a bias field, and to zero the offset of the response curve of the magnetoresistive element; the magnetoresistive gradiometer includes wire bonding pads that can be electrically interconnected using wire bonding to an ASIC or to the lead frame of a semiconductor chip package.

Abstract: The present invention discloses a triaxial magnetoresistive sensor. It comprises a substrate integrated with a biaxial magnetic field sensor, a Z-axis sensor that has a sensing direction along Z-axis perpendicular to the two axes of the biaxial magnetic field sensor, and an ASIC. The biaxial magnetic field sensor comprises an X-axis bridge sensor and a Y-axis bridge sensor. The Z-axis sensor and the two-axis sensor are electrically interconnected with the ASIC. A single-chip implementation of the triaxial magnetic field sensor comprises a substrate, onto which a triaxial magnetic field sensor and an ASIC are stacked. The triaxial magnetic field sensor comprises an X-axis bridge sensor, a Y-axis bridge sensor, and a Z-axis bridge sensor. The above design provides a highly integrated sensor with high sensitivity, low power consumption, good linearity, wide dynamic range, excellent thermal stability, and low magnetic noise.

Abstract: The present invention discloses a MTJ triaxial magnetic field sensor, comprising an X-axis bridge sensor that has a sensing direction along an X-axis, a Y-axis bridge sensor that has a sensing direction along a Y-axis, a Z-axis sensor that has a sensing direction along a Z-axis, and an ASIC chip connected with and matched to the X-axis, Y-axis, and Z-axis sensor chips. The Z-axis sensor includes a substrate and MTJ magnetoresistive elements deposited on the substrate. The Z axis magnetic field sensor is attached to the ASIC chip along an attachment edge, and an angle is formed between the sensor side of the Z axis magnetic field sensor and the adjacent attachment edge. The attachment edge angle is an acute angle or an obtuse angle. The resulting X, Y, and Z axes are mutually orthogonal. The above design provides a highly integrated sensor with high sensitivity, low power consumption, good linearity, wide dynamic range, excellent thermal stability, and low noise.