440results about "Magnetic field offset compensation" patented technology

The present invention provides a method to compensate for the sensitivity drift of a magnetic field sensor for sensing a magnetic field. The magnetic field sensor comprises at least four electrodes. The method comprises a first step where a first set of two electrodes is used to bias the sensor and a second set of two electrodes is used to sense an output signal of the magnetic field sensor, and a second step where the second set of two electrodes is used to bias the sensor and the first set of two electrodes is used to sense an output signal of the magnetic field sensor. The method is characterized in that at least one of the first or the second step is subdivided in at least a first sub-step and a second sub-step. A reference magnetic field has first magnetic field parameters, e.g. a first amplitude and / or direction, in the first sub-step and second magnetic field parameters, a second amplitude and / or direction, in the second sub-step. An output signal is sensed in the first and in the second step, and within the first or the second step an output signal is sensed in the first and the second sub-step.

A magnetic field measurement system includes an array of magnetometers; at least one magnetic field generator configured to generate a compensation field across the array of magnetometers; and a controller coupled to the magnetometers and the at least one magnetic field generator and configured for adjusting a dynamic range and sensitivity of the array by adjusting a spatial variation of the compensation field to alter which of the magnetometers of the array operate in a measurement mode. Another magnetic field measurement system utilizes at least one magnetometer instead of the array. The controller is configured for adjusting a dynamic range and sensitivity of the array by adjusting a spatial variation of the compensation field to alter which of multiple domains within the at least one magnetometer operate in the measurement mode

The invention provides a single chip difference free layer push-pull type magnetic field sensor electric bridge and a preparation method thereof. The magnetic field sensor electric bridge comprises a substrate, a staggered soft magnetic flux concentrator array and a GMR spin valve or a TMR magnetic resistor sensor unit array which is placed on the substrate and has an X-direction magnetic sensitive direction. Each soft magnetic flux concentrator comprises edges parallel to the X axis, edges parallel to the Y axis and four corners, and the four corners are sequentially marked as A, B, C and D from the upper left position in the clockwise direction. Magnetic resistor sensor units are placed at the gaps between the soft magnetic flux concentrators. Meanwhile, the magnetic resistor sensor units corresponding to the corners A and the corners C of the soft magnetic flux concentrators and the magnetic resistor sensor units corresponding to the corners B and the corners D are defined as push magnetic resistor sensor units and pull magnetic resistor sensor units respectively. The push magnetic resistor sensor units are electrically connected to form one or more push arms, the pull magnetic sensor units are electrically connected to form one or more pull arms, and the push arms and the pull arms are electrically connected to form a push-pull type sensor bridge. According to the single chip difference free layer push-pull type magnetic field sensor electric bridge and the preparation method therefore, the power consumption is low, the magnetic field sensitivity is high, and a magnetic field in the Y direction can be measured.

A calibratable magnetic field sensor for sensing a first and a second spatial component of a magnetic field in a reference point, wherein the magnetic field includes a first and a second measurement field component and / or a first and a second calibration field component. The magnetic filed sensor includes a first sensor element arrangement including at least a first and a second sensor element for sensing the first magnetic field component, which includes a first measurement field component and / or a first calibration field component, with respect to a first spatial axis in the reference point. Furthermore, the magnetic field sensor includes a second sensor element arrangement for sensing the second magnetic field component, which includes a second measurement field component and / or a second calibration field component, with respect to a second spatial axis in the reference point. The magnetic filed sensor also includes an excitation line arranged with respect to the first sensor element arrangement so that, when impressing a default current into the excitation line, a pair of different asymmetrical default calibration field components in the first sensor element and in the second sensor element is generated with respect to the first spatial axis in the first sensor element arrangement, wherein the two spatial axes pass along linearly independent position vectors.

A magnetic shielded package includes a magnetic device, a first magnetic shield member, and a second magnetic shield member. The first magnetic shield member is disposed below the magnetic device. The second magnetic shield member is disposed on the first magnetic shield member so as to cover the magnetic device. An opening portion is formed in the first magnetic shield member (i) at such a position as not to be adjacent to an outer circumference of the first magnetic shield member or (ii) an upper wall of the second magnetic shield member.

A magnetic field measurement system that includes at least one magnetometer; at least one magnetic field generator; a processor coupled to the at least one magnetometer and the at least one magnetic field generator and configured to: measure an ambient background magnetic field using at least one of the at least one magnetometer in a first mode selected from a scalar mode or a vector mode; generate, in response to the measurement of the ambient background magnetic field, a compensation field using the at least one magnetic field generator; and measure a target magnetic field using at least one of the at least one magnetometer in a spin exchange relaxation free (SERF) mode which is different from the first mode.

The present invention relates to a magnetic field sensing device (50) comprising several functionally different layers (38, 60, 70), wherein a Wheatstone bridge layer (70) comprises at least two resistors (20) of a Wheatstone bridge (18), each resistor (20) comprises at least one magnetic field sensing element (10) in the form of a resistor subelement (22), and a flip conductor layer (38) comprising at least one flip conductor (30) for flipping the internal magnetization state of each magnetic field sensing element (10). The flip conductor (30) comprises a plurality of conductor stripes (32) being arranged on at least two different flip conductor sublayers (38-1, 38-2) of said flip conductor layer (38) and being electrically coupled with each other through vias.The multilayer arrangement of said flip conductor (30) provides a compact design of said magnetic field sensing device (50), such that a decreased power consumption, decreased inductance and improved sensitivity of the magnetic field sensing device can be achieved.

Magnetic field sensor having a vertical Hall sensor element arranged in a semiconductor substrate, and an exciting conductor arrangement having at least one exciting conductor, the exciting conductor being arranged within an exciting conductor plane which is spaced apart, in parallel to the substrate surface, from the vertical Hall sensor element at a vertical distance h1 having a tolerance range Δh1 which is due to the manufacturing process, and which exciting conductor further has a lateral distance d1 as an offset from a center position which is located, in relation to the substrate surface, perpendicularly to the vertical Hall sensor element, and the lateral distance d1 being dimensioned such that a vertical calibration component B1x of a magnetic flux density B1 created by the exciting conductor arrangement in the vertical Hall sensor element changes by less than 5% within the tolerance range Δh1 for the vertical distance h1.

A magnetic field sensor and a method include a modulator coupled in a feedback arrangement and operable to modulate a calibration feedback signal with a modulator clock signal having a selected frequency and a selected relative phase operable to remove a gain error in the magnetic field sensor and in the method.

There are provided an azimuth measurement device and its method for realizing an update of an offset calculated from the data acquired by azimuth measurement. A geomagnetism output measured by a 3-axis magnetic sensor is amplified and input to an A / D conversion section. A chopper section is arranged for switching the terminals for driving an X-axis, Y-axis and a Z-axis magnetic sensor and applies drive voltage output from a drive power source section to the X-axis, the Y-axis and the Z-axis magnetic sensor. The output amplified value amplified by the amplification section is converted from an analog signal to a digital signal by the ND conversion section and then is input to a sensitivity / offset correction calculation section. Output data from this sensitivity / offset correction calculation section is input to an azimuth calculation section and the corresponding azimuth information is output. A reliability information calculation section outputs reliability information.

Systems, methods, and computer-readable media for efficiently testing sensor assemblies are provided. A test station may be operative to test a three-axis magnetometer sensor assembly by holding the assembly at each one of three test orientations with respect to an electromagnet axis. At each particular test orientation for each particular sensor axis, a difference may be determined between any magnetic field sensed by that sensor axis during the application of a first magnetic field along the electromagnet axis and any magnetic field sensed by that sensor axis during the application of a second magnetic field along the electromagnet axis. Those determined differences may be leveraged with the magnitudes of the first and second magnetic fields and the vector component of the electromagnet axis on each one of the sensor axes at each one of the test orientations to determine the sensitivity performances for each one of the sensor axes.