G01R33/06

Magnetic sensor arrangement

A magnetic sensor arrangement for determining information indicative of characteristics of a mechanical component has a first magnetic sensor to sense a signal associated with a periodic changing magnetic field generated by relative movement of the mechanical component and the magnetic sensor arrangement, a second magnetic sensor to sense that signal, wherein the first sensor is arranged a fixed distance from the second sensor, and a determination unit coupled to the first and second sensors to receive output signals of the first and second sensors. The output signal of the first sensor is phase-shifted to the output signal of the second sensor, to compare the output signals for determining the absolute phase of the signal associated with the periodic changing magnetic field, and to determine information indicative of characteristics of the mechanical component based on the determined absolute phase of the signal associated with the periodic changing magnetic field.

Single-chip magnetic field sensor bridge

A single-chip magnetic field sensor bridge, comprising a substrate, a reference arm, a sensing arm, shielding structures, and wire bond pads is disclosed. The reference arm and the sense arm respectively comprise at least two rows/columns of reference element strings and sense element strings formed by electrically connecting one or more identical magnetoresistive sensing elements. The reference element strings and the sense element strings are alternately arranged. The magnetoresistive sensing elements are AMR, GMR or TMR sensing elements. The reference element strings are provided with shielding structures thereon, and the sensing element strings are located in gaps between two adjacent shielding structures. The shielding structures are arrays of elongated strips composed of permalloy or another soft ferromagnetic material. The sensors can be implemented as one of three different bridge structures, called a quasi-bridge, a half-bridge, or a full-bridge. This single-chip magnetic field sensor bridge has the advantages of small size, low cost, high sensitivity, small offset, good linearity, and good temperature stability.

Absolute position encoder combining signals of two widely separated wavelengths
09772202 · 2017-09-26 · ·

An electronic absolute position encoder includes a scale extending along a measuring axis direction (MA) and including a signal modulating scale pattern defining a corresponding absolute range R along MA, a detector including sensing elements arranged along MA and configured to provide detector signals which respond to the signal modulating scale pattern, and a signal processing configuration that determines an absolute position of the detector along the scale based on the detector signals. The signal modulating scale pattern includes a coarse periodic pattern component as a function of position along the scale having a spatial wavelength λ.sub.C, wherein n*λ.sub.C=R and n is an integer, and a fine periodic pattern component as a function of position along the scale having a spatial wavelength λ.sub.F, wherein (mn+1)*λ.sub.F=R and m is an integer that is at least two. The wavelengths λ.sub.C and λ.sub.C may be widely separated.

Permanent magnet comprising an antiferromagnetic layer and a ferromagnetic layer

A permanent magnet comprising an antiferromagnetic layer and a ferromagnetic layer having a first sub-layer made of a first type of ferromagnetic material, the first type of ferromagnetic material being an at least partially crystallized alloy of iron and cobalt, and a second sub-layer made of a second type of ferromagnetic material, this second type of ferromagnetic material also being an alloy of iron and cobalt in which the proportion of face-centered cubic crystals is less than the proportion of face-centered cubic crystals in the first type of ferromagnetic material.

Permanent magnet comprising an antiferromagnetic layer and a ferromagnetic layer

A permanent magnet comprising an antiferromagnetic layer and a ferromagnetic layer having a first sub-layer made of a first type of ferromagnetic material, the first type of ferromagnetic material being an at least partially crystallized alloy of iron and cobalt, and a second sub-layer made of a second type of ferromagnetic material, this second type of ferromagnetic material also being an alloy of iron and cobalt in which the proportion of face-centered cubic crystals is less than the proportion of face-centered cubic crystals in the first type of ferromagnetic material.

Magnetic field measuring device with vibration compensation

A magnetic field measuring device with a holding body and a plurality of magnetoelectric cantilever sensors, each of which is designed to output one electrical voltage signal while it bends in the presence of a magnetic field, the cantilever sensors being non-positively connected or bonded to the holding body.

Magnetic field measuring device with vibration compensation

A magnetic field measuring device with a holding body and a plurality of magnetoelectric cantilever sensors, each of which is designed to output one electrical voltage signal while it bends in the presence of a magnetic field, the cantilever sensors being non-positively connected or bonded to the holding body.

Resonant inductive sensing with reduced noise folding
09810744 · 2017-11-07 · ·

A resonant inductive sensing system includes in the drive current signal path of the resonator a pulse shaper for noise reduction, including reducing noise resulting from down modulation of signal energy around harmonics of the oscillator (multiples of the resonance frequency), and from uncertainty in the duration of the oscillation period. The pulse shaper is configured so that, for each modulation period of the drive current, consecutive drive current pulses are substantially identical. In example embodiments, an inductance-to-digital conversion (IDC) unit includes drive circuitry configured to drive excitation current pulses to the resonator with a modulation period synchronized with a resonator oscillation frequency, and pulse shaping circuitry configured to pulse shape the drive current pulses so that each pair of drive current pulses within a modulation period are substantially identical.

Method for reset and stabilization control of a magnetic sensor

A magnitude and direction of at least one of a reset current and a second stabilization current (that produces a reset field and a second stabilization field, respectively) is determined that, when applied to an array of magnetic sense elements, minimizes the total required stabilization field and reset field during the operation of the magnetic sensor and the measurement of the external field. Therefore, the low field sensor operates optimally (with the highest sensitivity and the lowest power consumption) around the fixed external field operating point. The fixed external field is created by other components in the sensor device housing (such as speaker magnets) which have a high but static field with respect to the low (earth's) magnetic field that describes orientation information.

Vertical hall sensor circuit comprising stress compensation circuit
09766300 · 2017-09-19 · ·

A vertical Hall sensor circuit comprises an arrangement comprising a vertical Hall effect region of a first doping type, formed within a semiconductor substrate and having a stress dependency with respect to a Hall effect-related electrical characteristic. The vertical Hall sensor circuit further comprises a stress compensation circuit which comprises at least one of a lateral resistor arrangement and a vertical resistor arrangement. The lateral resistor arrangement has a first resistive element and a second resistive element, which are parallel to a surface of the semiconductor substrate and orthogonal to each other, for generating a stress-dependent lateral resistor arrangement signal on the basis of a reference signal inputted to the stress compensation circuit. The vertical resistor arrangement has a third resistive element of the first doping type for vertically conducting an electric current flow, for generating a stress-dependent vertical resistor arrangement signal on the basis of the reference signal. The vertical Hall sensor circuit further comprises a first circuit for providing a first signal to the arrangement, the first signal being based on at least one of the stress-dependent lateral resistor arrangement signal and the stress-dependent vertical resistor arrangement signal.