Melexis Technologies Sa

Melexis Technologies Nv

Universiteit Gent

Johan Raman

Pieter Rombouts

Gael Close

Appolonius Jacobus Van Der Wiel

Samuel Huber

Andreas Bonin

A position sensing device for measuring a position, comprises a position sensing device for measuring a position; a plurality of sensors arranged to produce sense signals each being a function of an input phase representative of a position to be measured; a combiner circuit arranged to generate an error signal by combining the sense signals according to an array of weight factors; a processing block including a loop filter to filter the error signal and arranged to output a phase value representative of the position; and a feedback loop comprising a feedback signal unit arranged for receiving the output phase value and for adjusting based on the received output phase value of the array of weight factors.

Position sensing device

A sensor system for measuring a physical quantity includes: a bridge sensor having at least two terminal pairs, a current source for applying a bias current between the bias terminal pair, resulting in a differential sensor signal on a readout terminal pair, wherein the differential sensor signal is indicative for the physical quantity, and an amplifier comprising a first input node and a second input node for receiving the differential signal and at least one output node, wherein the amplifier is configured for amplifying the differential sensor signal and putting the resulting signal on the at least one output node, wherein the sensor system is configured such that, in operation, the amplifier is powered by at least part of the bias current.

Bridge sensor biasing and readout system

A circuit for biasing and reading out a bridge sensor structure comprises at least two pairs of connection terminals. The circuit comprises an excitation signal generator for generating an excitation signal for biasing and/or exciting the bridge, in which the excitation signal is provided as a non-constant periodic continuous function of time, and a detection circuit for obtaining the sensor signal from the bridge sensor structure by electrically connecting the detection circuit to any pair of connection terminals while applying the excitation signal to another pair. The circuit comprises a switch unit for switching the electrical excitation signal and for switching the detection circuit. A controller controls the switch unit to switch the first pair from being connected to the excitation signal generator at a time when the generated excitation signal is in a predetermined signal range where the excitation signal value is substantially equal to zero.

Bridge sensor biasing and readout

A semiconductor amplifier circuit comprising an input block adapted for receiving a voltage signal to be amplified, an integrator circuit having an integrating capacitor providing a continuous-time signal representative for the integral of the voltage signal, a first feedback path comprising: a sample-and-hold block and a first feedback block, the first feedback path providing a proportional feedback signal upstream of the current integrator. The amplification factor is larger than 1 for a predefined frequency range. Charge stored on the integrating capacitor at the beginning of a sample period is linearly removed during one single sampling period in such a way that the absolute value of the charge is smaller at the end of the sampling period than at the beginning of the sample period when the voltage signal to be amplified is equal to zero.

Integration-based low noise amplifiers for sensors

A method of reading out a Hall plate which comprises at least 4 contacts. The method comprises: reading out two of the contacts while biasing two other contacts of the at least 4 contacts thereby obtaining a readout signal; switching biasing and readout contacts according to a random or pseudo-random sequence of phases, each phase corresponding with a different permutation of biasing and readout contacts selected from the at least 4 contacts of the Hall plate wherein the biasing and readout contacts are selected such that the readout signal is a measure for the magnetic field; processing of the readout signal to obtain a readout of the Hall plate representative for the magnetic field.

Randomized spinning of hall plates

A method of biasing and reading-out a passive resistive sensor structure having two excitation nodes and two readout nodes, comprises the steps of: a) determining a first state of a first capacitor corresponding to a first amount of charge biasing the sensor structure such that a biasing current flows through said first capacitor during a first time interval determining a second state of the first capacitor corresponding to a second amount of charge integrating or averaging the readout signal during a second time interval related to the first time interval, thereby obtaining an integrated or averaged readout signal determining the sensor readout signal based on the integrated or averaged readout signal and a change in state of the first capacitor.

Method and circuit for biasing and readout of resistive sensor structure

An analog-to-digital converter comprises a first quantizer arranged for yielding a first digital signal; an error signal generation block arranged for generating an error signal representative of a difference between an analog input signal and the first digital signal; an analog loop filter arranged for receiving the error signal; a second quantizer arranged for receiving an output signal of the analog loop filter and for outputting a second digital signal; a digital loop filter arranged for receiving the second digital signal and for providing an input signal to the first quantizer; and a recombiner block comprising a first recombination and a second recombination filter, and an adder circuit for adding outputs of the first and second recombination filters. The first and second recombination filters are selected to obtain an analog-to-digital converted output signal being less dependent on quantization noise caused by the first quantizer than a first digital signal.

Analog-to-digital converter

An offset compensation circuit comprises an error signal generation block arranged for receiving an input phase and an output phase, and for generating an error signal indicative of an error between the input phase and the output phase. Means are provided for combining the error signal with an offset compensation signal, yielding an offset compensated signal. A loop filter is arranged for receiving the offset compensated signal and for outputting the output phase. An offset compensation block is arranged for receiving the output phase and for determining the offset compensation signal. The offset compensation signal comprises at least a contribution proportional to a periodic function of the output phase.

Offset compensation circuit for a tracking loop

A method for providing offset compensation in a Hall sensor comprising at least one Hall element having a plate-shaped sensor element made of a doped semiconductor material, comprises using measurements on the Hall element itself. The method comprises obtaining a first readout signal (V) from the at least one Hall element which is substantially dependent on the magnetic field, obtaining a second readout signal (V) from the at least one Hall element which is substantially independent of the magnetic field, and using the second readout signal (V) for obtaining a prediction ({circumflex over (V)}) of the offset (V) on the first readout signal (V).

Hall sensor readout system with offset determination using the Hall element itself

A semiconductor circuit comprising an input block having a first chopper providing a chopped voltage signal, a first transconductance converting said chopped voltage signal into a chopped current signal, a second chopper providing a demodulated current signal, a current integrator having an integrating capacitor providing a continuous-time signal, a first feedback path comprising: a sample-and-hold block and a first feedback block, the first feedback path providing a proportional feedback signal upstream of the current integrator. The amplification factor is at least 2. Charge stored on the integrating capacitor at the beginning of a sample period is linearly removed during one single sampling period. Each chopper operates at a chopping frequency. The sample-and-hold-block operates at a sampling frequency equal to an integer times the chopping frequency.

Low noise amplifier circuit

A method for reading out a sensor unit having a first set of nodes and a second set of nodes and a symmetry which allows different configurations of excitation and sensing lead to a same readout. The method includes changing the readout configuration of the sensor unit by exchanging excitation and sensing between the first set of nodes and the second set of nodes, evaluating the similarity or deviation between measurement signals obtained in different readout configurations of the sensor unit, raising an error if the measurement signals differ more from one another than a predetermined value.

Method for sensor readout with redundancy-checking

A difference measurement circuit having a first port and a second port for connection to a first set of nodes and a second set of nodes of a sensor unit. The circuit further has switching units for switching excitation signals emanating from excitation nodes from being applied to the first set of nodes (A, B) via the first port to being applied to the second set of nodes via the second port and for switching differential measurement signals measured at sensing nodes from being obtained from the second set of nodes via the second port to being obtained from the first set of nodes via the first port. The circuit further includes redundancy testing circuitry for evaluating the similarity or deviation between measurement signals obtained in different states of the switching units.

Sensor readout with redundancy-checking

A method determines isotropic stress by means of a Hall element which includes a plate-shaped area made of a doped semiconductor material and comprises four contacts contacting the plate-shaped area and forming corners of a quadrangle, two neighboring corners of the quadrangle defining an edge thereof. At least one van der Pauw transresistance value in at least one van der Pauw measurement set-up of the Hall element is determined, wherein the four contacts of the Hall element form contact pairs, a contact pair comprising two contacts defining neighboring corners of the quadrangle. One contact pair supplies a current and the other contact pair measures a voltage. A relationship between the supplied current and the measured voltage defines the Van der Pauw transresistance value. The method comprises determining a stress signal which depends on the at least one Van der Pauw transresistance value and determining isotropic stress.

Method and device for sensing isotropic stress and providing a compensation for the piezo-hall effect

A difference measurement circuit including a first port and a second port for connection to a first set of nodes and a second set of nodes of a sensor unit. The circuit further includes switching units for switching excitation signals emanating from excitation nodes from being applied to the first set of nodes via the first port to being applied to the second set of nodes via the second port and for switching differential measurement signals measured at sensing nodes from being obtained from the second set of nodes via the second port to being obtained from the first set of nodes via the first port. A corresponding method is described. The circuit further includes redundancy testing circuitry for evaluating the similarity or deviation between measurement signals obtained in different states of the switching units.

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Knesselare, Belgium

Johan Raman