Nxp B.v.

Costantino Ligouras

Harry Neuteboom

Dave Sebastiaan Kroekenstoel

Sergio Andrés Rueda Gómez

Muhammad Kamran

Rinze Ida Mechtildis Peter Meijer

Edwin Jan Schapendonk

Peng Zhao

A method and apparatus are described for bio-impedance measurement using voltage to current conversion. In one example, a bio-impedance transducer includes an input stage to receive a bio-impedance signal having an oscillating voltage from two electrodes, the electrodes being coupled to a body, a resistance across the two electrodes to determine an alternating current of the bio-impedance signal, a gain stage coupled to the resistance to amplify the alternating current, a down converter coupled to the gain stage to convert the amplified alternating current to a direct current bio-impedance signal, and an analog-to-digital converter coupled to the down converter to convert the direct current bio-impedance signal to a digital bio-impedance signal.

Bio-impedance measurement using voltage to current conversion

Embodiments of multi-mode sigma-delta analog-to-digital converter (ADC) circuits and a microphone circuit are disclosed. In an embodiment, a multi-mode sigma-delta ADC circuit includes a pair of operational transconductance amplifiers (OTAs), a filter connected to the pair of OTAs, a quantizer connected to the filter, a differential digital-to-analog converter (DAC) connected to the quantizer, and a controller configured to switch the multi-mode sigma-delta ADC circuit between a single-ended operational mode, a pseudo differential operational mode, and a full differential operational mode to improve common mode rejection (CMR) performance by controlling the pair of OTAs. An output of a microphone and a differential output of the differential DAC are inputted into input terminals of the pair of OTAs.

Multi-mode sigma-delta ADC circuit and microphone circuit having a multi-mode sigma-delta ADC circuit

Embodiments of sigma-delta analog-to-digital converter (ADC) circuits and a microphone circuit are disclosed. In an embodiment, a sigma-delta ADC circuit includes a pair of operational transconductance amplifiers (OTAs), a filter connected to the pair of OTAs, a quantizer connected to the filter, a differential digital-to-analog converter (DAC) connected to the quantizer, and a bias compensation circuit configured to measure a biasing condition of a first OTA of the pair of OTAs and to apply the biasing condition of the first OTA to a second OTA of the pair of OTAs to reduce Total Harmonic Distortion Plus Noise (THD+N) in the sigma-delta ADC circuit. An output of a microphone and a differential output of the differential DAC are inputted into input terminals of the pair of OTAs.

Sigma-delta ADC circuit with bias compensation and microphone circuit having a sigma-delta ADC circuit with bias compensation

A method and apparatus are described for a reconfigurable architecture analog front end architecture for electrochemical sensors. In one example, an analog front end includes an electrode driver stage coupled to electrodes of an electrochemical sensor, and measurement channels coupled to the electrode driver stage to receive an electrode signal from the electrodes of the electrochemical sensor and to generate measurement results, the measurement channels configured to switch configurations to perform different measurements.

Reconfigurable architecture analog front end for electrochemical sensors

Various embodiments relate to a detector circuit, including: a voltage source configured to produce a first voltage on a first output, a second voltage on a second output, and third voltage on a third output, wherein the first voltage is greater than the second voltage and the second voltage is greater than the third voltage; a first switch connected to the second output; a sampling capacitor connected to the switch, wherein the sampling capacitor is charged by the voltage source when the switch is closed; a first comparator with one input connected to the first output and a second input connected to the sampling capacitor; a second comparator with one input connected to the third output and a second input connected to the sampling capacitor; a multiplexer with a plurality of inputs configured to be connected to a plurality of terminals of an external circuit and an output connected to the sampling capacitor, the first input of the first comparator, and the first input of the second comparator; and a controller with inputs connected to the first comparator, the second comparator, and a clock generation unit, wherein the controller is configured to produce control signals to control the first switch and the multiplexer and wherein the controller is configured to produce an output signal indicting the presence of a current leak on one of the plurality of terminals.

Leakage and loading detector circuit

A method for digital-to-analog signal conversion with distributed reconstructive filtering includes receiving a digital code synchronous to a clock signal having a first frequency, determining next states of a plurality of digital-to-analog current elements based on the digital code, combining a plurality of currents to generate an output current, and generating the plurality of currents. Each of the plurality of currents is based on a corresponding control signal of a plurality of control signals. The method includes generating the plurality of control signals based on the next states of the plurality of digital-to-analog current elements. Each of the plurality of control signals selects a first voltage level, a second voltage level, or a transitioning voltage level for use by a corresponding digital-to-analog current element. The transitioning voltage level linearly transitions from the first voltage level to the second voltage level over a predetermined number of periods of the clock signal.

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Utrecht, Netherlands

Costantino Ligouras