Nxp B.v.

Dave Sebastiaan Kroekenstoel

Harry Neuteboom

Muhammad Kamran

Costantino Ligouras

Sergio Andrés Rueda Gómez

Rinze Ida Mechtildis Peter Meijer

Steven Mark Thoen

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 signal generator includes a first voltage generator, a second voltage generator, an operational amplifier, and an oscillator. The first voltage generator generates a first voltage, and the second voltage generator generates a second voltage. The operational amplifier generates an amplified error signal based on the first voltage and the second voltage, and the oscillator generates a periodic signal based on the amplified error signal. The first voltage generator and the second voltage generator are configured to generate their respective voltages based on the periodic signal. As a result, frequency deviation in the periodic signal may be corrected, for example, without increasing the source current of the oscillator or the gain of the operational amplifier. Also, improved phase noise performance may also be achieved through an increase in loop gain.

Feedback oscillator with multiple switched capacitors

Aspects are directed to a wireless communications approach in which a signal is conveyed via one of a number of particular frequency bands. In one example, a tank circuit includes an inductor and multiple capacitive circuits, and a driver circuit includes multiple buffers. One of the buffers is responsive to the input signal and another of the buffers is not responsive to the input signal. The driver circuit is configured to drive the tank circuit through a respective capacitive circuit while coupled to a respective buffer at a node of the inductor. A tuning-drive circuit drives the tank circuit for communicating in one band of a selectably-tunable frequency range. The tuning-drive circuit includes selectable (buffer and capacitor) portions configured to selectively couple to the node, for an overall drive strength and an overall tuning capacitance, and for tuning the tank circuit to a selected frequency band for wireless communication.

Circuit for inductive communications with multiple bands

A power supply circuit comprises an input for receiving a power supply from a battery and a DC/DC converter for supplying a converted voltage to a load. A regulator is used for controlling the DC/DC converter such that the current drawn from the converter is smoothed. A charge storage device at the output of the DC/DC converter enables delivery of a non-constant current to the load.

Power supply circuit using DC/DC converter

A device, e.g., a hearing aid, has an electronic circuit for wireless communication of a digital signal. The circuit has a driver driving an RLC tank. The driver has a plurality of inverters whose outputs are coupled to a node of the coil via a respective one of multiple capacitors in the tank. The circuit has a controller that selectively drives one or more of the inverters with the digital signal and connects the inputs of the other inverters to a supply voltage or ground. The tank has a further plurality of series arrangements of a further capacitor and a high-voltage switch connected between the node and ground. The controller is configured for controlling the high-voltage switches.

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Eindhoven, Netherlands

Dave Sebastiaan Kroekenstoel