Abstract: A rotation rate sensor, including at least: one oscillating mass, deflectable in a drive direction and in a detection direction oriented perpendicularly to the drive direction; one drive circuit for prompting a defined oscillatory movement of the oscillating mass in the drive direction; one circuit for detecting a measuring signal, which corresponds to the deflection of the oscillating mass in the detection direction; and one read-out circuit for reading out and pre-processing the measuring signal. The read-out circuit includes a demodulator, with which a useful signal and a quadrature signal are extractable from the measuring signal. The read-out circuit includes a sigma-delta A/D converter. An offset voltage is feedable to the sigma-delta A/D converter, which is selected in such a way that tonal artifacts in the frequency spectrum of the digitized useful signal are shifted into a frequency range outside of the bandwidths of the useful signal to be expected.

Abstract: A method for operating a capacitive MEMS sensor. The method includes: supplying a defined electrical potential on a deflectably mounted, seismic mass of the MEMS sensor; capacitively inducing a vibrational motion of the seismic mass with the aid of a clocked electrical control voltage; compensating for fluctuations in the supplied electrical potential on the seismic mass caused by the clocked electrical control voltage, by selectively charging and/or discharging an electrical storage element connected to the seismic mass in accordance with the frequency of the clocked electrical control voltage.

Abstract: A readout circuit for a capacitive differential sensor including periodic output signals. The readout circuit includes: one capacitance-to-voltage converter for output signals of the sensor; and one feedback circuit including a sampling unit and a filter unit, the sampling unit being configured to sample a differential signal of two oppositely-phased output signals of the capacitance-to-voltage converter and to generate a sampled differential signal, the filter unit being configured to average the sampled differential signals and to generate an averaged differential signal, and the feedback circuit being configured to feed the averaged differential signal as feedback into the capacitance-to-voltage converter. A sensor system including a readout circuit is also described.

Abstract: A method for operating a capacitive MEMS sensor. The method includes: supplying a defined electrical potential on a deflectably mounted, seismic mass of the MEMS sensor; capacitively inducing a vibrational motion of the seismic mass with the aid of a clocked electrical control voltage; compensating for fluctuations in the supplied electrical potential on the seismic mass caused by the clocked electrical control voltage, by selectively charging and/or discharging an electrical storage element connected to the seismic mass in accordance with the frequency of the clocked electrical control voltage.

Abstract: A rotation rate sensor, including at least: one oscillating mass, deflectable in a drive direction and in a detection direction oriented perpendicularly to the drive direction; one drive circuit for prompting a defined oscillatory movement of the oscillating mass in the drive direction; one circuit for detecting a measuring signal, which corresponds to the deflection of the oscillating mass in the detection direction; and one read-out circuit for reading out and pre-processing the measuring signal. The read-out circuit includes a demodulator, with which a useful signal and a quadrature signal are extractable from the measuring signal. The read-out circuit includes a sigma-delta A/D converter. An offset voltage is feedable to the sigma-delta A/D converter, which is selected in such a way that tonal artifacts in the frequency spectrum of the digitized useful signal are shifted into a frequency range outside of the bandwidths of the useful signal to be expected.

Abstract: In accordance with an embodiment, a digital microphone interface circuit includes a delta-sigma analog-to-digital converter (ADC) having an input configured to be coupled to a microphone, a digital lowpass filter coupled to an output of the delta-sigma ADC, and a digital sigma-delta modulator coupled to an output of the digital lowpass filter. The delta-sigma ADC, the digital lowpass filter, and the digital sigma-delta modulator are configured to operate at different sampling frequencies.

Abstract: In accordance with an embodiment, a digital microphone interface circuit includes a delta-sigma analog-to-digital converter (ADC) having an input configured to be coupled to a microphone, a digital lowpass filter coupled to an output of the delta-sigma ADC, and a digital sigma-delta modulator coupled to an output of the digital lowpass filter. The delta-sigma ADC, the digital lowpass filter, and the digital sigma-delta modulator are configured to operate at different sampling frequencies.

Abstract: A circuit for biasing a MEMS microphone includes a first group of serially-coupled transistors coupled between a first node and a second node, a second group of serially-coupled transistors coupled between the first node and the second node, and a voltage divider circuit coupled to the second node having a number of outputs, a first group of outputs being coupled to corresponding control nodes associated with the first group of serially-coupled transistors, and a second group of outputs different from the first group of outputs coupled to corresponding control nodes associated with the second group of serially-coupled transistors, the control nodes being either bulk nodes or gate nodes.

Abstract: A circuit for biasing a MEMS microphone includes a first group of serially-coupled transistors coupled between a first node and a second node, a second group of serially-coupled transistors coupled between the first node and the second node, and a voltage divider circuit coupled to the second node having a number of outputs, a first group of outputs being coupled to corresponding control nodes associated with the first group of serially-coupled transistors, and a second group of outputs different from the first group of outputs coupled to corresponding control nodes associated with the second group of serially-coupled transistors, the control nodes being either bulk nodes or gate nodes.

Abstract: According to an embodiment, a circuit includes a high-? resistor including a plurality of semiconductor junction devices coupled in series and a plurality of additional capacitances formed in parallel with the plurality of semiconductor junction devices. Each semiconductor junction device of the plurality of semiconductor junction devices includes a parasitic doped well capacitance configured to insert a parasitic zero in a noise transfer function of the high-? resistor. Each additional capacitance of the plurality of additional capacitances is configured to adjust a parasitic pole in the noise transfer function of the high-? resistor in order to compensate for the parasitic zero.

Abstract: According to an embodiment, a circuit includes a high-? resistor including a plurality of semiconductor junction devices coupled in series and a plurality of additional capacitances formed in parallel with the plurality of semiconductor junction devices. Each semiconductor junction device of the plurality of semiconductor junction devices includes a parasitic doped well capacitance configured to insert a parasitic zero in a noise transfer function of the high-? resistor. Each additional capacitance of the plurality of additional capacitances is configured to adjust a parasitic pole in the noise transfer function of the high-? resistor in order to compensate for the parasitic zero.

Abstract: A signal amplification method includes receiving, from a capacitive sensor, a first input signal by a first control terminal of a first transistor, and a second input signal by a first control terminal of a second transistor. The method also includes producing a first output signal, including amplifying a first signal at a first load path terminal of the first transistor using a first inverting amplifier having an output coupled to a resistance network, and producing a second output signal, including amplifying a second signal at a first load path terminal of the second transistor using a second inverting amplifier having an output coupled to the resistance network. The method also includes feeding back the first and second output signal to a second load path terminal of the first transistor and to a second load path terminal of the second transistor via the resistance network according to a pre-determined fraction.

Abstract: A signal amplification method includes receiving, from a capacitive sensor, a first input signal by a first control terminal of a first transistor, and a second input signal by a first control terminal of a second transistor. The method also includes producing a first output signal, including amplifying a first signal at a first load path terminal of the first transistor using a first inverting amplifier having an output coupled to a resistance network, and producing a second output signal, including amplifying a second signal at a first load path terminal of the second transistor using a second inverting amplifier having an output coupled to the resistance network. The method also includes feeding back the first and second output signal to a second load path terminal of the first transistor and to a second load path terminal of the second transistor via the resistance network according to a pre-determined fraction.

Abstract: In accordance with an embodiment, a cancelation circuit includes a current mirror and a low pass filter. The current mirror includes an input terminal configured to accept an input current comprising a first noise signal, a first mirrored output and a second mirrored output. The low pass filter includes an input coupled to the first mirrored output and an output coupled to the second mirrored output. A sum of a current from the second mirrored output and a current of from the output of the low pass filter includes a phase-inverted version of the first noise signal.

Abstract: In accordance with an embodiment, a cancelation circuit includes a current mirror and a low pass filter. The current mirror includes an input terminal configured to accept an input current comprising a first noise signal, a first mirrored output and a second mirrored output. The low pass filter includes an input coupled to the first mirrored output and an output coupled to the second mirrored output. A sum of a current from the second mirrored output and a current of from the output of the low pass filter includes a phase-inverted version of the first noise signal.