Stmicroelectronics S.r.l.

Invensense, Inc.

St-ericsson Sa

Stmicroelectronics International N.v.

Oct Circuit Technologies International Limited

Carlo Pinna

Germano Nicollini

Sriraman Dakshinamurthy

Ronak Chetan Desai

Alessandro Mecchia

Sergio Pernici

Angelo Nagari

Paolo Pesenti

Federico Guanziroli

Doruk Senkal

Federico Mazzarella

Vito Avantaggiati

Ali Shirvani

Massimo Orio

An algorithm and architecture for sense transfer function estimation injects one or more test signals from a signal generator into a MEMS gyroscope to detect an output signal (e.g., proof mass output sense signal), including an in-phase (e.g., Coriolis) component and a quadrature component. The in-phase and quadrature components are encoded with reference signals to determine phase and/or gain variation and are processed via a variety of components (e.g., matrix rotation, digital gain, tones demodulator, transfer function errors estimation, etc.) to estimate a sense transfer function of the MEMS (e.g., H(f)) and corresponding phase and/or gain offset of H(f). The in-phase and quadrature components are also compensated for phase and/or gain offset by system components.

4-points phase and sensitivity estimation algorithm and related architecture

Facilitating minimization of non-linearity effects of a delay of a capacitance-to-voltage (C2V) converter on an output of a gyroscope is presented herein. A sense output signal of a sense mass of the gyroscope and a drive output signal of a drive mass of the gyroscope are electronically coupled to respective analog-to-digital converter (ADC) inputs of bandpass sigma-delta ADCs of the gyroscope. The bandpass sigma-delta ADCs include respective C2V converters that are electronically coupled, via respective feedback loops, to the respective ADC inputs to facilitate reductions of respective propagation delays of the bandpass sigma-delta ADCs. Respective ADC outputs of the bandpass sigma-delta ADCs are electronically coupled to demodulator inputs of a demodulator of the gyroscope that transforms the sense output into an output of the MEMS gyroscope representing an external stimulus that has been applied to the sense mass.

Minimizing a delay of a capacitance-to-voltage converter of a gyroscope by including such converter within a bandpass sigma-delta analog-to-digital converter of the gyroscope

Microelectromechanical systems (MEMS) gyroscopes and related sense frequency tracking techniques are described. Various embodiments facilitate sense frequency tracking and offset and/or sensitivity change compensation. Exemplary embodiments can comprise receiving a sense signal at an output of a MEMS gyroscope and determining a sense resonant frequency of the sense signal. In addition, exemplary methods can comprise generating an input sine wave with a frequency of the sense resonant frequency of the sense signal injecting the input sine wave into the MEMS gyroscope, to facilitate sense frequency tracking.

Microelectromechanical systems (MEMS) gyroscope sense frequency tracking

Microelectromechanical systems (MEMS) gyroscopes and related measurement and calibration techniques are described. Various embodiments facilitate phase estimation of an ideal phase for a demodulator mixer associated with an exemplary MEMS gyroscope using quadrature tuning, which can improve offset performance over life time for exemplary MEMS gyroscopes. Exemplary embodiments can comprise adjusting a quadrature component of an exemplary MEMS gyroscope sense signal, measuring a change in offset of the exemplary MEMS gyroscope at an output of a demodulator mixer associated with the exemplary MEMS gyroscope, estimating a phase error between the quadrature component and a demodulation phase angle of the demodulator mixer based on the change in the offset, and periodically adjusting the demodulation phase angle of the demodulator mixer based on the phase error.

Microelectromechanical systems (MEMS) gyroscope calibration

The present disclosure refers to a digital microphone device providing a single-bit Pulse Density Modulation PDM output signal. The digital microphone comprises a microphone, arranged to convert an acoustic input signal into an analog electrical signal, and a preamplifier, having a variable gain, arranged to receive the analog electrical signal and to provide an amplified analog electrical signal, depending on the variable gain. The variable gain depends on a gain control signal. The digital microphone further comprises an Analog-to-Digital Converter block, arranged to receive the amplified analog electrical signal and to convert it into a respective digital signal; and a compensation block, arranged to receive the digital signal and to perform a digital operation on such digital signal, on the basis of a compensation signal, to generate a compensated signal. Furthermore, the digital microphone comprises an Automatic Gain Controller block, arranged to detect the digital signal and to generate said gain control signal, on the basis of the detected digital signal. The Automatic Gain Controller block is further arranged to generate the compensation signal, on the basis of the control signal, and to provide the compensation signal to the compensation block, to compensate a variation of the digital signal resulting from the variable gain of the preamplifier. Finally, the digital microphone device comprises a conversion block, arranged to receive the compensated signal and to convert it into the single-bit PDM output signal.

Digital microphone device with extended dynamic range

The invention relates to an electronic integrated amplifier for driving an acoustic transducer. The amplifier comprises two differential input terminals to receive an input signal and a first and a second output terminal to provide an output signal to the transducer. In addition, the amplifier comprises an operational amplifier having an input end including differential inputs and an output end operatively associated with the first and second output terminals. A pair of input resistors connect the two differential input terminals to two intermediate terminals, respectively. A pair of feedback resistors connect the first and second output terminals to the two intermediate terminals, respectively. The integrated amplifier also comprises means for high-pass filtering the input signal. Such filtering means is characterized in that it comprises an input element interposed between said intermediate terminals and the input end of the operational amplifier, and a feedback element connected between the input end and the output end of the same operational amplifier.

Integrated amplifier for driving acoustic transducers

A multi-level sigma-delta Analog to Digital converter provides multi-level outputs using a quantizer with reduced quantization levels. The converter comprises a direct path comprising a computation block, an analog integrator, a digital integrator and the quantizer with reduced quantization levels. Further, the converter comprises a feedback path arranged to provide to the computation block a feedback analog signal. The feedback analog signal is injected via the feedback path and the computation block directly at the input terminal of the quantizer. The converter allows reduction of the complexity of the quantizer.

Multi-level sigma-delta ADC with reduced quantization levels

A multi-level sigma-delta Analog to Digital converter provides multi-level outputs using a quantizer with reduced quantization levels. The converter comprises a direct path comprising a computation block, an analog integrator and the quantizer with reduced quantization levels. Further, the converter comprises a feedback path arranged to provide to the computation block a feedback analog signal. The direct path comprises a first amplification block having a gain factor which is the inverse of the gain factor of a second amplification block of the feedback path. The converter allows reduction of the complexity of the quantizer.

The invention relates to a two stage class AB operational amplifier for driving a load, comprising at least an input stage comprising differential input terminals and an output terminal to provide a driving signal. In addition, the operational amplifier comprises an output stage comprising a first and second input terminals operatively associated to the input stage to be driven on the basis of said driving signal and a driving circuit operatively interposed between said input stage and the output stage. The operational amplifier is characterized in that the driving circuit comprises a first portion comprising at least one resistor operatively connected between a first reference potential via a first circuitry block comprising a PMOS transistor and a second reference potential via a second circuitry block comprising a NMOS transistor. The voltage drop on said at least a first resistor is fixed to a value depending on said first and second reference potentials and the gate-source voltages of said PMOS and NMOS transistors, respectively. The driving circuit further comprises a second portion comprising a first resistor and a second resistor having first terminals connected one another in a common terminal which is connected to the output terminal of the input stage. Said first resistor has a second terminal connected the first input terminal of the output stage and said second resistor has a second terminal connected to the second input terminal of the output stage. Said second terminals of the first and second resistors (R') are connected to the first reference potential via a third circuitry block and to the second reference potential (GND) via a fourth circuitry block, respectively. Said third (MW, M) and fourth (M, MX) circuitry blocks are arranged to be operatively connected to said first and second circuitry blocks, respectively, so that the voltage drop between the second terminals is substantially equal to the value of the voltage drop (VR) across said at least one resistor.

Two-stage class AB operational amplifier

An electric circuit includes a supply terminal to receive an outer supply voltage and a voltage regulator coupled to the supply terminal and to provide supply and resting voltages. A lock-out circuit is switchable between active and inactive states and receives the supply voltage at a supply node to generate, in the active state, an output voltage on a output terminal thereof. A protection circuit protects against electrostatic discharge, having at least one first diode coupled between the supply node and the output terminal. A cut-off electronic lock couples, in the inactive state, the supply node to the supply terminal by reverse biasing the at least one first diode to make a voltage of the output terminal float.

Electric circuit with protection against overvoltages

A single-ended or differential single-stage, or multi-stage sigma-delta analog-to-digital converter includes at least one switched-capacitor integrator comprising a switched-capacitor network receiving as input a signal to be sampled, and an amplifier coupled in cascade to the switched-capacitor network. A circuit is coupled to the amplifier for feeding an analog dither signal to a virtual ground of the amplifier.

Method of adding a dither signal in output to the last integrator of a sigma-delta converter and relative sigma-delta converter

A boosted sampling circuit that is relatively straightforward to form is provided, as well as a corresponding method for driving the same. The input voltage applied to the boosted sampling circuit may be equal to a supply voltage or may be greater than a maximum voltage level allowed by the prior art circuits. This result is attained by connecting the control nodes of a plurality of switches to the input node while a first control phase is active, and by connecting a current terminal of another switch to a biasing voltage for protecting it from breakdowns.

Boosted sampling circuit and relative method of driving

The boosted switch device comprises an input terminal and an output terminal; a supply line set to a supply potential; a ground line set to a ground potential; a transistor connected between the input and output terminals; a capacitor; and a switch device connecting the capacitor between the supply line and the ground line, when the transistor is off, and between the input terminal and the control terminal of the transistor, when the transistor is on.

Boosted switch device for a sampler of an analog/digital converter, and operating method thereof

A digital decimation filter includes a set of cascaded integrator stages for generating a first signal comprised of bit words including a first number of bits as well as a set of cascaded derivative stages for receiving said first signal and generating therefrom an output comprised of bit words including a second number of bits. The second number of bits is smaller than said first number of bits and a bit discarding unit is located downstream of the integrator stages and upstream of the derivative stages for discarding a given number of least significant bits from the bit words of the first signal before this is received by the derivative stages. Said given number is defined as the difference between said first and said second number of bits.

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Milan, Italy

Carlo Pinna