Stmicroelectronics S.r.l.

Politecnico Di Milano

Commissariat a L'energie Atomique Et Aux Energies Alternatives

Commissariat À L'énergie Atomique Et Aux Énergies Alternatives

Giacomo Langfelder

Alessandro Tocchio

Carlo Valzasina

Gabriele Gattere

Giacomo Laghi

Philippe Robert

Marco Zamprogno

Dario Paci

Francesco Rizzini

Marco Gadola

Giuseppe Maiocchi

Luca Giuseppe Falorni

Guillaume Jourdan

Patrice Rey

Andrea Barbieri

Luca Molinari

Luca Guerinoni

Thierry Verdot

Patrick Fedeli

Raffaele Enrico Furceri

Cristiano Rocco Marra

Giorgio Mussi

Paolo Frigerio

Leonardo Gaffuri Pagani

Antonio F Longoni

Paola Carulli

Stefano Dellea

Valentina Zega

Matteo Gianollo

Andrea Buffoli

An inertial sensor including a substrate, a first pair of proof masses sensitive to rotation movements occurring around a first direction and a third direction, a second pair of proof masses sensitive to rotation movements occurring around a second direction and the third direction, an excitation device, four frames, a rotatable frame and a sensing system connected to the rotatable frame. This inertial sensor is characterized in that the excitation device is configured to force the first pair of proof masses and the second pair of proof masses into a motion going towards and away from the sensing system, and wherein the readout of the rotation movements occurring in each of the three directions is achieved with piezoelectric gauges.

3-axis gyroscope with improved performance

The invention relates to an inertial sensor () comprising a substrate extending along a drive excitation direction (x) and a detection direction (y) normal to each other, the device plane being perpendicular to a rotation direction (z), a first drive frame () and a second drive frame (), a first sense frame (), a second sense frame (), a sense lever () pivotably mounted around a rotation axis (), a sensing system comprising a strain gauge () mechanically stressed by the sense lever it is rotating around the rotation axis. The sense lever includes a central portion (), a first arm () and a second arm (), the central portion having a dimension along the detection direction called central width, the arms having a dimension along the detection direction called arm width, the central width being at least twice greater than the arm width.

Inertial navigation sensor with reduced footprint

In an embodiment a circuit includes an inertial measurement unit configured to be oscillated via a driving signal provided by driving circuitry, a lock-in amplifier configured to receive a sensing signal from the inertial measurement unit and a reference demodulation signal which is a function of the driving signal and provide an inertial measurement signal based on the sensing signal, wherein the reference demodulation signal is affected by a variable phase error, phase meter circuitry configured to receive the driving signal and the sensing signal and provide, as a function of a phase difference between the driving signal and the sensing signal, a phase correction signal for the reference demodulation signal and a correction node configured to apply the phase correction signal to the reference demodulation signal so that, in response to the phase correction signal being applied to the reference demodulation signal, the phase error is maintained in a vicinity of a reference value.

Inertial measurement circuit, corresponding device and method

Disclosed herein is a control system for a projection system, including a first subtractor receiving an input drive signal and a feedback signal and generating a first difference signal therefrom, the feedback signal being indicative of position of a quasi static micromirror of the projection system. A type-2 compensator receives the first difference signal and generates therefrom a first output signal. A derivative based controller receives the feedback signal and generates therefrom a second output signal. A second subtractor receives the first and second output signals and generates a second difference signal therefrom. The second difference signal serves to control a mirror driver of the projection system. A higher order resonance equalization circuit receives a pre-output signal from an analog front end of the projection system that is indicative of position of the quasi static micromirror, and generates the feedback signal therefrom.

Closed-loop position control of MEMS micromirrors

The accelerometric sensor has a suspended region, mobile with respect to a supporting structure, and a sensing assembly coupled to the suspended region and configured to detect a movement of the suspended region with respect to the supporting structure. The suspended region has a geometry variable between at least two configurations associated with respective centroids, different from each other. The suspended region is formed by a first region rotatably anchored to the supporting structure and by a second region coupled to the first region through elastic connection elements configured to allow a relative movement of the second region with respect to the first region. A driving assembly is coupled to the second region so as to control the relative movement of the latter with respect to the first region.

Accelerometric sensor in mems technology having high accuracy and low sensitivity to temperature and ageing

Piezoresistive detection resonant device comprising a substrate, a mobile par configured to move with respect the substrate, suspension elements suspending the mobile part to the substrate, a piezoresistive detection device to detect the motions of the mobile part, said piezoresistive detection device comprising at least one strain gauge, wherein the piezoresistive detection resonant device also comprises a folded spring with at least two spring arms, connected to the mobile part and configured to be deformed by the motion of the mobile part, the at least one gauge being suspended between the substrate and the folded spring in such manner that the deformation of the gauge is reduced compared to the motion of the mobile part.

Piezoresistive detection resonant device in particular with large vibration amplitude

A MEMS resonator system has a micromechanical resonant structure and an electronic processing circuit including a first resonant loop that excites a first vibrational mode of the structure and generates a first signal at a first resonance frequency. A compensation module compensates, as a function of a measurement of temperature variation, a first variation of the first resonance frequency caused by the temperature variation to generate a clock signal at a desired frequency that is stable relative to temperature. The electronic processing circuit further includes a second resonant loop, which excites a second vibrational mode of the structure and generates a second signal at a second resonance frequency. A temperature-sensing module receives the first and second signals and generates the measurement of temperature variation as a function of the first variation of the first resonance frequency and a second variation of the second resonance frequency caused by the temperature variation.

Microelectromechanical resonator system with improved stability with respect to temperature variations

An inertial sensor for sensing an external acceleration includes: a first and a second proof mass; a first and a second capacitor formed between first and second fixed electrodes and the first proof mass; a third and a fourth capacitor formed between third and fourth fixed electrodes and the second proof mass; a driving assembly configured to cause an antiphase oscillation of the first and second proof masses; a biasing circuit configured to bias the first and third capacitors, thus generating first variation of the oscillation frequency in a first time interval, and to bias the second and fourth capacitors, thus generating first variation of the oscillation frequency in a second time interval; a sensing assembly, configured to generate an differential output signal which is a function of a difference between a value of the oscillating frequency during the first time interval and a value of the oscillating frequency during the second time interval. Such differential output signal can be correlated to the value and direction of the external acceleration.

FM inertial sensor and method for operating the FM inertial sensor

In an embodiment, a clock generator has a variable-modulus frequency divider that receives a high-frequency clock signal and outputs a divided clock signal having a frequency controlled by a modulus-control signal generated by a temperature-compensation circuit. A jitter filter is coupled to the output of the variable-modulus frequency divider and to the temperature-compensation circuit and generates a compensated clock signal having switching edges that are delayed, with respect to the divided clock signal, by a time correlated to a quantization-error signal.

Ultra-low power, real time clock generator and jitter compensation method

A MEMS triaxial magnetic sensor device includes a sensing structure having: a substrate; an outer frame, which internally defines a window and is elastically coupled to first anchorages fixed with respect to the substrate by first elastic elements; a mobile structure arranged in the window, suspended above the substrate, which is elastically coupled to the outer frame by second elastic elements and carries a conductive path for flow of an electric current; and an elastic arrangement operatively coupled to the mobile structure. The mobile structure performs, due to the first and second elastic elements and the arrangement of elastic elements, first, second, and third sensing movements in response to Lorentz forces from first, second, and third magnetic-field components, respectively. The first, second, and third sensing movements are distinct and decoupled from one another.

MEMS triaxial magnetic sensor with improved configuration

Accelerometric sensor in MEMS technology having high accuracy and low sensitivity to temperature and ageing

A magnetic field sensor includes a die and a current generator in the die. The current generator generates a driving current. A Lorentz force transducer is also formed in the die and coupled to the current generator to obtain measurements of a magnetic field based upon the Lorentz force. The magnetic field has a resonance frequency and the current generator drives the Lorentz force sensor with the driving current having a non-zero frequency different from the resonance frequency.

Magnetic sensor including a Lorentz force transducer driven at a frequency different from the resonance frequency, and method for driving a Lorentz force transducer

A magnetic-field sensor, including: a die, a current generator in the die. The current generator generating a driving current. A Lorentz force transducer also in the die and being configured to obtain measurements of magnetic field based upon the Lorentz force is coupled to the current generator. The transducer having a resonance frequency. The current generator is such that the driving current has a non-zero frequency different from the resonance frequency.

Magnetic sensor including a lorentz force transducer driven at a frequency different from the resonance frequency, and method for driving a lorentz force transducer

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Milan, Italy

Giacomo Langfelder