Abstract:
A microelectromechanical gyroscope includes: a first mass (107) oscillatable according to a first axis (X); an inertial sensor (6), including a second mass (108), drawn along by the first mass (107) and constrained so as to oscillate according to a second axis (Y), in response to a rotation (Ω) of the gyroscope (100); a driving device (103), coupled to the first mass (107) so as to form a feedback control loop (105) and configured to maintain the first mass (107) in oscillation at a resonance frequency (ω R ); and an open-loop reading device (104), coupled to the inertial sensor (6) for detecting displacements of the second mass (108) according to the second axis (Y). The driving device (103) includes a read signal generator (130), for supplying to the inertial sensor (6) at least one read signal (V S ) having the form of a square-wave signal of amplitude that sinusoidally varies with the resonance frequency (ω R ).
Abstract:
A microelectromechanical gyroscope includes: a microstructure (102) having a first mass (107), which can oscillate according to a first axis (X), and a second mass (108), constrained to the first mass (107) so as to oscillate according to a second axis (Y) in response to a rotation (Ω) of the microstructure (102); and a driving device (103), coupled to the microstructure (102) to maintain the first mass (107) in oscillation at a resonance frequency (ω R ). The driving device (103) is provided with a low-pass filter, (114) having a passband (PB) such that the resonance frequency (ω R ) is comprised in the passband (PB), and a disturbance frequency (ω D ) associated to disturbance signals (I ADD (t), V AO (t)) due to coupling between the first mass (107) and the second mass (108) is not comprised in the passband (PB).
Abstract:
A microelectromechanical gyroscope includes a microstructure (102), comprising a first mass (107) and a second mass (108), wherein the first mass (107) is oscillatable according to a first axis (X) and the second mass (108) is constrained to the first mass (107) so as to be drawn along by the first mass (107) according to the first axis (X) and to oscillate according to a second axis (Y), in response to a rotation (Ω) of the microstructure (102). A driving device (103) is coupled to the microstructure (102) to maintain the first mass (107) in oscillation at the driving frequency (ω R ), and a reading device (104) detects displacements of the second mass (108) according to the second axis (Y). The gyroscope is provided with a self-test actuation system (6d, 6e, 6h, 106) coupled to the second mass (108) for applying an electrostatic force (F E ) at the driving frequency (ω R ) so as to move the second mass (108) according to the second axis (Y).
Abstract:
A resonant micro-electro-mechanical system includes: a microstructure (102) having a mass (107), which is free to oscillate in accordance with a predetermined degree of freedom (X); and a driving device (103), coupled to the mass (107) for maintaining the mass (107) itself in oscillation at a resonance frequency (ω R ). The driving device (103) is provided with a differential sense amplifier (109), supplying first signals (V RD1 , V RD2 ) indicative of a velocity of oscillation of the mass (107), and an actuation and control stage (111, 112, 113, 116) supplying second signals (V FBD1 , V FBD2 ) for driving the mass (107) on the basis of the first signals (V RD1 , V RD2 ). The driving device (103) moreover includes a filtering circuit (110) of a high-pass type, which is connected between the differential sense amplifier (109) and the actuation and control stage (111, 112, 113, 116) and has a bandpass (B) that includes the resonance frequency (ω R ).
Abstract:
A microelectromechanical gyroscope includes a body (6) and a driving mass (7), which is movable with respect to the body (6) according to a driving axis (X) and is capacitively coupled to the body (6). The gyroscope moreover includes a driving device (3), which forms a microelectromechanical control loop (18) with the body (6) and the driving mass (7) and is configured for supplying to the driving mass (7) driving signals (V D1 , V D2 ) having a common-mode component (V CM ) and respective differential components so as to maintaining the driving mass (7) in oscillation according to the driving axis (X). The driving device (3) is provided with an actuation stage (23) configured for inverting in a controlled way the sign of the differential components of the driving signals (V D1 , V D2 ).
Abstract:
A method of protection from noise of a digital signal (Vcomp) generated by a comparator (1), comprising the steps of: generating an output signal (Vout) which switches from a first logic state to a second logic state at a first switching of logic state of the digital signal (Vcomp); detecting a change from the first logic state to the second logic state of the output signal (Vout); and inhibiting further switchings of the output signal (Vout) for a first time interval after change from the first logic state to the second logic state.
Abstract:
A demodulator includes input terminals (3a, 3b; 103a, 103b), for receiving an input signal (S M ), and an amplifier stage (4) having a gain (G). The input signal (S M ) is amplitude-modulated and is defined by a carrier signal (S CR ) at a carrier frequency (f CR ) and by a modulating signal (S M '). The demodulator includes, moreover, a gain-control stage (5; 105), coupled to the amplifier stage (4) for varying the gain (G) of the amplifier stage (4) according to a sinusoid of a frequency equal to the carrier frequency (f CR ), on the basis of the carrier signal (S CR ).
Abstract:
A band-pass filter made up by an operational amplifier (2) and by an input circuit. The input circuit is formed by a capacitive filtering element (C 1 ), connected to the input of the operational amplifier; a coupling switch (11), coupled between an input node (10) and the capacitive filtering element; a capacitive sampling element (C s ), coupled between the input of the filter and the input node; and a sampling switch (16), coupled between the input node and a reference-potential line. The coupling switch and the input sampling switch close in phase opposition according to a succession of undesired components sampling and sensing steps, so that the capacitive sampling element forms a sampler for sampling the undesired component in the undesired components sampling step, in the absence of the component of interest, and forms a subtractor of the undesired components from the input signal in the sensing step.
Abstract:
A MEMS gyroscope includes: a microstructure (2) having a fixed structure (6), a driving mass (7), movable with respect to the fixed structure (6) according to a driving axis (X), and a sensing mass (8), mechanically coupled to the driving mass (7) so as to be drawn in motion according to the driving axis (X) and movable with respect to the driving mass (7) according to a sensing axis (Y), in response to rotations of the microstructure (2); and a driving device (3), for keeping the driving mass (7) in oscillation with a driving frequency (ω D ). The driving device (3) includes a discrete-time sensing interface (20), for detecting a position (x) of the driving mass (7) with respect to the driving axis (X) and a control stage (21, 23, 24, 25) for controlling the driving frequency (ω D ) on the basis of the position (x) of the driving mass (7).
Abstract:
A microelectromechanical gyroscope includes a microstructure (102), comprising a first mass (107) and a second mass (108), wherein the first mass (107) is oscillatable according to a first axis (X) and the second mass (108) is constrained to the first mass (107) so as to be drawn along by the first mass (107) according to the first axis (X) and to oscillate according to a second axis (Y), in response to a rotation (Ω) of the microstructure (102). A driving device (103) is coupled to the microstructure (102) to maintain the first mass (107) in oscillation at the driving frequency (ω R ), and a reading device (104) detects displacements of the second mass (108) according to the second axis (Y). The gyroscope is provided with a self-test actuation system (6d, 6e, 6h, 106) coupled to the second mass (108) for applying an electrostatic force (F E ) at the driving frequency (ω R ) so as to move the second mass (108) according to the second axis (Y).