Abstract:
Described herein is an inertial sensor (1) provided with a detection structure (9, 19) sensitive to a first, a second and a third component of acceleration (a x , a y , a z ) along respective directions of detection (x, y, z), and generating respective electrical quantities as a function of said components of acceleration. The detection structure (9, 19) supplies at output a resultant electrical quantity (C) obtained as combination of said electrical quantities, and correlated to the value of a resultant acceleration (a) acting on the inertial sensor (1), given by a vector sum of the components of acceleration (a x , a y , a z ) . In particular, the detection structure (9, 19) is of a microelectromechanical type, and comprises a mobile portion (2, 12) made of semiconductor material forming with a fixed portion (8, 18) a first, a second and a third detection capacitor, and an electrical-interconnection portion (10, 20), connecting the detection capacitors in parallel; the resultant electrical quantity (C) being the capacitance obtained from said connection in parallel.
Abstract:
Described herein is an inertial sensor (1) provided with a detection structure (9, 19) sensitive to a first, a second and a third component of acceleration (a x , a y , a z ) along respective directions of detection (x, y, z), and generating respective electrical quantities as a function of said components of acceleration. The detection structure (9, 19) supplies at output a resultant electrical quantity (C) obtained as combination of said electrical quantities, and correlated to the value of a resultant acceleration (a) acting on the inertial sensor (1), given by a vector sum of the components of acceleration (a x , a y , a z ) . In particular, the detection structure (9, 19) is of a microelectromechanical type, and comprises a mobile portion (2, 12) made of semiconductor material forming with a fixed portion (8, 18) a first, a second and a third detection capacitor, and an electrical-interconnection portion (10, 20), connecting the detection capacitors in parallel; the resultant electrical quantity (C) being the capacitance obtained from said connection in parallel.
Abstract:
Described herein is an inertial sensor (1) provided with a detection structure (9, 19) sensitive to a first, a second and a third component of acceleration (a x , a y , a z ) along respective directions of detection (x, y, z), and generating respective electrical quantities as a function of said components of acceleration. The detection structure (9, 19) supplies at output a resultant electrical quantity (C) obtained as combination of said electrical quantities, and correlated to the value of a resultant acceleration (a) acting on the inertial sensor (1), given by a vector sum of the components of acceleration (a x , a y , a z ) . In particular, the detection structure (9, 19) is of a microelectromechanical type, and comprises a mobile portion (2, 12) made of semiconductor material forming with a fixed portion (8, 18) a first, a second and a third detection capacitor, and an electrical-interconnection portion (10, 20), connecting the detection capacitors in parallel; the resultant electrical quantity (C) being the capacitance obtained from said connection in parallel.
Abstract:
A free-fall detector device includes an inertial sensor (8), a detection circuit (21) associated to the inertial sensor (8), and a signal source (20) for supplying a read signal to the inertial sensor (8). The device moreover includes: a storage element (30), selectively connectable to the detection circuit (21) for storing a feedback signal (V FBX ) generated by the detection circuit (21) in response to the read signal supplied to the inertial sensor (8); and a feedback circuit (32a, 32b, 24, 36) coupled to the storage element (30) for supplying the feedback signal (V FBX ) to the inertial sensor (8) so that the detection circuit (21) generates at least one detection signal (V XO ) in response to the feedback signal (V FBX ) supplied to the inertial sensor (8).
Abstract:
A read device of a capacitive sensor includes: a signal source (104, C1, C2) supplying an electrical read signal (V RD ) for driving the capacitive sensor (101); and a discrete-time sense circuit (107) for generating an electrical output signal (V OM ), correlated to variations of capacitance (ΔC S ) of the capacitive sensor (101), in response to variations of the electrical read signal (V RD ). The device moreover includes: a modulator stage (105, 106) for generating a modulated electrical read signal (V RDM ) on the basis of the electrical read signal (V RD ) and supplying the modulated electrical read signal (V RDM ) to the capacitive sensor (101); a demodulator stage (110), connected to the sense circuit (107), for demodulating the electrical output signal (V OM ) and generating a demodulated electrical output signal (V OM ); and a lowpass filtering stage (112) for generating a filtered electrical output signal (V OC ), on the basis of the modulated electrical output signal (V OM ).
Abstract:
A micro-electromechanical device includes a semiconductor body (5), in which at least one first microstructure (2) and one second microstructure (3) of reference are integrated. The first microstructure (2) and the second microstructure (3) are arranged in the body (5) so as to undergo equal strains as a result of thermal expansions of said body (5; 105; 205; 305). Furthermore, the first microstructure (2) is provided with movable parts (6) and fixed parts (7) with respect to the body (5), and the second microstructure (3) has a shape that is substantially symmetrical to the first microstructure (2) and is fixed with respect to the body (5).
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).