Abstract:
Described herein is a MEMS acoustic transducer device (42) having: a capacitive microelectromechanical sensing structure (1) ; and a biasing circuit (20), including a voltage-boosting circuit (9) that supplies a boosted voltage (V CP ) on an output terminal (9a), and an insulating circuit element (10), defining a high impedance, set between the output terminal (9a) and a terminal of the sensing structure (1), which defines a first high-impedance node (N 1 ) associated to the insulating circuit element (10). The biasing circuit (20) has: a pre-charge stage (24) that generates at least one first pre-charge voltage (V pre1 ) on a first output (Out 1 ) thereof, as a function of, and distinct from, the boosted voltage (V CP ); and at least one first switch element (SW 1 ), set between the first output (Out 1 ) and the first high-impedance node (N 1 ). The first switch element (SW 1 ) is operable for selectively connecting the first high-impedance node (N 1 ) to the first output (Out 1 ), during a phase of start-up of the biasing circuit (20), for biasing the first high-impedance node to the first pre-charge voltage.
Abstract:
A charge amplifier circuit couplable to a transducer (8) which generates an electrical charge varying as a function of an external stimulus, the charge amplifier circuit (30) including an amplification stage (18) having an input node (IN), couplable to the transducer, and an output node (OUT), the amplification stage biasing the input node (IN) at a first DC voltage (V CMI ). The charge amplifier circuit includes a feedback circuit (22, 32) with a feedback capacitor (20), electrically interposed between the input and output nodes of the amplification stage. The feedback circuit further comprises: a resistor (22) electrically coupled to the input node; and a level-shifter circuit (34, 36), electrically interposed between the resistor and the output node. The level-shifter circuit biases the output node at a second DC voltage (V CMO ), as a function of the difference between the second DC voltage and a reference voltage (V ref ).
Abstract:
Described herein is a MEMS acoustic transducer device (42) having: a capacitive microelectromechanical sensing structure (1) ; and a biasing circuit (20), including a voltage-boosting circuit (9) that supplies a boosted voltage (V CP ) on an output terminal (9a), and an insulating circuit element (10), defining a high impedance, set between the output terminal (9a) and a terminal of the sensing structure (1), which defines a first high-impedance node (N 1 ) associated to the insulating circuit element (10). The biasing circuit (20) has: a pre-charge stage (24) that generates at least one first pre-charge voltage (V pre1 ) on a first output (Out 1 ) thereof, as a function of, and distinct from, the boosted voltage (V CP ); and at least one first switch element (SW 1 ), set between the first output (Out 1 ) and the first high-impedance node (N 1 ). The first switch element (SW 1 ) is operable for selectively connecting the first high-impedance node (N 1 ) to the first output (Out 1 ), during a phase of start-up of the biasing circuit (20), for biasing the first high-impedance node to the first pre-charge voltage.