Abstract: A FBDDA amplifier comprising: a first differential input stage, which receives an input voltage; a second differential input stage, which receives a common-mode voltage; a first resistive-degeneration group coupled to the first differential input; a second resistive-degeneration group coupled to the second differential input; a differential output stage, generating an output voltage; a first switch coupled in parallel to the first resistive-degeneration group; and a second switch coupled in parallel to the second resistive-degeneration group. The first and second switches are driven into the closed state when the voltage input assumes a first value such that said first input stage operates in the linear region, and are driven into the open state when the voltage input assumes a second value, higher than the first value, such that the first input stage operates in a non-linear region.

Abstract: An amplifier circuit, for a capacitive acoustic transducer defining a sensing capacitor that generates a sensing signal as a function of an acoustic signal, has a first input terminal and a second input terminal, which are coupled to the sensing capacitor and: a dummy capacitor, which has a capacitance corresponding to a capacitance at rest of the sensing capacitor and a first terminal connected to the first input terminal; a first buffer amplifier, which is coupled at input to the second input terminal and defines a first differential output of the circuit; a second buffer amplifier, which is coupled at input to a second terminal of the dummy capacitor and defines a second differential output of the circuit; and a feedback stage, which is coupled between the differential outputs and the first input terminal, for feeding back onto the first input terminal a feedback signal, which has an amplitude that is a function of the sensing signal and is in phase opposition with respect thereto.

Abstract: An amplifier circuit, for a capacitive acoustic transducer defining a sensing capacitor that generates a sensing signal as a function of an acoustic signal, has a first input terminal and a second input terminal, which are coupled to the sensing capacitor and: a dummy capacitor, which has a capacitance corresponding to a capacitance at rest of the sensing capacitor and a first terminal connected to the first input terminal; a first buffer amplifier, which is coupled at input to the second input terminal and defines a first differential output of the circuit; a second buffer amplifier, which is coupled at input to a second terminal of the dummy capacitor and defines a second differential output of the circuit; and a feedback stage, which is coupled between the differential outputs and the first input terminal, for feeding back onto the first input terminal a feedback signal, which has an amplitude that is a function of the sensing signal and is in phase opposition with respect thereto.

Abstract: A microphone preamplifier circuit is adapted to be connected to a microphone circuit, the microphone circuit including a microphone and at least one output node. The microphone preamplifier circuit includes a preamplifier including: an operational amplifier having at least one input and at least one output; at least one input DC decoupling capacitor connected to the at least one input of the operational amplifier; at least one feedback capacitor connected between the input and the output of the operational amplifier in order to set together with the at least one input DC decoupling capacitor a gain value of the preamplifier circuit; and first and second feed nodes adapted to be fed by first and second bias voltages respectively. The preamplifier further includes at least one switched capacitor adapted to be selectively and alternatively connected in response to a clock signal: between the at least one input and the at least one output of the operational amplifier; and between the first and second feed nodes.

Abstract: An amplifier circuit, for a capacitive acoustic transducer defining a sensing capacitor that generates a sensing signal as a function of an acoustic signal, has a first input terminal and a second input terminal, which are coupled to the sensing capacitor and: a dummy capacitor, which has a capacitance corresponding to a capacitance at rest of the sensing capacitor and a first terminal connected to the first input terminal; a first buffer amplifier, which is coupled at input to the second input terminal and defines a first differential output of the circuit; a second buffer amplifier, which is coupled at input to a second terminal of the dummy capacitor and defines a second differential output of the circuit; and a feedback stage, which is coupled between the differential outputs and the first input terminal, for feeding back onto the first input terminal a feedback signal, which has an amplitude that is a function of the sensing signal and is in phase opposition with respect thereto.

Abstract: A MEMS acoustic transducer device has a capacitive microelectromechanical sensing structure and a biasing circuit. The biasing circuit includes a voltage-boosting circuit that supplies a boosted voltage on an output terminal, and a high-impedance insulating circuit element set between the output terminal and a terminal of the sensing structure, which defines a first high-impedance node associated with the insulating circuit element. The biasing circuit has: a pre-charge stage that generates a first pre-charge voltage on a first output thereof, as a function of, and distinct from, the boosted voltage; and a first switch element set between the first output and the first high-impedance node. The first switch element is operable for selectively connecting the first high-impedance node to the first output, during a phase of start-up of the biasing circuit, for biasing the first high-impedance node to the first pre-charge voltage.

Abstract: A MEMS acoustic transducer has: a detection structure, which generates an electrical detection quantity as a function of a detected acoustic signal; and an electronic interface circuit, which is operatively coupled to the detection structure and generates an electrical output quantity as a function of the electrical detection quantity.

Abstract: A FBDDA amplifier comprising: a first differential input stage, which receives an input voltage; a second differential input stage, which receives a common-mode voltage; a first resistive-degeneration group coupled to the first differential input; a second resistive-degeneration group coupled to the second differential input; a differential output stage, generating an output voltage; a first switch coupled in parallel to the first resistive-degeneration group; and a second switch coupled in parallel to the second resistive-degeneration group. The first and second switches are driven into the closed state when the voltage input assumes a first value such that said first input stage operates in the linear region, and are driven into the open state when the voltage input assumes a second value, higher than the first value, such that the first input stage operates in a non-linear region.

Abstract: A low-noise reference voltages distribution circuit has a multi-output voltage-to-current converter configured to receive an input reference voltage and to provide a plurality of output reference currents to be converted into a plurality of local reference voltages by corresponding receiving circuits. The converter includes an input section, an output section and a low-pass filter. The input section generates a reference current based on the input reference voltage, and has a current mirror input transistor having a voltage controlled input terminal. The output section includes a plurality of current mirror output transistors outputting reference currents to the plurality of reference currents, respectively, and having a voltage controlled input terminal connected to a common input node. The low-pass filter has an input node connected to the voltage controlled input terminal of the current mirror input transistor and an output node connected to the common input node.

Abstract: An interface circuit is provided that is adapted to connect a microphone circuit to a preamplifier. The microphone circuit has a microphone and at least an output node and the preamplifier has at least an input node connected to the output node by the interface circuit. The interface circuit has at least a decoupling capacitor for DC decoupling the input node from the output node. The decoupling is connected between the input node and the output node. The interface circuit has at least one active circuit, comprising a resistor connected the decoupling capacitor. The resistor acts as part of a resistance multiplier and has an equivalent resistance that together with the decoupling capacitor defines a high-pass filter connected between the microphone and the preamplifier. The interface circuit may also have a biasing circuit connected to the resistor.

Abstract: A MEMS acoustic transducer device has a capacitive microelectromechanical sensing structure and a biasing circuit. The biasing circuit includes a voltage-boosting circuit that supplies a boosted voltage on an output terminal, and a high-impedance insulating circuit element set between the output terminal and a terminal of the sensing structure, which defines a first high-impedance node associated with the insulating circuit element. The biasing circuit has: a pre-charge stage that generates a first pre-charge voltage on a first output thereof, as a function of, and distinct from, the boosted voltage; and a first switch element set between the first output and the first high-impedance node. The first switch element is operable for selectively connecting the first high-impedance node to the first output, during a phase of start-up of the biasing circuit, for biasing the first high-impedance node to the first pre-charge voltage.

Abstract: There is described a shutter for a valve for controlling an air flow; shutter is selectively rotatable about an axis and adapted to be housed inside a body of valve, and comprises a surface disposed about axis; surface comprises at least one first curved portion shaped eccentrically relative to axis so as to define, in use and together with body, at least one first passage for the air flow.

Abstract: The invention relates to a two-stage operational amplifier (400) in class AB for driving a load (RLB, RLA) comprising: an input stage (401) comprising differential input terminals (IN, 1P) and a first differential output terminal (O1P) and a second differential output terminal (O1N) for providing a first differential driving signal (Out1P) and a second differential driving signal (Out1N), respectively; an output stage (402) comprising a first output branch (403) having a first differential input terminal (I1P) operatively connected to the first differential output terminal (O1P) of the input stage (401) to receive the first differential driving signal (OUT1P) and a second output branch (404) having a second differential input terminal (I1N) operatively connected to the second differential output terminal (O1N) of the output stage (401) to receive the second differential driving signal (Out1N), —a control circuit (405) configured to control the output stage (402).

Abstract: The invention relates to a two-stage operational amplifier (400) in class AB for driving a load (RLB, RLA) comprising: an input stage (401) comprising differential input terminals (IN, lp) and a first differential output terminal (O1P) and a second differential output terminal (O1N) for providing a first differential driving signal (Out1P) and a second differential driving signal (Out1N), respectively; an output stage (402) comprising a first output branch (403) having a first differential input terminal (I1P) operatively connected to the first differential output terminal (O1P) of the input stage (401) to receive the first differential driving signal (OUT1P) and a second output branch (404) having a second differential input terminal (I1N) operatively connected to the second differential output terminal (O1N) of the output stage (401) to receive the second differential driving signal (Out1N), a control circuit (405) configured to control the output stage (402).

Abstract: A low-noise reference voltages distribution circuit (10) is disclosed, comprising a multi-output voltage to current converter (V/I_Conv) adapted to receive an input reference voltage (VR) for providing a plurality of output reference currents (I1, . . . , IN) to be converted into a plurality of local reference voltages (V01, V0N) at corresponding receiving circuits (LCR1, LCRN) adapted to be connected to said reference voltages distribution circuit (10). The multi-output voltage to current converter (V/I_Conv) comprises: -an input section (20) adapted to generate on the basis of said input reference voltage (VR) a reference current (I0), the input section (20) comprising a current mirror input transistor (M0E) having a voltage controlled input terminal (g0E); -an output section (50) comprising a plurality of current mirror output transistors (M01, M0N) each adapted to provide a corresponding output reference current of said plurality of reference currents (I1, . . .

Abstract: A microphone preamplifier circuit (60) is described, adapted to be connected to a microphone circuit (MCD), the microphone circuit (MCD) comprising a microphone (3) and at least one output node (MO, MO?).

Abstract: An interface circuit is provided that is adapted to connect a microphone circuit to a preamplifier. The microphone circuit has a microphone and at least an output node and the preamplifier has at least an input node connected to the output node by the interface circuit. The interface circuit has at least a decoupling capacitor for DC decoupling the input node from the output node. The decoupling is connected between the input node and the output node. The interface circuit has at least one active circuit, comprising a resistor connected the decoupling capacitor. The resistor acts as part of a resistance multiplier and has an equivalent resistance that together with the decoupling capacitor defines a high-pass filter connected between the microphone and the preamplifier. The interface circuit may also have a biasing circuit connected to the resistor.

Abstract: An operational amplifier having a first amplification stage with an input terminal to receive a signal to be amplified, and a first output terminal, and a second amplification stage having a first input terminal connected to the first output terminal, and an output terminal to provide the amplified signal. The first and second amplification stages define, between the input terminal and the output terminal, a signal transfer function having first and second poles. The amplifier further includes a decoupling stage having a further input terminal connected to the first stage input terminal, and a further output terminal connected to the second stage output terminal. The decoupling stage is so arranged as to introduce at least one zero in the operational amplifier transfer function.

Abstract: A voltage following device is described, for the driving of a sampling network coupleable to an analog/digital converter, comprising at least one first transistor provided with a first terminal to receive an input signal, and a second terminal to provide an output signal to the sampling network which is representative of the input signal translation of an amount equal to a gate and source voltage of said at least one first transistor. The voltage following device having a driving network of said at least one first transistor to keep said gate and source voltage equal to a shift reference voltage.

Abstract: An operational amplifier having a first amplification stage with an input terminal to receive a signal to be amplified, and a first output terminal, and a second amplification stage having a first input terminal connected to the first output terminal, and an output terminal to provide the amplified signal. The first and second amplification stages define, between the input terminal and the output terminal, a signal transfer function having first and second poles. The amplifier further includes a decoupling stage having a further input terminal connected to the first stage input terminal, and a further output terminal connected to the second stage output terminal. The decoupling stage is so arranged as to introduce at least one zero in the operational amplifier transfer function.