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 single-ended to differential buffer circuit is is disclosed, adapted to couple at least an input analog signal to a receiving circuit. The buffer circuit comprises an output section comprising a differential amplifier having a first and a second input, a first and a second output. The buffer circuit further comprises an input section comprising a first and a second switched capacitor, each adapted to sample said input analog signal and having a first side and a second side, the first sides of the first and second switched capacitors being controllably connectable/disconnectable to/from said first and second outputs respectively. In the buffer circuit the second sides of said first and second switched capacitors are controllably connectable/disconnectable to/from said first and second inputs of the differential amplifier respectively.

Abstract: The invention relates to an electronic integrated amplifier for driving an acoustic transducer. The amplifier comprises two differential input terminals to receive an input signal and a first and a second output terminal to provide an output signal to the transducer. In addition, the amplifier comprises an operational amplifier having an input end including differential inputs and an output end operatively associated with the first and second output terminals. A pair of input resistors connect the two differential input terminals to two intermediate terminals, respectively. A pair of feedback resistors connect the first and second output terminals to the two intermediate terminals, respectively. The integrated amplifier also comprises means for high-pass filtering the input signal.

Abstract: An integrated programmable gain amplifier circuit that receives at an input an analog signal, circuit including an operational amplifier and a gain setup network comprising resistive elements and selection elements, which may be controlled in order to setup the gain of the amplifier circuit. The gain setup network further includes capacitive elements, for defining, together with the resistive elements and the operational amplifier, an anti-aliasing filter of the active RC type.

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 calibration circuit for calibrating an adjustable capacitance of a circuit having a time constant depending on the adjustable capacitance, the calibration circuit generating a calibration signal for calibrating the capacitance and including a calibration loop, suitable to carry out a calibration cycle in several sequential steps.

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: The present disclosure relates to an electronic regulation device of a variable capacitance of an integrated circuit having a time parameter depending on the variable capacitance. The regulation device includes a regulation loop, and is configured to generate in output a plurality of binary regulation signals.

Abstract: An electric circuit includes a supply terminal to receive an outer supply voltage and a voltage regulator coupled to the supply terminal and to provide supply and resting voltages. A lock-out circuit is switchable between active and inactive states and receives the supply voltage at a supply node to generate, in the active state, an output voltage on a output terminal thereof. A protection circuit protects against electrostatic discharge, having at least one first diode coupled between the supply node and the output terminal. A cut-off electronic lock couples, in the inactive state, the supply node to the supply terminal by reverse biasing the at least one first diode to make a voltage of the output terminal float.

Abstract: An integrated buffer device for a switched capacitance circuit having a buffer with an output for an output voltage dependent upon an input voltage that can be supplied by a source to the buffer device; a capacitive switching component that can be switched between a first and second condition and connected, respectively, to the source and to the buffer to transfer the input voltage onto the output; the capacitive switching component provided with a terminal having an associated stray capacitance; a charging and discharging device configured to pre-charge the stray capacitance at a reference voltage before taking up the second condition and to pre-discharge the stray capacitance before taking up the first condition.

Abstract: An integrated programmable gain amplifier circuit that receives at an input an analog signal, circuit including an operational amplifier and a gain setup network comprising resistive elements and selection elements, which may be controlled in order to setup the gain of the amplifier circuit. The gain setup network further includes capacitive elements, for defining, together with the resistive elements and the operational amplifier, an anti-aliasing filter of the active RC type.

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: An analog-to-digital conversion circuit and device having an input stage arranged to receive an input signal and to provide an output analog signal as a function of the input signal; an analog-to-digital conversion block arranged to receive the output analog signal and to provide a respective output digital signal. The input stage includes a first voltage buffer arranged to provide the output analog signal to the conversion block as the translation of the input signal of an amount equal to a translation voltage; a second voltage buffer arranged to provide a first reference signal to the conversion block that is representative of the translation of a first reference voltage of an amount equal to the translation voltage, so that the conversion block stores the input signal as the difference of the input signal and the first reference voltage regardless of the translation voltage.

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 integrated buffer device for a switched capacitance circuit having a buffer with an output for an output voltage dependent upon an input voltage that can be supplied by a source to the buffer device; a capacitive switching component that can be switched between a first and second condition and connected, respectively, to the source and to the buffer to transfer the input voltage onto the output; the capacitive switching component provided with a terminal having an associated stray capacitance; a charging and discharging device configured to pre-charge the stray capacitance at a reference voltage before taking up the second condition and to pre-discharge the stray capacitance before taking up the first condition.

Abstract: A device comprising: an input for an electric signal; an integrator stage connected to said input to provide an integrated signal; an amplifier stage electrically coupled to the integrator stage to receive said integrated signal and to provide an output signal. The device being characterized in that the integrator stage is such that the integrated signal is obtained by an individual signal integration operation.

Abstract: A calibration circuit for calibrating an adjustable capacitance of a circuit having a time constant depending on the adjustable capacitance, the calibration circuit generating a calibration signal for calibrating the capacitance and including a calibration loop, suitable to carry out a calibration cycle in several sequential steps.

Abstract: A circuit for reconstructing an analog signal starting from a digital input signal includes a digital to analog converter and a low pass-filter connected at the output of the converter for receiving the analog format signal and outputting a reconstructed analog signal. The low pass filter is an active filter continuous in time and current-coupled to the output of the digital-analog converter. The digital-analog converter is of the current-steering type functioning at a sampling frequency greater than the Nyquist frequency of the analog signal.

Abstract: An electric circuit includes a supply terminal to receive an outer supply voltage and a voltage regulator coupled to the supply terminal and to provide supply and resting voltages. A lock-out circuit is switchable between active and inactive states and receives the supply voltage at a supply node to generate, in the active state, an output voltage on a output terminal thereof. A protection circuit protects against electrostatic discharge, having at least one first diode coupled between the supply node and the output terminal. A cut-off electronic lock couples, in the inactive state, the supply node to the supply terminal by reverse biasing the at least one first diode to make a voltage of the output terminal float.

Abstract: A digital-to-analog converter includes a first section (MSB) that converts the more significant bits of a digital code into a first voltage (Vin) of a multiplicity of discrete voltages that are integral multiples of a predetermined first voltage step (?V1). A second section (LSB) of the converter converts the less significant bits of the digital code into a current. The current is transformed into a second voltage of a multiplicity of discrete voltages that are integral multiples of a second voltage step (?V2) equal to ½ L of the product of the first voltage step (?V1) multiplied by a predetermined coefficient, where L is the number of the less significant bits of the digital code to be converted. A summer generates an output voltage (Vout) that is the sum of the second voltage and the product of the first voltage multiplied by the predetermined coefficient. With a view to obtaining a low consumption, the summer has a resistive feedback circuit including a voltage divider (R3, R4).