Stmicroelectronics S.r.l.

St-Ericsson Sa

Politecnico Di Milano

Optis Circuit Technology, LLC

Stmicroelectron S.r.l.

Andrea Barbieri

Germano Nicollini

Sergio Pernici

Marco Zamprogno

Aldo Vidoni

Luca Molinari

Edoardo Marino

Federica Barbieri

Roberto Carminati

Sebastiano Conti

Giuseppe Maiocchi

Giacomo Langfelder

Silvia Adorno

Nicolo' Boni

Alberto Danioni

Pasquale Flora

Franco Consiglieri

Raffaele Enrico Furceri

Paolo Frigerio

Nicolò Boni

A DC-DC boost converter includes an inductor coupled between an input voltage and an input node, a first path coupled between the input node and a first output node at which a first output voltage is generated, and a second path coupled between the input node and a second output node at which a second output voltage is generated. The DC-DC boost converter operates in a first operating phase where the first path boosts the first output voltage and where the second path is kept from boosting the second output voltage by the second path being coupled to the first path, and operates in a second operating phase where the second path boosts the second output voltage and where the first path is kept from boosting the first output voltage by the second path not being coupled to the first path.

Dual output DC-DC boost converter with reduced output leakage

A MEMS device includes a semiconductor body with a cavity and forming an anchor portion, a tiltable structure elastically suspended over the cavity, first and second support arms to support the tiltable structure, and first and second piezoelectric actuation structures biasable to deform mechanically, generating a rotation of the tiltable structure around a rotation axis. The piezoelectric actuation structures carry first and second piezoelectric displacement sensors. When the tiltable structure rotates around the rotation axis, the displacement sensors are subject to respective mechanical deformations and generate respective sensing signals in phase opposition to each other, indicative of the rotation of the tiltable structure. The sensing signals are configured to be acquired in a differential manner.

MEMS device with tiltable structure and improved control

A DC-DC boost converter includes an inductor coupled between an input voltage and an input node, a diode coupled between the input node and an output node, and an output capacitor coupled between the output node and ground such that an output voltage is formed across the output capacitor. A switch selectively couples the input node to ground in response to a drive signal. Control loop circuitry includes an error amplifier to generate an analog error voltage based upon a comparison of a feedback voltage to a reference voltage, the feedback voltage being indicative of the output voltage, a quantizer to quantize the analog error voltage to produce a digital error signal, and a drive voltage generation circuit to generate the drive signal as having a duty cycle based upon the digital error signal.

Control loop and efficiency enhancement for DC-DC converters

Disclosed herein is a control system for a projection system, including a first subtractor receiving an input drive signal and a feedback signal and generating a first difference signal therefrom, the feedback signal being indicative of position of a quasi static micromirror of the projection system. A type-2 compensator receives the first difference signal and generates therefrom a first output signal. A derivative based controller receives the feedback signal and generates therefrom a second output signal. A second subtractor receives the first and second output signals and generates a second difference signal therefrom. The second difference signal serves to control a mirror driver of the projection system. A higher order resonance equalization circuit receives a pre-output signal from an analog front end of the projection system that is indicative of position of the quasi static micromirror, and generates the feedback signal therefrom.

Closed-loop position control of MEMS micromirrors

A negative impedance circuit includes: a differential circuit stage; a positive feedback path from an output of the differential circuit stage to a first input of the differential circuit stage; and a negative feedback path from the output of the differential circuit stage to a second input of the differential circuit stage. The negative feedback path includes a first transistor, and a unitary gain path from the output of the differential circuit stage to the second input of the differential circuit stage, the unitary gain path coupled to ground via a reference impedance. The positive feedback path includes a second transistor. The first and second transistors are coupled in a current mirror arrangement and have respective control electrodes configured to be driven by the output of the differential circuit stage, where the negative impedance circuit causes a negative impedance at the first input of the differential circuit stage.

Negative impedance circuit and corresponding device

A bridge driver circuit applies a bias voltage across first and second input nodes of a resistive bridge circuit configured to measure a physical property such as pressure or movement. A sensing circuit senses drive current, bias current and common mode current for the bridge driver and sums the sensed currents to generate a source current. The source current is processed to determine a normalized resistance and temperature of the resistive bridge circuit and from which a temperature dependent sensitivity of the resistive bridge circuit is determined. A voltage output at first and second output nodes of the resistive bridge circuit is processed to determine a value of the physical property. This processing further involves applying a temperature correction in response to the determined temperature dependent sensitivity.

Resistive bridge sensor with temperature compensation

A fully balanced differential difference amplifier includes a first differential input stage that receives an input voltage and a second differential input stage that receives a common-mode voltage. A first resistive-degeneration group is coupled to the first differential input and a second resistive-degeneration group is coupled to the second differential input. A differential output stage generates an output voltage. A first switch is coupled in parallel to the first resistive-degeneration group and a second switch is coupled in parallel with 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.

FBDDA amplifier and device including the FBDDA amplifier

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 amplifier, which is coupled at input to the second input terminal and defines a first differential output of the circuit; a second 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.

Differential amplifier circuit for a capacitive acoustic transducer and corresponding capacitive acoustic transducer

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. The detection structure has a first micromechanical structure of a capacitive type and a second micromechanical structure of a capacitive type, each including a membrane that faces and is capacitively coupled to a rigid electrode and defines a respective first detection capacitor and second detection capacitor; the electronic interface circuit defines an electrical connection in series of the first detection capacitor and second detection capacitor between a biasing line and a reference line, and further has a first single-output amplifier and a second single-output amplifier, which are coupled to a respective one of the first detection capacitor and the second detection capacitor and have a respective first output terminal and second output terminal, between which the electrical output quantity is present.

Differential-type MEMS acoustic transducer

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.

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.

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. The microphone preamplifier circuit further includes an anti-aliasing filter having: (i) at least one output terminal connected to the at least one input DC decoupling capacitor and (ii) at least one input terminal adapted to be connected to the at least one output node of the microphone circuit.

Microphone preamplifier circuit

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.

Biasing circuit for a MEMS acoustic transducer with reduced start-up time

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.

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Casalpusterlengo, Italy

Andrea Barbieri