An amplifier circuit includes a multistage amplifier, a first feedback circuit and a second feedback circuit. The multistage amplifier includes a first-staged amplifier, a last-staged amplifier and at least one middle-staged amplifier cascaded between the first-staged amplifier and the last-staged amplifier. The first feedback circuit is configured to couple a positive output end of the last-staged amplifier to a positive input end of the at least one middle-staged amplifier, or is configured to couple a negative output end of the last-staged amplifier to a negative input end of the at least one middle-staged amplifier. The second feedback circuit is configured to couple the positive output end of the last-staged amplifier to a positive input end of the last-staged amplifier, or is configured to couple the negative output end of the last-staged amplifier to a negative input end of the last-staged amplifier.

An amplifier circuit includes a multistage amplifier, a first feedback circuit and a second feedback circuit. The multistage amplifier includes a first-staged amplifier, a last-staged amplifier and at least one middle-staged amplifier cascaded between the first-staged amplifier and the last-staged amplifier. The first feedback circuit is configured to couple a positive output end of the last-staged amplifier to a positive input end of the at least one middle-staged amplifier, or is configured to couple a negative output end of the last-staged amplifier to a negative input end of the at least one middle-staged amplifier. The second feedback circuit is configured to couple the positive output end of the last-staged amplifier to a positive input end of the last-staged amplifier, or is configured to couple the negative output end of the last-staged amplifier to a negative input end of the last-staged amplifier.

An amplifier circuit includes a multistage amplifier, a first feedback circuit and a second feedback circuit. The multistage amplifier includes a first-staged amplifier, a last-staged amplifier and at least one middle-staged amplifier cascaded between the first-staged amplifier and the last-staged amplifier. The first feedback circuit is configured to couple a positive output end of the last-staged amplifier to a positive input end of the at least one middle-staged amplifier, or is configured to couple a negative output end of the last-staged amplifier to a negative input end of the at least one middle-staged amplifier. The second feedback circuit is configured to couple the positive output end of the last-staged amplifier to a positive input end of the last-staged amplifier, or is configured to couple the negative output end of the last-staged amplifier to a negative input end of the last-staged amplifier.

An amplifier circuit includes a multistage amplifier, a first feedback circuit and a second feedback circuit. The multistage amplifier includes a first-staged amplifier, a last-staged amplifier and at least one middle-staged amplifier cascaded between the first-staged amplifier and the last-staged amplifier. The first feedback circuit is configured to couple a positive output end of the last-staged amplifier to a positive input end of the at least one middle-staged amplifier, or is configured to couple a negative output end of the last-staged amplifier to a negative input end of the at least one middle-staged amplifier. The second feedback circuit is configured to couple the positive output end of the last-staged amplifier to a positive input end of the last-staged amplifier, or is configured to couple the negative output end of the last-staged amplifier to a negative input end of the last-staged amplifier.

A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a first sense resistor coupled between the first high-side switch and the supply voltage, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the first sense resistor when the first high-side switch is activated. The current sensing circuitry may also include a second sense resistor coupled between the second high-side switch and the supply voltage, such that an output current through the load causes a second sense voltage proportional to the output current across the second sense resistor when the second high-side switch is activated. The system may also include measurement circuitry configured to measure the first sense voltage and the second sense voltage to determine the output current.

A system may include a Class-D stage comprising a first high-side switch coupled between a supply voltage and a first output terminal of the Class-D stage, a second high-side switch coupled between the supply voltage and a second output terminal of the Class-D stage, a first low-side switch coupled between a ground voltage and the first output terminal, and a second low-side switch coupled between the ground voltage and the second output terminal. The system may also include current sensing circuitry comprising a first sense resistor coupled between the first high-side switch and the supply voltage, such that an output current through a load coupled between the first output terminal and the second output terminal causes a first sense voltage proportional to the output current across the first sense resistor when the first high-side switch is activated. The current sensing circuitry may also include a second sense resistor coupled between the second high-side switch and the supply voltage, such that an output current through the load causes a second sense voltage proportional to the output current across the second sense resistor when the second high-side switch is activated. The system may also include measurement circuitry configured to measure the first sense voltage and the second sense voltage to determine the output current.

Reducing a sensitivity of an electromechanical sensor is presented herein. The electromechanical sensor comprises a sensitivity with respect to a variation of a mechanical-to-electrical gain of a sense element of the electromechanical sensor; and a voltage-to-voltage converter component that minimizes the sensitivity by coupling, via a defined feedback capacitance, a positive feedback voltage to a sense electrode of the sense element—the sense element electrically coupled to an input of the voltage-to-voltage converter component. In one example, the voltage-to-voltage converter component minimizes the sensitivity by maintaining, via the defined feedback capacitance, a constant charge at the sense electrode. In another example, the electromechanical sensor comprises a capacitive sense element comprising a first node comprising the sense electrode. Further, a bias voltage component can apply a bias voltage to a second node of the electromechanical sensor. In yet another example, the electromechanical sensor comprises a piezoelectric sense element.

A radiofrequency transmission/reception integrated circuit includes at least one radiofrequency signal amplifier (PA, LNA), the at least one amplifier being configured, in operational mode, so as to perform a function of amplifying a radiofrequency signal applied at input, wherein the amplifier is configured so as to perform an oscillator function in a self-test mode of the integrated circuit, to generate a radiofrequency signal on at least one of the input or the output of said amplifier. A self-test method for such an integrated circuit is also provided.

A resonant tank includes a first capacitor formed on a semiconductor substrate, a first inductor formed on the semiconductor substrate, a second capacitor formed on the semiconductor substrate, and a second inductor formed on the semiconductor substrate. The first capacitor, the first inductor, the second capacitor, and the second inductor are connected in a ring configuration, with each capacitor connected between a pair of the inductors and with each inductor connected between a pair of the capacitors. An amplifier circuit is coupled to the resonant tank and configured to amplify a signal in the resonant tank.

A resonant tank includes a first capacitor formed on a semiconductor substrate, a first inductor formed on the semiconductor substrate, a second capacitor formed on the semiconductor substrate, and a second inductor formed on the semiconductor substrate. The first capacitor, the first inductor, the second capacitor, and the second inductor are connected in a ring configuration, with each capacitor connected between a pair of the inductors and with each inductor connected between a pair of the capacitors. An amplifier circuit is coupled to the resonant tank and configured to amplify a signal in the resonant tank.