The present invention provides an amplifier circuit, wherein the amplifier circuit includes an input terminal, a capacitor, an amplifier, a feedback circuit and an aliasing tone cancellation circuit. The input terminal is configured to receive a first input signal. The capacitor is coupled to the input terminal. The amplifier is configured to receive the input signal through the capacitor to generate an output signal. The feedback circuit is coupled between an input node and an output node of the amplifier, and is configured to generate a feedback signal according to the output signal, wherein the feedback circuit includes a storage block including a switched-capacitor. The aliasing tone cancellation circuit is coupled between the input terminal of the amplifier circuit and the input node of the amplifier, and configured to generate a signal to cancel or reduce an aliasing tone of the feedback signal according to the input signal.

A differential to single-ended buffer amplifier with a swing suppression resistor in the differential amplification architecture is shown. The differential to single-ended buffer amplifier has a positive input terminal, a negative input terminal, a differential to single-ended operational amplifier (DISO op amp), and a swing suppression resistor. The DISO op amp has a non-inverting input terminal and an inverting input terminal respectively coupled to the positive input terminal and the negative input terminal, and it has a single-ended output terminal that outputs the output signal of the differential to single-ended buffer amplifier. The swing suppression resistor is connected between the negative input terminal of the differential to single-ended buffer amplifier and the non-inverting input terminal of the DISO op amp.

The present application discloses an amplifier circuit, a chip and an electronic device, which generates a positive output signal and a negative output signal according to a positive input signal and a negative input signal, wherein the positive input signal and the negative input signal have a corresponding input differential-mode voltage and input common-mode voltage, and the positive output signal and the negative output signal have a corresponding output differential-mode voltage and output common-mode voltage, and the amplifier circuit includes: an amplifying unit, configured to receive the positive input signal and the negative input signal and generate the positive output signal and the negative output signal; and an attenuation unit, including: a positive common-mode capacitor and a negative common-mode capacitor, configured to attenuate the input common-mode voltage below a first specific frequency.

A method and system of compensating for component mismatch are disclosed. An example system comprises an amplifier including a current ratio measurement engine (CRME) and a modulator (DSM). The CRME is configured to obtain measurements for each possible configuration of an amplifier circuit and to pass these measurements to a processor for analysis. In the example system, the measurements are obtained by driving a bias current through two or more circuit elements and measuring the ratio in current between the two or more circuit elements, which is representative of the relative mismatch between the two or more components. The DSM is configured to receive adjustment parameters from the processor and to tune the amplifier circuit according to the adjustment parameters to thereby improve the performance of the amplifier.

This application relates to driver circuitry (200) for receiving a digital input signal (D) and outputting, at first and second output nodes (203p, 203n), first and second analogue driving signals respectively for driving a transducer (101), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters (201p, 201n) configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit (202) has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.

An operational amplifier includes a single-stage amplifier and a current controller. The single-stage amplifier receives an input signal, and amplifies the input signal to generate an output signal, wherein the single-stage amplifier includes a voltage controlled current source circuit that operates in response to a bias voltage input. The current controller receives the input signal, and generates the bias voltage input according to the input signal. The bias voltage input includes a first bias voltage, a second bias voltage, a third bias voltage, and a fourth bias voltage. None of the first bias voltage, the second bias voltage, the third bias voltage, and the fourth bias voltage is directly set by the input signal of the single-stage amplifier.

The present invention provides a circuit applied to a biopotential acquisition system, wherein the circuit includes an active current source and an amplifier. In the operations of the circuit, the active current source is configured to provide a current to two input terminals of the circuit, wherein the two input terminals of the circuit are coupled to two input electrodes of the biopotential acquisition system; and the amplifier is configured to receive input signals from the two input terminals to generate an output signal.

A differential amplifier comprises: a long tailed pair transistor configuration comprising a differential pair of transistors and a tail transistor; and a replica circuit configured to vary a feedback current in the replica circuit to match a replica voltage to a reference voltage, wherein varying the feedback current in the replica circuit 4 provides a bias voltage to the tail transistor in the long tailed pair which controls a tail current through the tail transistor to determine a common mode voltage in the long tailed pair.

Various embodiments of the invention provide for an AC-coupling method and systems that utilize a nested loop circuit to generate a differential mode output that facilitates an offset compensation and a common mode output that facilitates DC-biasing of an active circuit. In embodiments, the nested loop circuit comprises a differential amplifier and a differential mode loop that generates a differential mode output and a common mode loop that uses a common mode voltage and a reference voltage to generate the common mode output.

A semiconductor device includes a differential amplification circuit that outputs differential output signals Vo1 and Vo2, external output terminals PD1 and PD2 to which one of the differential output signals Vo1 and Vo2 and single end signals Vo3 and Vo4 is selectively supplied, switch units SW1 and SW2 that control a conduction state between the external output terminal PD1 and the feedback line and a conduction state between the external output terminal PD2 and the feedback line, respectively, resistance elements R1 and R2 respectively provided in series with the switch units SW1 and SW2, a CMFB circuit that controls a common mode voltage of the differential amplification circuit according to a difference between an intermediate voltage Vcm of the external output terminals PD1 and PD2 in the feedback line and a reference voltage Vref, and a switch unit SW3 that controls to supply a clamp voltage to the feedback line.