A sigma-delta ADC comprising: a first-input-terminal configured to receive a first-high-voltage-analogue-input-signal; a second-input-terminal configured to receive a second-high-voltage-analogue-input-signal; an output-terminal configured to provide an output-digital-signal, wherein the output-digital-signal is representative of the difference between the first-high-voltage-analogue-input-signal and the second-high-voltage-analogue-input-signal. The sigma-delta ADC also includes a feedback-current-block, which comprises: a first-feedback-transistor having a conduction channel; a second-feedback-transistor having a conduction channel; a first-feedback-switch; a second-feedback-switch; a first-feedback-current-source; and a second-feedback-current-source.

A read-out circuitry for acquiring a multi-channel biopotential signal, comprises: a plurality of read-out signal channels, each receiving an input signal from a unique signal electrode; a reference channel receiving a reference signal from a reference electrode; wherein each read-out signal channel and the reference channel comprises a channel amplifier connected to receive the input signal in a first input node and with an output node connected to a second input node via a channel feedback loop; wherein each signal channel amplifier comprises a capacitor between the second input nodes of the signal channel amplifier and the reference channel amplifier, and wherein each signal channel feedback loop and the reference channel feedback loop comprise a filter.

An example log power detector includes a gain or attenuation circuit and a detector circuit. The gain or attenuation circuit includes a plurality of gain or attenuation elements arranged in a sequence, each gain or attenuation element configured to generate an output signal that is an amplified or attenuated version of an input signal provided thereto. The detector circuit includes a plurality of detectors, each detector configured to receive the output signal from a different one of the gain or attenuation elements and to generate a signal indicative of a power of the received output signal. At least the last detector is configured to receive a DC offset signal that is different from a DC offset signal received by at least one other detector. Such a log detector may provide effective noise compensation to reduce errors caused by input noise, especially for low-power and/or high-frequency input signals.

A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression.

The present application discloses an amplifier and a method for controlling a common mode voltage thereof. The method includes: generating a control signal according to a positive-terminal input signal, a negative-terminal input signal and a target common mode voltage; and coupling the controlling signal to a first terminal of a positive-terminal capacitor and a first terminal of a negative-terminal capacitor, to adjust degree of conduction of a positive-terminal p-type transistor and degree of conduction of a negative-terminal p-type transistor, or to adjust degree of conduction of a positive-terminal n-type transistor and degree of conduction of a negative-terminal n-type transistor, thereby changing a common mode voltage.

A signal processing assembly for a detector includes a signal amplifier, a control unit, and an offset control module. The signal amplifier is configured to receive an input signal from the detector assembly and to provide an output signal. The control unit is configured to compare a first data point from the output signal with a signal range, and to generate an input bias control signal based upon the comparison. The offset control module is coupled with the control unit and configured to receive the input bias control signal. The offset control module includes a power supply operatively coupled with an input of the signal amplifier, and the offset control module is configured to generate and apply an adaptive input offset signal at the input of the signal amplifier based upon the input bias control signal.

A system, disposed within a wearable hearing device, includes a sound producing device (SPD) driven by a driving voltage, a first sound sensing device, and a subtraction circuit. The first sound sensing device is configured to sense a combined sound pressure produced at least by the SPD and generate a sensed signal accordingly. The subtraction circuit has a first input terminal, a second input terminal, and a first output terminal. The first input terminal is coupled to the first sound sensing device, and the first output terminal is coupled to the SPD. A first phase delay between the driving voltage and the sensed signal is less than 60°.

A signal processing assembly for a detector includes a signal amplifier, a control unit, and an offset control module. The signal amplifier is configured to receive an input signal from the detector assembly and to provide an output signal. The control unit is configured to compare a first data point from the output signal with a signal range, and to generate an input bias control signal based upon the comparison. The offset control module is coupled with the control unit and configured to receive the input bias control signal. The offset control module includes a power supply operatively coupled with an input of the signal amplifier, and the offset control module is configured to generate and apply an adaptive input offset signal at the input of the signal amplifier based upon the input bias control signal.

A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression.

The present invention provides a circuit including a reference voltage generator and a plurality of receivers, wherein the reference voltage generator is configured to generate a reference voltage, and each of the receivers is configured to receive the reference voltage and a corresponding input signal to generate a corresponding output signal. In addition, for at least a specific receiver of the plurality of receivers, the specific receiver comprises at least one amplifying stage, the amplifying stage comprises a first input terminal configured to receive the corresponding input signal, a second input terminal configured to receive the reference voltage, a first output terminal configured to generate a first signal, and a second output terminal configured to generate a second signal; and the specific receiver further comprises a first feedback circuit coupled between the first output terminal and the second input terminal.