An electronic amplification-interface circuit includes a differential-current reading circuit having a first input terminal and a second input terminal. The differential-current reading circuit includes a continuous-time sigma-delta conversion circuit formed by an integrator-and-adder module generating an output signal that is coupled to an input of a multilevel-quantizer circuit configured to output a multilevel quantized signal. The integrator-and-adder module includes a differential current-integrator circuit configured to output a voltage proportional to an integral of a difference between currents received at the first and second input terminals. A digital-to-analog converter, driven by a respective reference current, receives and converts the multilevel quantized signal into a differential analog feedback signal. The integrator-and-adder module adds the differential analog feedback signal to the differential signal formed at the first and second input terminals.

An electronic amplification-interface circuit includes a differential-current reading circuit having a first input terminal and a second input terminal. The differential-current reading circuit includes a continuous-time sigma-delta conversion circuit formed by an integrator-and-adder module generating an output signal that is coupled to an input of a multilevel-quantizer circuit configured to output a multilevel quantized signal. The integrator-and-adder module includes a differential current-integrator circuit configured to output a voltage proportional to an integral of a difference between currents received at the first and second input terminals. A digital-to-analog converter, driven by a respective reference current, receives and converts the multilevel quantized signal into a differential analog feedback signal. The integrator-and-adder module adds the differential analog feedback signal to the differential signal formed at the first and second input terminals.

An analog discrete current mode negative feedback amplifier circuit for use with a micro-fused strain gauge is disclosed. The amplifier circuit includes a Wheatstone bridge coupled to a first power supply and a second power supply. The first power supply and the second power supply can be configured such that the periodically alternate between two voltage levels. The Wheatstone bridge can be coupled to a negative feedback amplifier circuit with common mode detection. The amplifier circuit can comprise a differential amplifier with a negative feedback configuration coupled to a common mode amplifier. In addition, the output of each of the amplifiers can be coupled to a common-mode amplifier. In a pressure sensing application, the output of the common mode amplifier serves to output the temperature while the differential amplifiers serve to output the pressure.

An analog discrete current mode negative feedback amplifier circuit for use with a micro-fused strain gauge is disclosed. The amplifier circuit includes a Wheatstone bridge coupled to a first power supply and a second power supply. The first power supply and the second power supply can be configured such that the periodically alternate between two voltage levels. The Wheatstone bridge can be coupled to a negative feedback amplifier circuit with common mode detection. The amplifier circuit can comprise a differential amplifier with a negative feedback configuration coupled to a common mode amplifier. In addition, the output of each of the amplifiers can be coupled to a common-mode amplifier. In a pressure sensing application, the output of the common mode amplifier serves to output the temperature while the differential amplifiers serve to output the pressure.

A class-D amplifier includes a loop filter, a pulse-width modulation (PWM) circuit, an output circuit, and a common-mode control circuit. The loop filter receives an input signal of the class-D amplifier to generate a filtered signal. The PWM circuit converts a non-PWM signal into a PWM signal, wherein the non-PWM signal is derived from at least the filtered signal. The output circuit generates an output signal of the class-D amplifier according to the PWM signal. The common-mode control circuit monitors a common-mode level of the output signal to generate a common-mode control signal for PWM common-mode control.

A class-D amplifier includes a loop filter, a pulse-width modulation (PWM) circuit, an output circuit, and a common-mode control circuit. The loop filter receives an input signal of the class-D amplifier to generate a filtered signal. The PWM circuit converts a non-PWM signal into a PWM signal, wherein the non-PWM signal is derived from at least the filtered signal. The output circuit generates an output signal of the class-D amplifier according to the PWM signal. The common-mode control circuit monitors a common-mode level of the output signal to generate a common-mode control signal for PWM common-mode control.

The present disclosure provides a neuromodulation device that comprises at least one amplifier circuit that suppresses a common mode (CM) voltage signal in the input voltage signal. The amplifier circuit comprises an input stage to receive the input voltage signal, and a differential transconductor to provide an output current signal based on a DM voltage signal in the input voltage signal. The transconductor is provides a first CM voltage signal tapped after a non-inverting input, and a second CM voltage signal tapped after am inverting input, to CM amplifier of the amplifier circuit. The CM amplifier combines the first CM voltage signal with the second CM voltage signal, amplifies the combined CM voltage signal with an inverting gain, and provides the inverted CM voltage signal back to the non-inverting input and the inverting input of the transconductor for enabling the CM suppression.

A method of audio signal processing includes receiving a first audio input signal (first input signal) at an input of a first integrating amplifier of a first single-ended (SE) closed loop channel, and second input signal with a polarity reversed relative to the first input signal at an input of a second integrating amplifier configured of a second SE closed loop channel. During audio signal processing a common-mode (CM) reference voltage level applied to a current source coupled to an input of the first and second integrating amplifiers is dynamically changed including whenever a level of the input signals is below a predetermined low level, reducing the CM reference voltage level for implementing low duty cycle (LDC) PWM operation, and whenever the level is above a level that corresponds to an onset of clipping, increasing the CM reference voltage level for at least reducing the clipping to lower crossover distortion.

A transconductance-transimpedance (TAS-TIA) amplifier includes a TAS amplifier, a TIA amplifier, and a first common-mode feedback (CMFB) circuit. The TIA amplifier includes a first transistor and a second transistor. The first transistor is coupled between a first TIA output node and a reference voltage. The second transistor is coupled between a second TIA output node and the reference voltage. The first CMFB circuit has a first operational amplifier, a first capacitor, and a first resistor. The first operational amplifier has a first input node for receiving a TIA output common-mode voltage, a second input node, and a first output node coupled to control terminals of the first and second transistors. The first capacitor is coupled between the first output node and the second input node of the first operational amplifier. The first resistor is coupled between the second input node of the first operational amplifier and a reference common-mode voltage.