A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

An analog-to-digital conversion circuit includes: a variable gain amplifier; a delta-sigma modulator that modulates an output of the variable gain amplifier to a pulse density modulation (PDM) signal; and a decimation filter that downsamples the PDM signal to output a first digital signal that is converted into a multi-bit digital signal. The decimation filter includes: a weight change unit that converts the PDM signal into a second digital signal that is weighted by multiplying a weight of the PDM signal by a reciprocal of an amplification factor of the variable gain amplifier; and a first digital filter that receives the second digital signal as an input, and outputs the first digital signal.

A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

A signal processor and a method for processing an input signal are presented. The signal processor is adapted to clip an oversampled input signal without introducing noise in the frequency band of interest. For instance, the signal processor may be used for clipping an acoustic signal. The signal processor includes a summer coupled to a limiter and to a feedback circuit. The summer is adapted to sum the input signal with at least one feedback signal to provide an adjusted signal. The limiter is adapted to compare the adjusted signal with a first threshold value and a second threshold value to provide a limited signal. The feedback circuit is adapted to calculate a difference between the limited signal and the adjusted signal, and to generate at least one feedback signal based on the difference.

A microphone assembly includes a transducer element and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize a microphone signal generated by the transducer element to generate a corresponding digital microphone signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital microphone signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node at the transducer output configured to combine the microphone signal and the analog feedback signal.

A method includes applying a current to an input pin of an integrated circuit; converting an analog signal at the input pin to a digital stream using a Sigma-Delta modulator; converting the digital stream to a first digital output signal proportional to the analog signal in a first input range between a first analog signal value and a second analog signal value, where the first input range corresponds to a pre-determined range of the analog signal smaller than a full-scale input range of the analog signal; converting the digital stream to a second output signal; comparing the second output signal to a first threshold corresponding to a third analog signal value at the input pin that is outside of the first input range; and providing an indication of an open circuit condition at the input pin when the second output signal crosses the first threshold.

A microphone assembly includes a transducer and a processing circuit. The processing circuit includes an analog-to-digital converter (ADC) configured to receive, sample and quantize an electrical signal generated by the transducer to generate a corresponding digital signal. The processing circuit includes a feedback path including a digital loop filter configured to receive and filter the digital signal to provide a first digital feedback signal and a digital-to-analog converter (DAC) configured to convert the first digital feedback signal into a corresponding analog feedback signal. The processing circuit additionally includes a summing node configured to combine the electrical signal and the analog feedback signal.

A configurable analog to digital converter (ADC) is provided. The configurable ADC includes a comparator receiving and comparing a first analog voltage signal to a second analog voltage signal V-DAC and outputting a signal C-OUT that is responsive to a result of the comparison, an integrator operating on C-OUT and outputting an N-bit value, a digital-to analog converter (DAC) converting the N-bit value to the second analog voltage signal V-DAC, and an integrator, the integrator including the N-bit memory, which is coupled to an arithmetic logic unit (ALU), the N-bit memory and ALU cooperating to perform operations using both the N-bit value and C-OUT. The configurable ADC is configured to operate in more than one mode selected from a plurality of selectable ADC modes.