ADC for charge output sensors

An audio device comprising:

• a charge output sensor configured to sense sound and generate a sensor signal;
• an analog-to-digital converter (ADC) implemented to process the sensor signal, the ADC including a summing node for receiving the sensor signal from the charge output sensor, and an output node implemented to provide a digital signal representative of the sensor signal, the ADC further including a charge amplifier implemented to receive an analog signal from the summing node as an input analog signal and generate an output analog signal with a gain, and an ADC circuit implemented to generate the digital signal based on the output analog signal from the charge amplifier, the ADC further including a feedback circuit implemented between the output node and the summing node, the feedback circuit including a feedback digital-to-analog converter (DAC) implemented to receive as an input a sample of the digital signal from the output node and provide an analog feedback signal to the summing node, such that the analog feedback signal allows an adjustment of operation of the ADC circuit, the ADC further including a DC feedback circuit implemented between the output node and an output of the charge amplifier, the DC feedback circuit configured to allow compensation of a DC offset resulting from operation of the ADC circuit, the DC feedback circuit including a series arrangement of an IIR filter, a digital delta sigma modulator, and a DAC, such that an input of the IIR filter is coupled to the output node and an output of the DAC is coupled to the output of the charge amplifier;
• and
• a digital signal processor configured to process the digital signal provided at the output node.