Use of microphone capacitance as a switched capacitor in an input network of a delta-sigma modulator

摘要

In accordance with embodiments of the present disclosure, a method and apparatus for providing a digitized microphone signal to a digital processing device may include an analog signal path portion, a digital signal path portion, and a control circuit. The analog signal path portion may have an audio input configured to receive an analog input signal indicative of audio sounds incident upon an audio transducer. The digital signal path portion may have an analog-to-digital converter for converting the analog microphone signal to the digitized microphone signal. The control circuit may be configured to control a magnitude of the analog input signal or a derivative thereof in order to reduce audio distortion occurring in either or both of the analog signal path portion and the digital signal path portion.

主权项

1. An input network for a delta-sigma modulator having a feedback digital-to-analog stage and at least one integrator stage including an input integrator stage, the input network comprising:
a plurality of sampling capacitors, wherein at least one of the plurality of sampling capacitors comprises a microphone capacitance of a microphone transducer, and further wherein the microphone capacitance is variable and indicative of audio sounds incident upon the microphone transducer; and wherein: during a first phase of a clock signal, the one or more sampling capacitors sample an input signal wherein the input signal is a function of the microphone capacitance; and during a second phase of the clock signal, the input network charge transfers the input signal onto an input of the input integrator stage.