Sensitive silicon microphone with wide dynamic range

摘要

A silicon microphone on which four acoustic transducers are integrated, having different values of sensitivity and, accordingly, different values of dynamic range; the analog acoustic signals are supplied from the four acoustic transducers to the integrated circuit device, and are converted to digital acoustic signals; the digital acoustic signal output from the acoustic transducers with relatively high sensitivity acoustic transducers are normalized with respect to the digital acoustic signal output from the acoustic transducer with lowest sensitivity, and the normalized digital acoustic signals are selectively formed into a composite acoustic signal depending upon the sound pressure of sound waves so that the dynamic range is expanded without sacrifice of high sensitivity in the low sound pressure range.