The present disclosure refers to a digital
microphone device providing a single-bit
Pulse Density Modulation PDM output
signal. The digital
microphone comprises a
microphone, arranged to convert an acoustic input
signal into an analog electrical
signal, and a
preamplifier, having a variable
gain, arranged to receive the analog electrical signal and to provide an amplified analog electrical signal, depending on the variable
gain. The variable
gain depends on a gain
control signal. The digital microphone further comprises an Analog-to-
Digital Converter block, arranged to receive the amplified analog electrical signal and to convert it into a respective
digital signal; and a compensation block, arranged to receive the
digital signal and to perform a digital operation on such
digital signal, on the basis of a compensation signal, to generate a compensated signal. Furthermore, the digital microphone comprises an
Automatic Gain Controller block 25, arranged to detect the digital signal and to generate said gain
control signal, on the basis of the detected digital signal. The
Automatic Gain Controller block is further arranged to generate the compensation signal, on the basis of the
control signal, and to provide the compensation signal to the compensation block, to compensate a variation of the digital signal resulting from the variable gain of the
preamplifier. Finally, the digital microphone device comprises a conversion block, arranged to receive the compensated signal and to convert it into the single-bit PDM output signal.