Digital microphone and control method therefor

A digital microphone comprising:

• an acoustic sensor sensing an acoustic signal and transferring the acoustic signal to a voltage signal;
• a bias generator providing a bias voltage to the acoustic sensor;
• a first attenuator, coupled to the acoustic sensor at a first node, attenuating the voltage signal by a first attenuation value;
• a buffer, coupled to the acoustic sensor at the first node, receiving the voltage signal and buffering the voltage signal to generate a buffered voltage signal;
• an amplifier, connected to the buffer, receiving the buffered voltage signal and amplifying the buffered voltage signal to generate an amplified signal;
• an analog-to-digital converter, connected to the amplifier at a second node, receiving the amplified signal and converting the amplified signal to a data signal with a digital format;
• a second attenuator, connected to the analog-to-digital converter, attenuating the data signal by a second attenuation value;
• and
• a controller, connected to the amplifier at the second node, determining whether a magnitude of the amplified signal is larger than a reference value and adjusting the bias voltage, the first attenuation value of the first attenuator, and the second attenuation value of the second attenuator according to a determination result,
• wherein when the controller determines that the magnitude of the amplified signal is larger than the reference value, the controller controls the first attenuator to increase the first attenuation value, and further controls the second attenuator to decrease the second attenuation value.