Patent ID: 9699551
Date: 2017-07-04
CPC Classifications: H04R

Claim:
1. An analog signal processing circuit of a microphone, comprising: a bias circuit including a first sub-circuit which receives a signal from the microphone to output a first signal and a second sub-circuit which receives a reference voltage to output a second signal; and a fully differential circuit which receives the first signal and the second signal to output a fully differential signal, wherein the first sub-circuit and the second sub-circuit include a first bias sub-circuit and a second bias sub-circuit to apply bias voltages, respectively, wherein each of the first and second bias sub-circuits comprises a first pair of anti-parallel diodes and a second pair of anti-parallel diodes directly connected to the first pair of anti-parallel diodes, and wherein, in each of the first and second bias sub-circuits, a first respective reference voltage is applied to the first pair of anti-parallel diodes, a second respective reference voltage is applied to the second pair of anti-parallel diodes, and a middle value of the first and second respective reference voltages is applied to a node between the first and second pairs of anti-parallel diodes.