CPC H03M 1/468 (2013.01) [G10L 15/22 (2013.01); H03G 3/3005 (2013.01); H03M 1/462 (2013.01); H04R 3/00 (2013.01)] | 10 Claims |
1. An audio analog-to-digital converter (ADC) for supporting voice wake-up, comprising:
a programmable gain amplifier having an input terminal for receiving an audio signal;
a bypass switch having an input terminal for receiving an analog audio signal; and
a successive approximation ADC having input terminals respectively connected to output terminals of the programmable gain amplifier and the bypass switch;
wherein the programmable gain amplifier is configured to gain and amplify the audio signal, the bypass switch is configured to bypass the programmable gain amplifier when turned on, and output the analog audio signal;
wherein the successive approximation is configured to perform analog-to-digital conversion with noise shaping on the analog audio signal after gain amplification at a first sampling rate/oversampling rate when the audio ADC is in a normal working mode, and the successive approximation is configured to turn off noise shaping when the audio ADC is in a sleep mode, perform analog-to-digital conversion on the analog audio signal output by the bypass switch at a second sampling rate/oversampling rate, and output the analog audio signal after the analog-to-digital conversion to a digital signal processor (DSP) to wake up the DSP; and
wherein the first sampling rate/oversampling rate is greater than the second sampling rate/oversampling rate.
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