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TLV320AIC3204 or 4 digital mic audio CODEC

Alexandre Bernussi
Intellectual 1955 points
Other Parts Discussed in Thread: PCM1865

Hi Team,

Looking for a CODEC solution which supports 4 mic inputs w/o the need for a DSP. Could the AIC3204 handle 4 mic inputs?

-Alex

ANSWER: The AIC3204 only has 2 ADCs so only 2 independent channels. You can mix more than 2 channels into an ADC. The AIC3268 & AIC3263 can support 4 digital mics at the same time because it has 4 decimation filters.

-Jorge

  • 0
    TI__Mastermind 28585 points

    Hi Alex,

    You could also look at the PCM1865 which has 4 channels.

    Best Regards,

    dave

  • 0 in reply to Converter Apps
    Intellectual 960 points

    Hi Alex,

    I use the AIC3204 in 64kbps sampling (8-bit @ 8kHz) with 4 independant mics and it works well. I use the CODEC in mono mode therefore the left channel is for mics 1 and 2, the right channel for mics 3 and 4. I can also mix the audio from 1/2 or 3/4.

    The LEFT channel gets configured through registers 52/54 and the RIGHT channel gets configured through registers 55/57.

    The 8kHz clock is basically the LEFT / RIGHT clock. Upon a L-to-H transition, it's one "pair", upon a H-to-L transition, it's the other "pair". So, when you are in the LEFT channel transition (whichever it is), you read either channel 1 or 3. When you are in the other transition, you read either channel 2 or 4. Then it's a matter of activating whichever mic you want in that transition. For instance:

    MIC 1 (L-to-H transition):

    SetRegister( 1, 52, 0b01000000 );
    SetRegister( 1, 54, 0b01000000 );

    MIC 2 (L-to-H transition): 

    SetRegister( 1, 52, 0b00010000 );
    SetRegister( 1, 54, 0b00000001 );

    MIC 3 (H-to-L transition): 

    SetRegister( 1, 55, 0b01000000 );
    SetRegister( 1, 57, 0b01000000 );

    MIC 4 (H-to-L transition): 

    SetRegister( 1, 55, 0b00010000 );
    SetRegister( 1, 57, 0b00000001 );

    That works well for me.