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TLV320AIC3268: AIC3268 connects four voice MIC inputs, could the digital interface output four independent data in DSP mode

Part Number: TLV320AIC3268

TLV320AIC3268 is connected with four MIC inputs, and the output data from the digital interface is the mixing data of the four voices input; could TLV320AIC3268 output four independent data without mixing?

 Is 3268 default automatic put multi-input to mixing? Individual output is not supported?

  • User,

    while the TLV320AIC3268 has 4 mic inputs, it only has 2 ADCs. the Digital interface could output four data streams, but it sounds like you wanted the 4 mic inputs available individually. which is not possible with only 2 ADCs.

    best regards,
    -Steve Wilson
  • In reply to Steve-Wilson:

    It means that the 4 mics has been mixed defaultly before the ADC, it's not possible to get them individually ?

    In the miniDSP-A, i found this component called Multi_Channel digi( I2S out 8 channel ). this component could outputs 4 stere data( 8 channels ), but the  thay are all the same. I have tested it. 

    Could this component OR others impement eight different channels of data over the serial audio interface for device in TDM 

  • In reply to user5807315:

    User,

    it is not possible to get the 4 mics individually, at least not simultaneously. As stated before. There are only 2 ADCs (that means there are only 2 analog to digital converters) and thus only 2 digital signals coming from the decimation filters. (this is your Dec4xIn_1 block).
    The Multi-channel digital out is spitting out the same signal because you have it connected to a stereo splitter, this is really just duplicating the stereo input in to multiple stereo outputs. Its doing what you are asking it to do.

    if you want different outputs, you need to connect different inputs. can I ask what you are trying to do?

    the only way to get 4 microphone outs is to connect another ADC like the TLV320ADC3101, to the I2S input on the AIC3268, but it would be more reasonable to just connect the Dout of the ADC3101 to the same TDM Data line as the AIC3268.

    best regards,
    -Steve wilson
  • In reply to Steve-Wilson:

    Now I want to record sound using the TLV320AIC3268. I have independent source on the input (IN1L、IN2L、IN3L and IN4L).How can I get the different recording sounds by ASI1? I notice the datasheet refer to the DSP/TDM mode such as the following picture:

    And I find the component named by Multi_Channel_Digital_Out in the PurePath Studio. It’s help says that this component implements eight channels of data over the serial audio interface for the device in TDM.

    If it means that I can get the different recording sounds on the channel 1、channel 2、 channel 3 and so on? How can I using the Multi_Channel_Digital_Out or orthers in the PurePath Studio to accomplish my purpose?

  • In reply to user5807315:

    Hello User,

    As I've stated before there are only 2 ADCs on this device. If you want 4 independent channels, you will need another 2 channel ADC. Does that make sense?


    To be more specific, you can send IN1L to the Left ADC, and IN2L to the Right ADC, then you need another 2 channel ADC, the second 2 Channel ADC can be setup so that one input is sent to the left ADC and one to the Right then this device could be connected to the SAME I2S bus. OR if you are dead set on using this Multi-Channel_Digital_Out block, you could connect the second ADC to a second digital audio port on the AIC3268. Then connect the I2S input to the multi-channel Digital out block. That seems like a waste of processing though since a second device would be able to use the same TDM line.


    Question 1: Do you understand that there are only 2 ADCs on the TLV320AIC3268?
    Question 2: is it clear that with 2 ADCs you only have 2 independent inputs? (this means that IN1L,IN2L.IN3L and IN4L could not be independent digital signals after the ADC)


    best regards,
    -Steve wilson
  • In reply to Steve-Wilson:

    Thank you for your patience !  ( I understand Question 1 and 2 ... )

    By now i am sure The AIC3268 does not meet our demands and need to change one with 4 ADCs.

    thanks again.

  • In reply to user5807315:

    User,

    You can use multiple ADCs, do you need the DACs? Two TLV320ADC3101s would work. or if you need the DAC functionality, you could use one TLV320AIC3254 and one ADC3101.

    The data could still be on one TDM line, with multiple devices.

    best regards,
    -Steve Wilson