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AIC3204 No Headphone Output through Digital Circuit

Part Number: TLV320AIC3204EVM-K

Hi all,

I am using the TLV320AIC3204EVM-K evaluation module with a few different microphones. While I am able to get an output through the headphones with an analog microphone and linking IN1_L to HPL, I cannot get any output if the signal has to go through the ADC/DAC.

I switched to using a digital microphone ( https://www.cuidevices.com/product/resource/cmm-4030dt-26354-tr.pdf ), connecting the mic's data output to GPIO and clock to MISO. In the software, I have chosen GPIO under "Digital Mic Input Pin" and Left ADC under "Digital Mic Routing". I have unmuted and powered on ADC Gain Control, and I have unmuted and powered on HP Output Gain Control. In the Digital Settings, I have selected MCLK and under CDIV_CLKIN I have powered on the Mux. Under "MISO and GPIO Control", I have selected MISO as a Clock output for digital microphone, and I have selected GPIO as a Digital microphone input.

Strangely, when I check the MISO test point, it just shows a high signal (~2.2V), not a clock.

Please let me know what settings I should change/add for this to work. Thank you!

  • Hi Delian,

    The device routes the ADC data to the I2S serial interface and receives data from the I2S serial interface and routes it to the DAC.

    The ADC data can be captured on a PC using the USB interface. The USB interface can also be used to send data to the DAC.

    Is that what you would like to achieve?

    Best Regards.

  • Thank you for the reply. I now understand that it is going through the PC, however if I set the input and output audio devices as the board, I cannot hear the microphone if I press "Listen" in Windows settings, for example. I do not understand why not, when Windows responds and shows that it hears the signal, and I can play system sounds through the board.

    I would like to route the input of the digital (or even analog, because I can't get that to work either) microphone through the DAC so that I can apply filters and/or AGC to the signal. I would like to hear this signal through the headphones, routed from DAC to HPO. By the way, I now see the clock signal on MISO, so that is no longer an issue. I just cannot hear anything except through the analog bypass.

    EDIT: A few minutes after this I was able to route the analog mic to play through the listen feature (my clock divider page was not set for USB Audio). Now, I just need help with setting up the digital mic to play in the same way, and applying adaptive filtering and AGC. Thank you!

  • Hi Delian,

    AIC3254's AGC operation is described in the application note - https://www.ti.com/lit/slaa474/. Additional info. is also available in Sect. 4.1.2.2 in the EVM user's guide - www.ti.com/lit/slau264a/.

    Please refer to the thread - https://e2e.ti.com/support/audio/f/6/t/582078 - for digital mic. configuration and to the thread - https://e2e.ti.com/support/audio/f/6/t/936894/- for adaptive filtering modes on ADC and DAC miniDSP.

    Best Regards.

  • Thank you for the link! I got the digital mic to work.

  • That is good to hear. Please let us know if you face any issues on the AGC or adaptive filters.

    Best Regards.