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DEM-PCM2912AEVM: S/PDIF test error

Part Number: DEM-PCM2912AEVM
Other Parts Discussed in Thread: PCM2903C, PCM2902C

Hi Sirs,

As title, actually we have discussed in other side before

 

First, Could you double confirm our schematic again? (Actually we will design PCM2913C)

PCM2903C.output.pdf

Second, Update our test for your refer. Could you share have others way can test S/PDIF function?

  1. Change different source from our device ---fail
  2. Removed EVM S/PDIF out jumper ---fail
  3. Use Audio Gen output direct(no passed our device) S/PDIF to EVM ---fail

  • Hi, Shu-Cheng,

    The schematic seems fine. With the test setup I noticed that the output has a sampling rate of 48 KHz, have you configured the PCM2903C record sampling rate to 48K?. The sampling rate of the S/PDIF source should be the same as the PCM2903C, otherwise the part will keep playing the ADC content. I have verified this in my lab and the PCM2902CEVM is able to work with the BNC unbalanced oputput of the AP after the sampling rate is adjusted.

    Best  Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Hi Sirs,
    Thanks for your quick reply, may i know how to configured the PCM2902EVM record sampling rate to 48K??
    Thanks!!
  • Hi, Shu-Cheng,

    The recording sampling rate for the PCM2902C-EVM is set is configured by the host system. For example, in Windows, you need to go to Recording Devices, then select the USB AUDIO CODEC [PCM2902C], then go to the Advanced tab and change the Default Format to match the sampling rate of the S/PDIF input. By default, it seems that the PCM2902C-EVM is configured by windows to have a sampling rate of 44.1KHz, so you can also try changing the sampling rate of the S/PDIF signal to 44.1KHz to playback audio from the digital input .

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Hi Sirs,

    Thanks for your reply.

    We have try setting the same sampling rate but still couldn't heart the voice.

    Have other way to fix it?

    32K/16bit

    44.1K/16bit

  • Hi, Shu-Cheng,

    If the signal is valid and sampling rate of S/PDIF and device are the same, the part should start streaming the digital audio instead of the analog audio. I have verified this in my EVM. Apart from that, you must verify that the S/PDIF signal is compliant with the specs of the DIN pin of the PCM2902C as this EVM does not have a signal conditioning stage for the S/PDIF input.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer