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PCM2903C: USB Sound card with PCM2903CDB - Analog OUT not working

Martin Likavec
Prodigy 90 points
Part Number: PCM2903C

Tool/software:

Hello TI,

I designed the sound card with PCM2903CDB (bought from mouser). 

I noticed at first turn ON and testing that PCM2903C successfully connect to laptop (USB AUDIO CODEC), picture below. Then I test HID control and this also worked. I saw in windows notification that volume changed or muted. 

      

After interface tests I found big problem that when I pressed play some music on laptop, the analog output not working. There is constant 3.3V level and nothing change. Measured on the IC side, on pins 16 and 15.After capacitor there was "zero".

Also, I measured it with AC setting in scope. In the picture below, is the measured waveform, but it will be only "noise".

Digital out (S/PDIF) seemed to work. I am not able to test with some audio device. I only measured the waveform with scope. Check picture below...

Only connected device (turned on), the music is not played.

 

Second scope screen, when music played. I know this is maybe hard to confirm that is working but you can see that waveform is different / denser.

Have you encountered anything similar? The IC is soldered properly without short or cold junction (picture below). Xtal is clocking correctly.

It is such a simple connection that there is no reason why it should not work. I'm quite disappointed with that. Is it possible that Mouser sold me a faulty/damaged PCM2903CDB?

 

PCM2903CDB schematic circuit below. Power port 3V3_VDD is from LDO and USB_C_VBUS is 5V from USB port. I did the tests without connected additional circuits to confirm that the problem is only in the PCM2903CDB.

Thank you for support.

Best regards,
Martin

  • 0
    TI__Mastermind 35340 points

    Hi Martin,

    I think it's unlikely that you received a faulty part, at least it was almost certainly working when it left the TI factory. 

    The SPDIF test is promising that you've at least correctly delivered audio from the PC to the codec (though not 100% sure without testing the SPDIF signal). Have you tried recording with the codec to see if the analog input is working? The analog in/out portions of the device should be powered from the same supplies so that should help confirm that the power is correct.

    Also do you see this problem with other devices or is it just the one faulty one? Have you tried replacing the device on the board?

    Best regards,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 90 points

    Hi Jeff,

    Thank you for valuable answer.

    I did not test analog IN of PCM2903CDB. I will try today and let you know.

    I also made a new order of PCM2903CDB from mouser. I hope it arrives tomorrow and I will try to replace the IC.

    Regards,
    Martin

  • 0 in reply to Martin Likavec
    TI__Mastermind 35340 points

    Hi Martin,

    Sounds good. Reply when you have made progress or learned more.

    Thanks you,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 90 points

    Hi Jeff,

    Still same issue with new PCM2903C. I checked all 3v3 and GND pins. Looks good.

    I tried the analog input.. And in PC I see that usb CODEC is connected as LINE IN, but when I source signal to analog IN, I cannot see it in PC. It looks like the whole analog section not working. 

    Any idea, please? I'm already desperate. It's so primitive that I don't even have anything to check here.

    Bad LOT series? Should I write to Mouser to provide me with a LOT number or for them to check with you if the series is really good?

    PCM board layout:

    Best regards,
    Martin

  • 0 in reply to Martin Likavec
    Prodigy 90 points

    Also Jeff, is it possible to sent me 1pcs of tested PCM?

    Do you check my schematic? Is it correct? 

    Could it be caused by a driver error?

  • 0 in reply to Martin Likavec
    TI__Mastermind 35340 points

    Hi Martin,

    Today is a U.S. holiday so tomorrow I will look more closely at your layout and get you a sample of the device directly from us. 

    If it is a device driver issue you can unplug the device, go to "hidden devices" in your windows device manager and choose to forget the codec. The next time you plug in the device it will reinitialize. 

    Best regards,

    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 90 points

    Hi Jeff,

    Thank you for information. The sample will be great! That way I could confirm unequivocally that the fault must be somewhere else.

    I tried to remove CODEC but this not solved the problem. I tested it on two different laptops with same result.

    Are you able to switch the conversation to non-public? Than I will share with you whole schematic and also I can share the brd, sch altium files.

    Regards,
    Martin

  • 0 in reply to Martin Likavec
    TI__Mastermind 35340 points

    Hi Martin,

    Sure thing. I have sent you a connection request on e2e. Once connected I can share you my email and we can share design files plus I can get your shipping information for the sample.

    Best regards,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 90 points

    Hi Jeff,

    I accepted your friend request. What next? I sent you a message.