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PCM5102A: DIR9001 connected to PCM5102A DAC Issues

Anthony Holton
Prodigy 10 points
Part Number: PCM5102A
Other Parts Discussed in Thread: DIR9001,

Hi Team

I have built a Headphone DAC Amplifier using the DIR9001 and PCM5102A DAC.
But I am having issues with getting any audio out of the current setup.
On Pin One of the DIR9001 I have connected an LED as show, to detect the presents of the BiPhase signal on RXIN pin

I have FMT0 and FMT1 pins pulled High and PSCK0 and PSCK1 pins pulled low.

Is they anything show in the attached schematic that would stop this circuit from functioning correctly?

I have tried 24bit 44.1khz sampling F to 24bit 96khz F to no avail.

All the power supplies look good and I can see some presents of data when I have RXin connected to my PC and playing some music

on pin14 Din on the PCM5102A DAC.
But no music coming out.

Can you please give me some insight as to what I am doing wrong here?



 

  • 0
    Guru 36510 points

    Hi Anthony-san,

    Please refer to the following PCM5101x schmetatic. There is an error in the connection method of capacitors for VNEG, CAPP, and CAPM. It seems that the charge pump doesn't work properly.

    Best regards,
    Kato

  • 0 in reply to Sadanori Kato
    Prodigy 10 points

    Hello Kato

    Thank you so much for replying, there was indeed an issue with the charge pump circuit.

    I have fixed this now, but sadly still no audio coming through.
    So still something not quite right.

    Cheers Anthony

  • 0 in reply to Anthony Holton
    Guru 36510 points

    Hi Anthony-san,

    Is -3.3V output to VNEG? PCM5102A may be damaged.

    Best regards,
    Kato

  • 0 in reply to Sadanori Kato
    Prodigy 10 points

    Just checked and there is -3.2v on pin 5 of VNEG and 3.2v across CAPP and CAPM pins, so it looks like the Charge pump is working ok.

  • 0 in reply to Anthony Holton
    TI__Expert 5665 points

    Hey Anthony, 

    Here are my comments:

    • Try using a digital signal to control the XSMT pin. It should meet the 20ns rise and fall time. You have a constant digital 3.3V on that pin

    Regards,

    Ore. 

  • 0
    Prodigy 10 points

    Well the DAC is now working, Thank you all for your helpful guidance, The final issue was with the SK0 master clock coming from the DIR9001, I had connected this on the PCB to pin 12 of the PCM5102A, SCLK input, A closer look at the data sheet revealed the a master clock was not needed as it has its own PLL onboard to generate its own master clock.

    Anyway cutting the link and grounding pin 12 of the PCM5102A allowed it to come to life and I am pleased to say its sounds very nice indeed.

    The only other thing I would like to sort out is the AUDIO Present output on Pin 1 of the DIR9001, when exactly or what exactly would trigger this output to go high and turn on the LED?

    Thanks again for those that contributed especially Kato for pointing out the charge pump schematic error. 

  • 0 in reply to Anthony Holton
    TI__Mastermind 21840 points

    Hi Antony,

    Please start a new post with your question regarding the DIR9001 in details so it can be useful for others when they search for issues.

    Thanks.

    Arash