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TPA3110D2 POP Noise issue

Marco Yang
Prodigy 10 points

Hi Sir,

We found that there is a POP noise when the SD# PIN is enabled.

We attempted to connect an SD# to a button for control. Whenever PVCC and AVCC are active, regardless of when I enable the SD# PIN, it results in a POP noise.

Can you provide suggestions to reduce POP noise?

If there's a POP noise when SD# transitions, how can we resolve this?

Thanks.

  • 0
    TI__Mastermind 19820 points

    Hi,

    The pop is mainly related to audio input DC caps mismatch. 

    You can check the audio input DC caps 1uF mismatch, or change the caps value to 0.47uF to double confirm pop noise.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 10 points

    Did you mean change to 0.47uF of C7299,C7300,C975,C7039? Right?

    I found out another issue for gain 1,0, we hear louder scratching noise, seem CRB has same issue. Do you have idea to reduce it?

  • 0 in reply to Marco Yang
    TI__Mastermind 19820 points

    Hi,

    Yes, those caps change to 0.47uF. And the caps should be put close to AMP. The trace from AMP to caps should be same.

    Could you tell us more detail information about another issue? and test condition.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 10 points

    Does C978 C976 need to change to together?
    I change caps to 0.47uF of C7299,C7300,C975,C7039,C978,C976 before.
    Total 6 caps, but pop noise is not impact.
    If change to 10uF, pop noise become big.

    My customer need to set gain1,gain0 to 10.
    When we boot up in BIOS menu, I hear louder scratching noise, just like the sound of ambient space.
    If gain1, gain0 set to 00, scratching noise can be reduce.

    This noise i have no idea to solved.

    By the way, can we change the gain value at any time, For example, it is 00 during the boot process and 10 when entering the windows OS.

    Because other vendor IC can use I2C to change gain vaule in time, so I think above behavir is ok, right?

    Thanks.

  • 0 in reply to Marco Yang
    TI__Mastermind 19820 points

    Hi

    Accroding to your description, I think the pop noise is related to audio input. With Gain increasement, pop will increase.

    You can short to audio input to GND through C7299, C7300, and check pop noise again.

    Are C978 C976 required by Codec side? If not, you can reduce the value.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 10 points

    Hi 

    MB Test

    1. Pop noise.

    I try to change that del R1390/R1392 and add R1395/R1396 to 22K from codec output.

    When I use botton to control SD# enable or Disable, pop noise has occurred.

    Of couse short Amp input to GND, pop has not occurred, but it is not normal work.

    2. scratching noise

    According to the above experiment, this also has scratching noise.

    CRB Test.

    1. When I power on amp PVCC and AVCC and touch SD# switch then pop noise has occurred.

    2. At the same time, this also has scratching noise. We don't connect input.

    PS: CRB Line-in connector normal short to GND, need to plug wire to separate it.

    There seems to be a scratching noise present when the amplifier is turned on.

  • 0 in reply to Marco Yang
    TI__Mastermind 19820 points

    Hi,

    Did you short audio input to GND through 1uF caps? Do not short input to GND directly.

    If there is no pop when audio intput short to GND through 1uF caps, it means noise is from audio input side, not AMP side. 

    Please double check audio input noise!

    Regards,

    Derek