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  • TI Thinks Resolved

TS3A227E: TS3A227 pop sound on power up

Part Number: TS3A227E

Hi all,

 My customer use TS3A227 in their Lenovo dock project. Lenovo complain about the pop issue when they power up their dock and connect its phone jack to an active speaker: 2 pop sound (maybe near 2KHz frequency) is heard. And we can see there's 2 pulse (5mV DC level) shown on L/R channels. We think that's detection function for 3/4 pole headset. but...

1. There's no pop sound heard by their TS3A225 product.

2. There's no pop sound founded when they connect their amp into jack.

 Is anything we can do to reduce the pop(detect) sound on power up.... And why TS3A225 don't have the sound?

 Thanks for your kindly help.

Best regards,

Gary Teng

  • Hi Gary,

    We will analyze the difference and get back to you soon.

    Fan Wang

  • Hello Gary,

    The TS3A227E does not put a signal voltage on the L channel.  During detection this pin is grounded.  The TS3A227E is not connected to the R channel so it cannot be causing any noise on that pin.  Is it possible to remove that TS3A227E from the board and see if the noise is still present?

    Regards,

    Andrew

  • In reply to Andrew_Mason:

    Hi Gary,

    We haven’t heard back from you, I’m assuming you were able to resolve your issue. If not, just post a reply below (or create a new thread if the thread has locked due to time-out)

    Thanks,
    Adam
  • In reply to Andrew_Mason:

    Hi Andrew,

     We remove the audio source / IC in front of TS3A227 and still can see the small signal shown while powering up the system. So we think 227 might need a detect sequence -- although it's small and can't be heard in HP. FYI and thanks for your help.

    Best regards,

    Gary.

  • In reply to Adam Torma:

    Hi Adam,
    Acturally we don't solve the issue but we try to discuss with customer to describe 227 need a detect process in start up. Will let you know if end customer has more feedback about it. Thanks for your help.

    Best regards,

    Gary

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