• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 30 subscribers
  • Views 187 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM4853: Shutdown pop and click

Jesper Noer
Prodigy 10 points
Part Number: LM4853


I'm designing a device that uses the SHUTDOWN function on this chip to suppress noise coming from other circuits. By shutting down the amp, these noises are not heard in the speaker.

Now my problem is that when I enable the amp by pulling the SHUTDOWN pin low, it gives a loud POP in the speaker which I wanted to avoid in the first place.

Is there any way to remove this loud POP or reduce it significantly? 

  • 0
    TI__Guru** 110815 points

    Hi Jesper,

    For pop noise mitigation you should look at the series caps along the signal path. The charge and discharge of these caps are the primary concern. Below are some things you can check:

    • Try changing the value of bypass capacitor. Larger value should increase the ramp time.
    • Are you using both BTL and SE outputs? If using BTL only, you may remove the output series capacitors Co. Otherwise you may change Co, Rpu and Rd; Co and Rd define a time constant for the charge/discharge, you can try different Rd values first to see how it affects the pop, then adjust Rpu to keep a similar voltage divider.
    • Similarly, you can change Ci and Ri components; adjust Ri and check how it affects the pop, then adjust Ci to keep the similar filter response.

    Best regards,
    -Ivan Salazar
    Applications Engineer