• Resolved

TPA2038D1: cutoff frequency and pop noise

Part Number: TPA2038D1

Hi all

Would you mind if we ask TPA2038D1?

Input coupling capacitor(AC coupling) on TPA2038D1YFFEVM is 0.1uF.

In case of AV = 6 dB   : the cutoff frequency will be 21.2Hz
In case of AV = 12 dB : the cutoff frequency will be 10.6Hz

In generally, we guess that the big capacitance value will be cause of pop-noise.
So, in case of using 0.1uF, as your experience, is it no level which you worry pop-noise?

If you have some advice, please let us.

Kind regards,

Hirotaka Matsumoto

  • Hi Matsumoto-san,

    The cutoff frequency shouldn't change with the gain. is it happening to you?
    As you mentioned, if the capacitor discharge time is very long (bigger capacitors), that could cause Pop noise.
    On the other hand, Pop noise is caused by an unbalanced input in order to avoid it, you can use differential input instead of single-ended input.

    Best Regards
    José Luis Figueroa
    Audio Applications Engineer
  • In reply to José Luis:


    I am using  TPA2038D1 audio amplifier part in my design. I have used 0.1uf capacitor in unbalanced input mode.  I have pop sound issues at both start and end of the audio file play. can you please  help me to solve this issue?. When audio file is played, Line voltage raised to 3.3V from 2.2 V . Also when  audio play stopped line voltage  is dipped to 0V from 2.2V. 



  • In reply to Tamilarasan E:

    Hi Tamilarasan,

    You need to create a new post in order to provide you support about your issue.

    Best Regards
    José Luis Figueroa
    Audio Applications Engineer