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TPA2005D1: POP and Click elimination.

Amey Haldankar
Prodigy 120 points
Part Number: TPA2005D1
Other Parts Discussed in Thread: DRV135, DRV134, OPA2322

Hi,

I am using TPA2005D1 to drive my 8 ohm speaker, but it is producing audible pop and click sound whilst turning ON . How can we completely eliminate Pop and click noise?

I am giving 3.3 volt as a VDD. 

Thanks in advanced.

  • 0
    TI__Guru** 100525 points
    Hi Amey,

    Pop is reduced by using differential input for the amplifier, and also matching impedance between IN+ and IN-
    Any mismatch in impedance at the inputs will affect pop performance.
    There are several mentions of analog Class-D amplifiers and pop throughout the forum, you can search for "TPA20* pop" or similar.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    Prodigy 120 points

    Hi Ivan,

    Till now I was using single ended input to the amplifier.Could you help me in design of my project.Please have a look at the figure.Could you suggest me how to make differential input . 

    Thanks in advance.

  • 0 in reply to Amey Haldankar
    TI__Guru** 100525 points
    Amey,

    If your mic is single-ended output, you could try by placing a single-ended to differential amp like DRV135, this could also help to show similar input impedance for IN+/IN-.
    In addition it is recommended to use precision resistors to prevent mismatch between them.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    Prodigy 120 points

    Hi Ivan,

    I have two questions for you.

    1 )  DRV135 and DRV134 differential IC suggested by you is not useful in my application because in the datasheet of DRV13X they have mentioned that voltage supply range is Min +/- 4.5 volt. But In my project I'm using  +/- 3.3 regulated volt. Could you suggest alternative for DRV13X.

    2) I tried one experiment by introducing Opam with volume control in the feedback path before the TPA2005D1. I have attached the picture of experiment. what do you think about this experiment ?                          Does it  work to eliminate the pop noise ?

  • 0 in reply to Amey Haldankar
    TI__Guru** 100525 points
    Amey,

    I suggested DRV135 because this device takes a single-ended input into a differential output. You could try with opamp solution, however you should still take care of impedance matching at the inputs of TPA2005D1. Placing the opamp on only one side of TPA2005D1 input may not be too good for impedance match.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    Prodigy 120 points

    Hi Ivan,

    Thank you for your suggestion,

     

    My project runs on maximum 3.3 regulated voltage.  But DRV135 differential amplifier runs on Minimum 4.5 volt .

    Could you suggest any alternative differential amplifier for DRV135 or any other method to eliminate the pop noise.

    I have attached the screenshot of the (page number 17) DRV135 Datasheet.


     

     

  • 0 in reply to Amey Haldankar
    TI__Guru** 100525 points
    Amey,

    You could try by implementing a single-ended to differential circuit with a couple opamps. Based on the max voltage rail (3.3V) you might want to look into RRIO amplifiers, so you can use the most of your mic dynamic range as possible. OPA family might have some options, like OPA2322.
    Regarding the circuit you would need to use one of the opamps to drive the input of the second opamp. The second opamp will be unity-gain so that the output is the same amplitude as the first one, but only inverted in phase. Thus you would wire the amps in inverting mode.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators