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TPA2013D1 amplifier no output signal

J Toulmin
Prodigy 30 points

Our new layout with the TPA2013 boost/amplifier IC has a problem.

The boost section works fine (3Vin and 5.5Vout) but the amplifier outputs remain at ground even with 1Vpp input signal. The two active low shutdown pins are both driven high and boost is working so presumably the amplifier should be on. The input signal is single ended sine 1Vpp 500Hz into the IN+, the IN- is grounded, both through 1uF caps. The load is 4 ohms through LC filters as shown in the datasheet.


Has anyone else had trouble like this? Any advise would be appreciated.

Thanks JT

  • 0
    TI__Mastermind 20085 points
    Hi JT

    Welcome to E2E, thank you for your interest in our products.
    Could you please provide us a schematic to support you of a better way?

    Best Regards
    Jose Luis Figueroa
    Audio Applications Engineer | A-Team
  • 0 in reply to José Luis
    Prodigy 30 points

    TPA2013scJT.pdfHi Jose - thanks for taking an interest, here's my schematic - JT

  • 0 in reply to J Toulmin
    TI__Mastermind 20085 points
    Hi JT

    The schematic seems to be right. You could measure the device's output without filter in order to discard an issue with output filter.
    Please let me know your opinion.

    Best Regards
    Jose Luis Figueroa
    Audio Applications Engineer | A-Team
  • 0 in reply to José Luis
    Prodigy 30 points

    Hello Jose


    You were correct! After removing the output filter and directly driving the load, the amplifier functions. Thanks for the good advise.

    We are seeing a large 600Khz noise component in the output however, and I suspect this may be an EMI problem. So we will probably have to revisit the output filter design.

    On another note, the datasheet shows a few examples of how to use the shutdown pins to enable just the booster, or just the amplifier, but there is no guidance on how these pins are normally handled when both the the booster and the amplifier are used together.

    So here is my question; Is there a recommended sequence or timing normally used for start-up and shutdown of the audio function to prevent click, pop, or any other undesirable behavior?

    thanks JT

  • 0 in reply to J Toulmin
    TI__Mastermind 20085 points

    Hi JT

    You could refer to the Class-D LC Filter Design and Filter-Free Class-D Audio Amplifiers application reports to find more information regarding output filter design.

    In order to avoid these kind of problems, you should refer to the Detailed Design Procedure subsection to find detailed information how to perform a correct design. We always recommended to follow our EVM layout.  

    Best Regards
    Jose Luis Figueroa
    Audio Applications Engineer | A-Team