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TPA3123D2: Amplifier output cut-off

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Replies: 8

Views: 58

Part Number: TPA3123D2

Dears Sirs, I have a problem with TPA3123D2 amplifier. It worked ok, but at this moment when I rise input signal level, the output is cut-off, current consumption latch in 170mA and the chip start hot.
I thought the speakers was demaged because if speakers are desconected it does not happen, but I has changed speakers and the situation is the same...
My circuit is very similar to descrived on "TPA3123D2EVM - User Guide" document.
I am desoriented... I has chequed the power suply, and it's ok.
Can any help my and suggest some measurement to confirm if I need replace TPA3123D or other asociated component?
Thanks in advance.


Ezequiel.-

  • Hi Ezequiel,

    Did you check the output power when issue happened? Did you check output current?

    What's about PVDD and laod impedance?

    I also suggest you can reduce the input level when issue happened. it can approve OC fault or OT fault.

    Regards,

    Derek 

  • In reply to Yanming Gong:

    Hi Derek, thanks very much for your reply.
    I checked output (meassure V and I on speakers) when issue happens and its becomes the same as active mute option, only difference is that the power source current latchs at 170mA (source voltage 27V) and the TPC3123D2 beginning hot and keep heating, up still unplugging the speakers.

    This leads me to think that excessive consumption occurs on TPA3123 or an asociated output component.

    In the issue state, if I reduce input signal level nothing change and the TPA31223D2 does not restore output, but if I reduce the signal level and enable / disable mute signal, the TPA yes restore output...
    I think that TPA is enabling short circuit protection but I can`t understand what causes it... I changed the speakers but nothing progress...
    About the input impedance, can this or another asosiated input component cuse the issue when does not appears if speakers are unpligging although increased input level signal?
    I really apreciate your help.
    Best Regards,

    Ezequiel.-

  • In reply to Ezequiel Yedynak:

    Hi Ezequiel,

    From your description, I think maybe OT or OC, or both issue happened.

    You can add heat-sink or fan to reduce the heat to check if the issue gone. And you can also check the output current value.

    Because TAP3123 OC is not latched, if OC happened, reducing output current will recover output. So I prefer OT issue.

    Regards,

    Derek

  • In reply to Yanming Gong:

    Hi Derek, thanks for your answered and time to suggest a solution.

    I think issue OT it's not likely given that it's active when the internal IC temperature exceeds 150°C and I can have my finger on the chip all time. Only up to 5 seconds after issue, the chip begins to heat up. (The chip heat up after output cut-off but not before).

    Also, if OT is active, the chip can't cool down quickly enough to turn the output back on in the time it takes to lower the input level and turn mute on / off

    On issue and mute state, the output current value is 7,6mA RMS. 

    I'm still disoriented...

    Best regards,

    Ezequiel.-

  • In reply to Ezequiel Yedynak:


    Hi Ezequiel,

    Please share your schematic to us if possible.

    Let me review the schematic.

  • In reply to Yanming Gong:

    I am not sure I can do it because it is part of a commercial equipment, and I do not violate intellectual rights ... I share it only with some component values.
    If you need to know another component value, please let me know.
    I really appreciate your help.
    Best regards.


    Ezequiel.

  • In reply to Ezequiel Yedynak:

    Hi Ezequiel

    What's the output power when issue happened?

    What's the RC circuit on output? I suggest you can simply hardware design firstly, only kept LC filter.

    Regards,

    Derek  

  • In reply to Yanming Gong:

    Dear Sirs, I´m sorry for my delay.
    I have solved the issue. In the nex days I will write more details.
    Thanks you for your time and availability.
    Best regards,

    Ezequiel.-