TPA3004D2 - How works short-circuit protection ?

Cyril BEGUET

Other Parts Discussed in Thread: TPA3004D2

Hi,

How works the short-circuit protection on TPA3004D2 ? Datasheet tells that this amplifier is protected against "output-to-output shorts, output-to-GND shorts, and output-to-Vcc short". But we easily burn our amplifier by shorting output (only one wire) to GND during a sound generation !

To understand what happend, we have some questions :

Is the output stage really protected against this failure ?

May we have a misstake on our schematics ?

How can we avoid damages in that case ?

Thanks for your help.

Cyril

over 12 years ago

0 Don Dapkus over 12 years ago

TI__Guru**** 189401 points

Hi, Cyril,

That's interesting. Yes, this device is fully protected, so something strange is going on here.

Can you post your schematics so I can take a look at them? It might also be a layout issue on your PCB.

It seems obvious, but the GND you're shorting the output to is the same GND connected to the IC, right? If they are isolated, then the protection may not work correctly.

-d2

0 Cyril BEGUET over 12 years ago in reply to Don Dapkus

Intellectual 460 points

Hi Don,

Is it possible to send you the shematics and layout in private ?

Cyril

0 Don Dapkus over 12 years ago in reply to Cyril BEGUET

TI__Guru**** 189401 points

Hi, Cyril,

Yes. I just sent you a friend request. Accept it, and you can send me a private message.

-d2

0 Don Dapkus over 12 years ago in reply to Don Dapkus

TI__Guru**** 189401 points

Hi, Cyril,

We are still working on this for you; I heard you may actually be referring to the line outputs, not the speaker outputs. Is this correct?

-d2

0 Cyril BEGUET over 12 years ago in reply to Don Dapkus

Intellectual 460 points

Hi Don,

I have received a response from your colleague. I’m analyzing it.

What do you mean about line or speaker outputs? We are only using LOUT channel, connected to a speaker. ROUT channel is disconnected (also power pin, that could be our problem).

Cyril

0 Don Dapkus over 12 years ago in reply to Cyril BEGUET

TI__Guru**** 189401 points

Hi, Cyril,

You somehow contacted our European PIC, and they contacted me, and told me it was your HP out that was the problem. I think they were just confused. Carry on.

Yes, our analysis shows you can't leave half the chip unpowered. I believe Brian made suggestions on how to fix the issue you're seeing.

-d2

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TPA3004D2 - How works short-circuit protection ?