TPA3251: TPA3251

Sorry, fault and clip OTW remains low...

DVDD and GVDD remains also low level (about 0,4 V). I haven't test to force reset High. I had made a first prototype wich is exactly the same, it work fine.

Hi Georges

   I'm sorry, seems we don't know the background of your problem. Could you please give us more details? 

Hi Shadow He

My problem looks like the same than Zhang Liang one.

I made a prototype of a amplifier with TPA3251 (BTL stereo). The first one work fine, but the second no (same PCB, same schematic). The problem is when power on, the fault and clip OTV pins remains active (low level), and reset remains  also low level. Yet the reset pin is controlled by a µC with a 300 ms delay for power on (3,3V) a TCM809 wich add a 240 ms delay.

I have tested all supply pins, PVDD is 36V, GVDD and VDD is 12V, but DVDD, AVDD and VBG is < 0.5V.

For now I have unsoldered the TPA 3251, and the pin out of the TCM809 (wich is the input pin reset of the TPA3251) is high level (3,28V) after ~500ms powered on. With the TPA implemented, reset remains low...

It's look like a hardware problem (bad welding or something like this), but perhaps a well know problem.

Thanks

Hi Georges

the DVDD, AVDD, VBG voltage is abnormal. protection was triggered.

several things want to confirm:

1.is that possible the chip have any problem.

2.you said another circuit work normally, are these 2 circuit work at the same power supply with same load resistance?

3.for both fault and clip otw is low, OTE or OLP been triggered, does you chip or surround circuit have any thermal issue be found?

thanks.

Jess

Hi Jesse

Yes, the two circuits work exactly with same power supply (36V) and load resistance (8 r). I didn't detect any température problem (The TPA3251 is cold, and others chip also).

I think you're right with a problem of TPA chip. I'm going to test the circuit with a new one. Answer as soon as possible ;-)

Thank you