Other Parts Discussed in Thread: TPA3255, LM5010
Tool/software:
Hey,
I have a board with two TPA3255 designed which actually works so far.
The function is given as long as the supply voltage PVDD remains below approx. 32..35V.
PVDD currently comes from a laboratory power supply with current limiting. Without the current limitation, the TPAs would destroy themselves, which has already happened. (Short circuit between PVDD and GND).
The 12V is generated as in the Eval board with an LM5010 and LM2940. Reset is enabled via a controller.
I have made a testboard before this design where the TPA worked without problems.
Actually the current design should be better. At least not bad, since only equivalent or better components were used and the layout is also better in principle.
It makes no difference whether I hold a TPA in reset or not, both always show the same behavior. I have already disconnected the connection between the two and inserted another capacitor so that the second one also works on its own.
I'm just really surprised that under a certain voltage everything works without problems and from a certain point it gets completely out of control. Sometimes it works at 40V, sometimes only 35V. But every reset is unpredictable.
I have added a circuit diagram
Maybe someone has a good idea.
Thanks in advance
Best regards
Tobias
4540.tpa3255.pdf
