TPA3255 Reference Design Class D Amp with PFFB

This board follows closely the TI EVM implementation as far as mode switches etc. Please refer to the section on PBTL in this document.

https://www.ti.com/lit/ug/slou441/slou441.pdf

Essentially you will want to set the DIP switches for M1=off and M2=on per:
1750446037344.jpeg

And connect C and D input to GND.

This is the diagram for the other stereo BTL and SE quadrophonic modes:
1750446160784.png
 
Can you show me a sketch or block diagram of the amp and how it is connected to audio source and output load etc? Also, detailed photos of the top and bottom side of the boards and how the audio signal is connected? If it works on stereo BTL, parallel BTL mode should be a simple setting away.

Input A and B should be balanced audio input and C and D should be grounded. But it is also important to see how the jumper 0ohm resistors are connected on the bottom side. A fault could be related to having the midpoint output touching ground?

Congrats on having it work in stereo BTL mode! That’s a big milestone and shows that your assembler has done a great job.