Hello,
finally our board is ready to test. But we cannot get any output from the TPA3255.
One question is: M1 and M2 should read high level on min. 1.9V input. So we decided to set them with resistors from our 3V3 source.
Same source is used to tie RESET on a high level. Same GND-Plane for everything.
This is the signal we send to Input A and B:
If I send only a signal to Input A or B than the TPA3255 starts drawing current (about 1 Amp).
As soon as I apply the symmetrical signal, the input current is about 100 mA.
Tie RESET to GND reduces this to 85 mA.
So it looks like the chip is working somehow... but we cannot figure out what the problem is.
Did we do something wrong on the schematic?
Thank you and best regards