Fisher Price My First Class D amplifier, and it died when power was applied. Of course.
It's a TDA8954J on a board of my own design, configured as BTL. I can't tell whether I have stuffed the design of it, or the PCB layout, or whether the chips are just eBay fakes - there are none in legitimate supply chains.
The output is -40V, so one of the output channels is hard over. The strange (to me) thing is that I could see R14 burn, and that's just there as a fault indicator on DIAG2. Something really bad had to happen inside the chip to send DIAG2 to one of the power rails.
Schematic and layout attached - any brilliant ideas? Suggestions for a different Class D all-in-one chip good for 300W/8R or 600W/4R that I can actually legitimately buy are also welcome...
It's a TDA8954J on a board of my own design, configured as BTL. I can't tell whether I have stuffed the design of it, or the PCB layout, or whether the chips are just eBay fakes - there are none in legitimate supply chains.
The output is -40V, so one of the output channels is hard over. The strange (to me) thing is that I could see R14 burn, and that's just there as a fault indicator on DIAG2. Something really bad had to happen inside the chip to send DIAG2 to one of the power rails.
Schematic and layout attached - any brilliant ideas? Suggestions for a different Class D all-in-one chip good for 300W/8R or 600W/4R that I can actually legitimately buy are also welcome...
Attachments
I bought them from a Chinese eBay seller, which is why I have no idea whether the conflagration was due to my own stupidity or the chips being some other device entirely with fresh paint on it.
I was hoping someone could look at my layout and go "aha! that right there is your mistake!".