I have a small, simple circuit here. It doesn't work – both outputs (left and right side) are mute.
It uses the TDA7297 chip, and outputs 2 x 15W. I've wired 12V to '12V', and GND to -12V. I'm beginning to think that's the problem. Speakers need negative voltages as well… I've got a few LM337s laying around, should one of these be used to provide -12V?
If you need additional info, tell me.
Best Answer
The TDA7297 is specified for a single supply, up to 18V. So, it seems your mistake was connecting GND to -12V. It should be connected to ground - that is, the return of your +12V supply.
Because this chip drives the output in a bridge configuration, the differential output signal can go positive and negative with only a positive supply.
It's likely that you damaged the chip by supplying it with 24V when the specified absmax is 20V. You'll want to swap it out before trying again.