Part Number: TPA3255-Q1
I am designing a class-D amplifier as a school project, and decided to use the TPA3255-Q1 as the IC of choice. I have used the schematic in the datasheet and the evaluation board schematic as references, and I'm using the PBTL configuration with a 4 ohm speaker as the load, and have built a PCB. I am using 48V into PVDD and 10.6V into GVDD, using a power supply that can provide 10.4A at 500W. The 10.6V comes from voltage regulators, and this voltage was confirmed to make sure regulators worked correctly.
Almost every external component (output filter inductors and capacitors, capacitors and resistors around IC) are all the same as on the evaluation board. The same op-amps (NE5532ADR) were used to create the differential input from a single ended input, and confirmed it produced a differential input on an oscilloscope. While testing, the IC was well cooled with a fan and a considerably sized heat sink was installed.
Powering on the device, everything is normal, fault and clipping pins are pulled high (3.3V) as they should be. This is with the speaker plugged in, but no input running through the IC. Immediately once a differential input is applied to inputs A and B, the speaker produces one popping sound, then the IC shuts down and requires a restart.
I believe there is some type of over current shutdown occurring, but can't figure out why. I am using a 22k ohms resistor into the OC_ADJ pin.
If anyone has had similar issues with any related ICs, any testing ideas or help would be greatly appreciated.