TPA3118D2 Power Amplifier

Hello, Chaitu. Welcome to the Audio Amplifier E2E Forums! Looks like you're new here. I hope you find this place useful and engaging.

Unfortunately, FAULTZ is a pretty simple signal. It's pulled low when when either over an over temperature condition or an over current conditon occurs. There's some ORing logic at work there, just telling you, "There's a problem!" but not much else.

The way you can confirm what caused the FAULTZ change is your testing setup. For over temperature, you can use a temperature sensor on your board or a thermal probe applied to the top of the TPA3118D2 package, where temperatures around 100 °C or more are indicative. To see that the device faults for over current and not over temperature, try running a burst signal into the amplifier, which won't make the switching FETs hot enough to go over temperature, but can produce greater than the limiting output current. A current probe across your inductor or even on the line after your filter can help you see that current is too strong. On page 19 of the data sheet, there is an explanation of how to clear the latch by tying FAULTZ to SDZ, but these conditions are otherwise not self-clearing.

Over voltage is a self-clearing error, so when it occurs, the amplifier will restart and try for normal operation unless it see the condition again. For persistent over voltage and under voltage, you will see the amplifier switch on and off quickly.

I hope this is useful to you.

Best Regards,
Matt

Hi Matt Lauer,

Thanks for your reply.

So, I need to use:
external temperature sensor for over temperature and
Current probe across inductor to verify over current etc.,

So, the IC's (TPA3118D2) FAULTZ signal will not tell what type of error might have occurred.

Do I need to use any external circuitry for over voltage and under voltage indication ?

Thanks & Regards
Chaitu