TPA3245: Relationship between PVDD and output power

Downey Kim

Expert 2675 points

Part Number: TPA3245

Hi TI experts,

My customer asked if it is possible to output 80W on PVDD 24V at load 8ohm. I think it is impossible to calculate.

Using the formula below, it need at least 25.3V for 80W.

P=VI=V*V/R, 80W = V*V*8ohm -> V=25.3V

In case of PVDD 24V, is there a way to output power over 80W? (Speaker Load 8ohm)

Thanks,

Downey Kim.

over 3 years ago

0 Sam(MPAA) Zhang over 3 years ago

TI__Mastermind 19080 points

Hi Downey,

When considering how much output power can be delivered at a specific PVDD, we usually use sine wave to do the calculation.

The relationship is, without voltage clipping, the max output power = Vrms^2/R = PVDD^2/2/R; where R is the loading resistance. The "/2" divider comes from the RMS level = 1/sqrt(2) * peak level.

Thanks!

Regards,

Sam

0 Downey Kim over 3 years ago in reply to Sam(MPAA) Zhang

Expert 2675 points

Hi Sam,

So, your answer is that 80W output is not possible?

Thanks

Downey Kim.

0 Sam(MPAA) Zhang over 3 years ago in reply to Downey Kim

TI__Mastermind 19080 points

Hi Kim,

The answer is when you are using 24V PVDD and 8R loading, you can't achieve 80W without voltage clipping,

To achieve 80W, you can increase the PVDD or using lower resistance loading.

Regards,

Sam

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TPA3245: Relationship between PVDD and output power