TPA3122D2: info on protection parameters TPA3122D2

Andrea Luciani

Part Number: TPA3122D2

hello, I'm using a TPA3122D2 BTL configuration for an amplifier with square wave input.
I'm feeding it at 17V and the load is composed of two 4 ohm speakers in series.
The problem that I am finding in some parts is that the current protection intervenes, because it feels that it detaches quickly and if the supply voltage is lowered a little, the protection no longer intervenes.
What I would like to ask is, what current value does the protection take, so that I can adjust before this phenomenon occurs.

Thanks
Andrew

over 4 years ago

0 Yanming Gong over 4 years ago

TI__Mastermind 19340 points

Hi Andrew,

Since it is old device, I will check with designer. When I get the data, I will reply to you.

Regards,

Derek

0 Yanming Gong over 4 years ago in reply to Yanming Gong

TI__Mastermind 19340 points

Hi Andrew,

TPA3122 OC current threshold is 5A.

Regards,

Derek

0 Andrea Luciani over 4 years ago in reply to Yanming Gong

Prodigy 30 points

in the technical document the current threshold is not reported after which the protection intervenes, but only the temperature intervention threshold.
So, by connecting the TPA3122D2 in the BTL configuration, and declaring the minimum threshold of resistance RL = 3.2 ohm, I have the net power supply voltage of the final 17V, why does the OC intervene in the power supply phase? that is, on the first rising front of the square wave, on some production parts, the OC intervenes, while in others it does not.
I enclose the scheme .. if anyone has any advice, it is welcome

0 Yanming Gong over 4 years ago in reply to Andrea Luciani

TI__Mastermind 19340 points

Hi Andrew,

For PVDD=17V, Load=3.2ohm case, the peak current will exceed 5A.

When power up, it will be larger start-current on putput.

I suggest you can check the output current using current probe.

Regards,

Derek

0 Andrea Luciani over 4 years ago in reply to Yanming Gong

Prodigy 30 points

ok .. thanks a lot of support. I verified that during normal use, the working current is about 4.85A, so maybe in the starting phase, considering the tolerances of the case, it can intervene.
I proceeded to lower the voltage slightly so as to fall within the threshold of 5A max.
Thanks so much..
Andrew

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TPA3122D2: info on protection parameters TPA3122D2