TPS54231- Power dissipation area requirements

srinivasaprasad saladi

Other Parts Discussed in Thread: TPS54231, TPS54332

Hi,

I want to use TPS54231 12V input, output required is 5v, 1.4A.

Power loss in TPS54231 is arround 1.7W, I need to operate this device in loco ambient 55°C.

Please specify how many thermal vias are required & Copper area in the PCB required for heat dissipation, off course junction

temperature should not exceed 85°C.

Regards,

SrinivasaPrasad.

over 13 years ago

0 JohnTucker over 13 years ago

TI__Guru**** 191445 points

I calculate the power dissipation for that application as 0.54 W not 1.7 W. Even then, the junction temperature will be around 109 C. The TPS54231 does not have a thermal pad. I suggest you look at TPS54332 instead. Use 6 thermal vias under the IC and 1.5 x 2 inches exposed copper on the back side and large fill areas to connect grounds on the topside should keep the junction temperature at 82 C.

0 srinivasaprasad saladi over 13 years ago in reply to JohnTucker

Intellectual 295 points

Hi John,

Thank you for answer can you send calculations for TPS54231 & TPS54332, so that i can design my future power supplies.

Thanks & regards,

SrinivasaPrasad.

0 JohnTucker over 13 years ago in reply to srinivasaprasad saladi

TI__Guru**** 191445 points

I just used webench to estimate teh power dissipation and then used the published theta JA to estimate the junction temperature. I think webench may also calculate the junction temp.

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TPS54231- Power dissipation area requirements