TPS54360B: Heat Issues faced

Pang

Part Number: TPS54360B

Hi Ti,

With the previous recommendation from previous thread that we need required the specs of Vin: 24V, Vout: +/- 12 Iout: 0.7mA. We have tested the split rail regulator design and found out the temperature of inductor increase rapidly when we draw 0.66A current from one side.

Test Methodology: A 5 ohm resistor is connected to the +3.3V power and Ground. The load draw about 0.66A.

The temperature hits 90 degree and continue increase until we turn OFF the power. In the calculator, we have calculated all the specs with ±1A, but currently the temperature don't allow us to draw current more than 0.66A.

Please help to advise.

over 4 years ago

0 Arief Hernadi over 4 years ago

TI__Mastermind 23815 points

Hi,

Do you know what is the power dissipation of the inductor?

Also what size of inductor that you use?

Do you have schematic/layout files that you can attached?

Thanks

-Arief

0 Pang over 4 years ago in reply to Arief Hernadi

Expert 2385 points

Hi Arief,

The inductor which is used exactly same with the one in the reference as below link, MSD1260-47KL. I have attached my schematic here.

http://www.ti.com/lit/ug/slvu374/slvu374.pdf

0 Pang over 4 years ago in reply to Pang

Expert 2385 points

Hi Arief,

Appreciate your advise as we're in the midst of troubleshooting.

0 Pang over 4 years ago in reply to Arief Hernadi

Expert 2385 points

Hi Arief,

May I have some updates?

0 Arief Hernadi over 4 years ago in reply to Pang

TI__Mastermind 23815 points

Hi,

In this app note the FB is taken from the primary side of the regulator instead of the secondary.

http://www.ti.com/lit/ug/slvu374/slvu374.pdf#page=10

The inverting buck boost flybuck normally regulate the primary side and what you get on the secondary does not have as much tight of regulation as the primary side of the IC.

Could you try to mimic the app note schematic in terms of how to connect the FB node?

Thanks

-Arief

0 Arief Hernadi over 4 years ago in reply to Arief Hernadi

TI__Mastermind 23815 points

Hi,

I hope you have resolved the issue, i will close this thread for now

Thanks

-Arief

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TPS54360B: Heat Issues faced