Temperature of MIC29300 is very high.

[diepvu1805]

Hi all,
I am using MIC29300-5.0BU in my design. But I have a issue with temperature of MIC29300.
When I supply 12VDC to Vin and the load is very low (100mA). MIC29300 is very hot although I used PCB heat sink for TAB (package TO263) with size: 12x12mm.
But when I used Vin 6VDC. I haven't meet that. Temperature of MIC29300 is low.
In the my other board, I use MIC29302BU and Vin 12VDC but temperature is low.
I don't explain that.
Could you help me, please?
Thank,

 

[dick_freebird]

Pdiss=(VIN-VOUT)*IIN so you have roughly 7X the power
dissipation in the 12V case. So expect 7X the temp rise.

Board as heat sink is only as good as your airflow.

 

[mtwieg]

That's just how linear regulators are. The formula dick posted is correct. Another way to look at it is in terms of efficiency. With linear regulators, efficiency=Vout/Vin. If you're stuck with a given Vin and Vout, and you want higher efficiency than that, then you need a switching supply.

 

[raylay]

That's just how linear regulators are. The formula dick posted is correct. Another way to look at it is in terms of efficiency. With linear regulators, efficiency=Vout/Vin. If you're stuck with a given Vin and Vout, and you want higher efficiency than that, then you need a switching supply.

The LDO low efficent,let more power convert to heat. if you let 12V to 5V, better use DCDC.

 

[diepvu1805]

Thank you for helping me. I thinhk, I should use the switching solution.