Other Parts Discussed in Thread: TPS53353, , TPS543B20, TPS53355
Hello,
My customer would like to design Vin=12V, Vout=5V and Iout(max)=16A buck convertor at Ta=85oC.
They are considering either TPS56221 or TPS53353, take a look at datasheets and implemented WeBench simulations.
The results are as follows.
TPS56221 TPS53353
Theta-ja in the datasheet 34.6oC/W 27.2oC/W
Theta-ja at WeBench 17.3oC/W 27.2oC/W
Tj at Ta=85oC 119.272oC 130.385oC
Looking at datasheet, TPS53353 Theta-ja is lower than TPS56221.
But, looking at WeBench simulation results, TPS53353 Tj is higher than TPS56221.
This confuses my customer.
WBDesignTPS56221.pdfWBDesignTPS53353.pdf
Q1:
Why TPS56221 Theta-ja is different between datasheet spec and Webench simulation?
JEDEC spec PCB is used for both datasheet and Webench at TPS53353, but different PCB is used for only TPS56221 WeBench simulation? Why?
Q2:
Actually, which device has more margin thermally?
Which does TI recommend?
Best regards,
K.Hirano