WEBENCH® Tools/LM3150: Ron package 0805

Part Number: LM3150

Tool/software: WEBENCH® Design Tools

Hi,

I got a design of the LM3150 with Webench, where the Ron =105 Kohm with package 0805, over the alternate all eligibles.  The input voltage max is 24V.

Even the small footprint design option makes the same result.

I am skeptical. According to the datasheet, the RON pin is not a big current flow path.  With intuition, 0603 packages would be sufficient, I think.

Is there a stringent reason to use the bigger "0805" package for the Ron?

Thanks,

J.H.Kim