StratixIVGX core voltage supply issue from devkit

[Altera_Forum]

Hi dears: 

 I'm study Altera's IVGX SI devkit schematic, and prepare to design my board. But i was confused by the core voltage of the schematic as attachements shown.  The 4601 can't convert 14V to 0.9 according the ltm4601 datasheet, and how Altera guys to get the 0.9V from LTM4601?

[Altera_Forum]

Yes, according to the LTM4601 datasheet 14 V or even 20V to 0.9V are not guaranteed by design. I guess, the Altera design is relying on the typical ton(min) rather than the maximum value, as good design practice would require. So you should go for a different switcher device. 

 Similar problems exist with most synchronous switchers. Usually, they require to reduce the switching frequency for large voltage ratios, but this option doesn't exist with LTM4601.

[Altera_Forum]

Thanks for ur reply!