Hi,
I have bought some samples of LP3783, here I would attach it's datasheet PDF, the problem is that their website is some how down and it's in Chinese
https://www.chip-hope.com 
I do not know why when I click the English version it would not load!

is this their correct website?
Also in the data sheet only a few parameters formulas are shown, so my question is how to design the passives including the transformer for this IC, any hints or a general calculator etc... is highly appreciated!