LM5164: Device output range

Hi,

I can find the output info of LM5164 is Vout 1.2v to Max 90v,

I tried webench to create circuit, but output only allow 1.2v to max 50v in webench, do you know the reason?

Is it a hardware limit? Or other reason?

I am looking for a buck converter can output 12v to 90v.

Thanks.