adau1466 pll max frequency

Dear all,

I'm not able to reach core max frequency with my adau1466.

Xtal = 12.288

predivider = 4

pll mult = 80

12.288/4*80 = 245.76 MHz

If i try to run faster, the pll locks and unlocks few seconds later.

What do you think about this issue ? does anybody experienced the same behaviour ?