TPS650864 Vref not stable.
hello every one,I want to make a pcb with xczu15eg and use tps650864 for power.
I meet some strange problem.
the ldo3p3 and the ldo5p is not correct.
here is the scope
the vref :
the ldo3p3
the ldo5p:
my sche is as below:
and here is my pcb layout.
I have change three ic,and the vref on scope is all the sam.
I also try the move the cap of vref by cut the pcb and make it near to the ic.But the wave didn't go well.
So please any suggestion???
