In our customer's boards, the 1.8V supplies (i.e. CORE_VDD and 1V8_AVDDx) are powered up at the same time prior to the other supplies (i.e. IO_VDD and 2V5_AVDDx). Until the other supplies are powered up, the other supplies seem to rise to approximately 1V with the 1.8V supplies.
Does DP83865 have the characteristic that can cause such a behavior?
Best regards,
Daisuke