There is a recommended power up and down sequence for the RF-ADC supplies for safe operation. The following figure shows the recommended sequence where the ADC_AVCC supply should be powered up after the ADC_AVCCAUX supply is brought up, and powered down before the ADC_AVCCAUX supply is brought down.
There is no specific delay time between supply ramps as long as a sequence is followed/respected.
This can be enabled if the implemented power management has Power Good and Enable pins
which are common on most regulators. The Power Good
indicator of the ADC_AVCCAUX can be used as theEnable
control of the ADC_AVCC regulator. Look at the power distribution network on the
AMD ZCU216 customer board as a reference, or
contact your local FAE. AMD recommends full
switched mode power supply solutions for the data converter analog supplies due to the
increased power efficiency over low-dropout (LDO)-based solutions for most
applications.