I am working on a 21569 based design, using the EZ-KIT as a reference for a lot of things.
When it comes to power supplies, I am confused as to why the VDD_REF supply is coming from a pretty expensive low noise linear regulator when the main 4 output switching supply (ADP5054) is already generating a 1.8V supply (which is actually being used for almost nothing in the system).
I don't see anything in the datasheet about VDD_REF needing to be ultra low noise or anything like that.
Is there some good reason why this is done? I would just figure to use the 1.8V coming from the ADP5054 for VDD_REF.