Danilo,
from the previous posts, people figured out the problem. some are due to wrong setting; some are due to out of date software. i believe TI stopped shipping CD in EVMs. you can always download latest software from TI web.
the 5V current will help you jduge if EVM is in right mode. 0.4A current should be drawn from 5V supply.
User manaul states below on AFE5805EVM GUI:
1. Set Address Byte(s) = 0 Data Byte(s) = 1. Click any space area to send command to AFE5805.
2. Set Address Byte(s) = 42 Data Byte(s) = 8081. Click any space area.
3. Set Address Byte(s) = 46 Data Byte(s) = 8208. Click any space area.
could you post a noise plot? are they random noise around DC or others?
Thanks!