1.    According the data sheet  ,the SIX PINS(A4, A5, A10, A11, B4, B11) belong to the Analog Power Supply for the Clock Domain.

What is the role of the beads and resistors in this circuit in the demo board?   

2.According the Table 47 in the data sheet ,the tolerance  of  AVDD1 is ±2.5%,but voltage in the demo board (Generated by ADP1763) is 6.98K * 0.05 * 3.0 =1.047 ( over the 2.5% tolerance.)

Is there something wrong with The demo board  or the data sheet ?

3.According to the test, the ENOB cannot reach the data in the data sheet. The ENOB cannot exceed to 4.5bit.But when I increase the voltage of the AVDD1,the ENOB  and the current on the AVDD1  can be increased at the same.(Both voltage and current exceed the limits specified in the data sheet).

I am very confused about these questions and I look forward to your answers.