MAX 10 (10M08SAE144) ADC: Vref at 2.5 V, and VCC_ONE at 3.3 V

Hi,

Thanks for getting back to me.

We want to utilize the ADC of the 10M08SAE144. We are considering to use a reference voltage on the ADC_VREF pin of 2.5 volt - this is the same voltage that is used in the "MAX 10 10M08 Evaluation Evaluation Kit" design. Note that in this design the VCC_ONE pin is at 3.3 volt. So far, so good.

The problem is that in Table 34 (see link above) it is stated that "External reference voltage" for the ADC should be between VCC_ONE – 0.5 and VCC_ONE. This translates to between 3.3-0.5 = 2.8 volt and 3.3 volt. Since a reference voltage of 2.5 volt (like in the eval kit) is outside of this range, this choice of reference voltage appears to be in conflict with the datasheet (Table 34).

This contradiction forms the basis for my questions:

1) Can anyone come up with a good explanation as to why the development kit is not made in accordance with the device datasheet?

2) What are the consequences/risks in violating this datasheet requirement?

3) Is this simply an error in the datasheet?

Erik