AREF minimum operating voltage

Hi All

Changing to the internal AREF voltage from 5 to 1.1volts gives better resolution then measuring MV
My signal is 0 to 50 MV. Just doing a little more experimenting If I switch from internal 1.1volts to external I can put in whatever voltage less than 5 volts that I want. will it still operate properly with an external voltage of 100MV? at the AREF pin. What is the lowest possible voltage applied to the AREF pin that the ATMEGA will operate at.

DAS

Here is A post to read or another one

As far as I understand (I could not find it in the data sheets), the range of voltage that you can feed externally via AREF-pin for the Vref-point of the ADC Module is: 1.1V to 5V. And accordingly, the minimum analog signal that you can measure via any analog channel is: 1.08 mV; but, it is 3.26 mV taking into account the +/- 2-bit error of the ADC.

GolamMostafa:
As far as I understand (I could not find it in the data sheets), the range of voltage that you can feed externally via AREF-pin for the Vref-point of the ADC Module is: 1.1V to 5V.

Datasheet mentions a minimum Aref of 1volt.
You can maybe cheat a bit there, but I expect not much.
Maximum is of course VCC (should not put a 'voltage' label on that).
Leo..