need help AVCC and ADC

[dhimas]

Please correct me if im wrong, AVCC is used as voltage supplier for ADC and PORT A. If i used 8 bit ADC program (on AVR), and 5v on AVCC, i will have 255 output level which have about 0.019V per level (if the input is between 0-5v, where 5V input will resulting 255b, 2.5V resulting 128b, etc.).

so, my own conclusion is AVCC = ADC Vreff (im not 100% sure though)

Here comes the problem;

I work on a project that have input ranging about 0-1 volt, and i want to have more precise result.

beside using level converter, is it possible if i supply AVCC port with 1V so 1V input will resulting  255b, 0.5V resulting 128b?

im working with ATMega16 microcontroller and CVAVR

please forgive my bad language.

[AJISH ALFRED]

Hi Dhimas,

Why would you assume things when everything is written clearly in the Atmega16 datasheet.

 

AVCC

Analog Power Supply: This is the power supply voltage for analog 

part

For a normal use this pin must be connected

AREF

Analog Reference: reference for analog converter . This is the 

reference voltage of the A/D converter. As output, can be used by 

external analog

 

To know the range of reference voltage that can be applied, please check the ADC section or absolute maximum ratings in the datasheet.

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