ADC missing steps using 1 volt Vref

[Acetronics2]

Hi,

Just check your Pic Datasheet and see what are the ALLOWED ranges for Vref ...

Alain

[amgen]

Hi,
The V-in has to be less than V-ref at least by a little (dynamic range of v-in), so
use 5 Volt ref or use 50 ohm dropping R ( gives 1 volt at 20 ma)
Don

[Marv]

Alain,
I found in TABLE 26-24: - A/D Converter Characteristics, that (VREFH - VREFL) is 3v min.
Thanks for pointing me in the right direction.