> I guess "even if it's another part number" covers the 
> 16F506 (even though
> that's a different core), and the datasheet for that, in 
> table 13-1
> "Comparator Specs" gives internal voltage reference: 
> 0.550V min, 0.6V typ,
> 0.650V max.  I.e. +/-0.05V, or 8.3%.
>
> No figures on temperature or Vdd stability, just the 
> min/max range.
>
> Not high accuracy at all, although my own testing has 
> found it to be
> within 1% of 0.6V with Vdd=5V for a sample of 1...  Useful 
> for a
> non-demanding application, like warning/shutdown on low 
> alkaline
> batteries.


If it's based on a bandgap reference as it probably is then 
the stability is liable to be reasonable even if the initial 
value is not especially constant between processors.


        Russell

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist