PIC AD + Vref- using external IC

[jorge]

i may be missing something ..but in my manual chapter 13 is instruction set summary ...and the one for the AD is the chapter 11...
I saw both...but i really dont know what are you leading me in :-) ?
BTW , i also believe in always RTFM :-) ...

I will explain better my problem , my sensor always outputs ( in standby status 1.8v , and it increases like 0.2mv until it reaches the 5v - since i am using the AD with 0 to 5v refs, and so i make a simple offset routine to "reset it" but ...this way i am only able to read it to 5v ..losing the "end part output above 5v ” ...so what i am trying to do is starting in 1.8 as 0 and going til "5+1.8 v" .... am i messing it up or thinking like a drunk guy ? cant I use an external IC to give to pin Vref- an V- reference different than 0 ?
i know i could workout with some opamps and rescale it ...but i thought i could be able to use Vref- to an voltage reference IC to achieve this ?!?

thanks.

Hi, Jorge

Did you , eventually, had a look to the PIC datasheet ... chapter 13 ( you know, the good luck number ... )

To be clear , at what is called, CVRef PIN ...

Alain