Thanks Acetronics,sougata,

The idea for the digital sensor has crossed my mind. Actually i would prefer but i have the problem that the DS18B20 does not reach 150C ( that i what ) and the SMT 160-30 is not available here

I guess i will have to use the Vref. and have 2,5V there.

I never used the vref on this chip. Correct me if i'm wrong here:

In the data sheet it's marked Ra2 and RA3 as Vref- and Vref+.

I may use only the Vref+ pin and set the ADCON1 REGISTER (ADDRESS 9Fh) like :

ADCON1=%10100000

And i have to change the code to:

temp= (in */2500)>>2

Is this right ?