Hmmmmmmm, I just left the circuit for about an hour and I don't think the drift ever stops. :P I had it on for about 20 minutes before I left and it made it to 260 mV when I came back it was at 350..... I'm guessing it's probably due to impresisions in the resistors.... Aaron -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads