This may get you started: http://www.national.com/an/AN/AN-31.pdf. You select the opam that fulfills your specs and is available where you live. VV Magnus von Rosen wrote: . *I have a vague memory of what an OP-AMP does. * *What should I get and what should I look for when selecting the OP-Amp.* --------------------------------- Do you Yahoo!? The New Yahoo! Shopping - with improved product search -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads