Decisions, decisions! Extending your idea a little more, I've searched Maxim's web for serial I= 2C DACs (I already have I2C, so it makes little sense using a parallel DAC, isn't it?) and found the MAX5822 dual 12-bit i2c DAC. It has very little temperature variations (2.3ppm/=BAC), and unity-gain precission rail-to-r= ail op amps in the outputs. I'll look the datasheet in detail... Thanks again, Alvaro Deibe. ----- Original Message ----- From: "Brendan Moran" To: Sent: Thursday, July 04, 2002 8:08 PM Subject: Re: [PIC]: Precision 0.5V reference for AD > I still like the idea of using a smal DAC to provide the .5V reference. > With 4.5V as it's high-end reference, it would produce 0.494V > > Pretty close, I think. > > oh, well. > > --Brendan > > > The reference inputs on the PIC A/D can take up to 1mA during the > aquisition > > phase, so you'd want as low source impedance as possible if accuracy = is > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listserv@mitvma.mit.edu with SET PICList DIGEST in the body > > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body