Quoting Olin Lathrop : > PICdude wrote: >> AFAIK, you can exceed the input impedance spec, but the A/D conversion >> time goes up. > > No. Source impedence has nothing at all to do with the A/D conversion time > since the source is decoupled from the sampling capacitor then. Maybe you're using A/D conversion time to mean just the time that the A/D converter is working/calculating (after the sampling cap is charged). I mean it to be the total time the code needs to get a valid sample (though your definition is probably correct). With a higher impedance, the sampling cap will take longer to come up to sampled voltage, hence increasing the total time required to get an A/D value. > ... -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist