On 6/15/06, John Pearson wrote: > One advantage of I/O pin power is I can turn them off when not needed, > or if not getting correct info from them, saving battery power. You can power the DS1821 with an LDO with shutdown pin and control the LDO shutdown pin with an I/O port. > What power scheme would be the less likely to cause noise within the processor, I/O power or supply power? I think to use supply power might be better. However, it all depends on your setup. What is the analog reference voltage? Is it from a voltage reference or from filtered Vdd? -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist