Just fell over this
Dallas DS18B20-PAR, 3 term TO-92 package.
For use in applications where the DS1820 is operated in the parasitic power mode. Term 1 is GRD, term 2 is DQ. Term 3 is not used, but may be grounded
What is parasitic power mode :?: :?:
Doesn't the non par of the Dallas use just 2 wires ???