DS18B20 Programmable Resolution 1-Wire Digital Thermometer 1-WIRE WRITE ZERO TIME SLOT tSLOT tREC START OF NEXT CYCLE tLOW0 1-WIRE READ ZERO TIME SLOT tSLOT START OF NEXT CYCLE tREC tRDV 1-WIRE RESET PULSE RESET PULSE FROM HOST tRSTL tRSTH PRESENCE DETECT 1-WIRE PRESENCE DETECT tPDIH tPDLOW Figure 2. Timing Diagrams Pin DescriptionPINNAMEFUNCTIONSOµSOPTO-92 1, 2, 6, 2, 3, 5, 7, 8 6, 7 — N.C. No Connection 3 8 3 VDD Optional VDD. VDD must be grounded for operation in parasite power mode. 4 1 2 DQ Data Input/Output. Open-drain 1-Wire interface pin. Also provides power to the device when used in parasite power mode (see the Powering the DS18B20 section.) 5 4 1 GND Ground www.maximintegrated.com Maxim Integrated │ 4