FEATURES Unique 1-Wire® interface requires only one port pin for communication Each device has a unique 64-bit serial code stored in an onboard ROM Multidrop capability simplifies distributed temperature sensing applications Requires no external components Can be powered from data line. Power supply range is 3.0V to 5.5V Measures temperatures from C55°C to +125°C (C67°F to +257°F) 0.5C accuracy from C10°C to +85°C Thermometer resolution is user-selectable from 9 to 12 bits Converts temperature to 12-bit digital word in 750ms (max.) User-definable nonvolatile (NV) alarm settings Alarm search commａnd identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition) Available in 8-pin SO (150mil), 8-pin SOP, and 3-pin TO-92 packages Software compatible with the DS1822 Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system
DESCRIPTION The DS18B20 Digital Thermometer provides 9 to 12Cbit centigrade temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20 communicates over a 1-Wire bus that by definition requires only one data line (ａnd ground) for communication with a central microprocessor. It has an operating temperature range of C55°C to +125°C and is accurate to 0.5C over the range of C10°C to +85°C. In addition, the DS18B20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply. Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1Cwire bus; thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment or machinery, and process monitoring and control systems.
