DS18B20 18B20 18S20 TO-92 IC Thermometer Temperature Sensor AK31 Description: The DS18B20 digital thermometer provides 9-bit to 12-bit Celsius 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 -55C to +125C and is accurate to 0.5C over the range of -10C to +85C. 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 1-Wire 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.
Key Features Unique 1-Wire Interface Requires Only One Port Pin for Communication Each Device has a Unique 64-Bit Serial Code Stored in an On-Board 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 -55C to +125C (-67F to +257F) 0.5C Accuracy from -10C to +85C 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 Programmed Limits (Temperature Alarm Condition) Available in 8-Pin SO (150 mils), 8-Pin SOP, and 3-Pin TO-92 Packages Software Compatible with the DS1822