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 -55°C to +125°C and is accurate to ±0.5°C over the range of -10°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 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 -55°C to +125°C (-67°F to +257°F) |
| • | ±0.5°C Accuracy from -10°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 Programmed Limits (Temperature Alarm Condition) |
| • | Available in 8-Pin SO (150 mils), 8-Pin µSOP, 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.