DS18B20 Datasheet

• Unique 1-Wire^® Interface Requires Only One Port Pin for Communication
• Reduce Component Count with Integrated Temperature Sensor and EEPROM
  • Measures Temperatures from -55°C to +125°C (-67°F to +257°F)
  • ±0.5°C Accuracy from -10°C to +85°C
  • Programmable Resolution from 9 Bits to 12 Bits
  • No External Components Required
• Parasitic Power Mode Requires Only 2 Pins for Operation (DQ and GND)
• Simplifies Distributed Temperature-Sensing Applications with Multidrop Capability
  • Each Device Has a Unique 64-Bit Serial Code Stored in On-Board ROM
• Flexible User-Definable Nonvolatile (NV) Alarm Settings with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits
• Available in 8-Pin SO (150 mils), 8-Pin µSOP, and 3-Pin TO-92 Packages

• Consumer Products
• Industrial Systems
• Thermally Sensitive Systems
• Thermometers
• Thermostatic Controls

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. 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.