Digital Temperature Sensor DS18B20

The DS18B20 digital thermometer provides 9-bit to 12-bit 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 requires only one data line (and ground) for communication with microcontroller. 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 microcontroller 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.

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
• Can be powered from data line. Power supply range is 3.0V to 5.5V
• Measures temperatures from 55C to +125C
• Thermometer resolution is user-selectable from 9 to 12 bits
• User-definable nonvolatile (NV) alarm settings with Alarm search command identifies devices whose temperature is outside of programmed limits.