DESCRIPTION
The DS1822 digital thermometer provides 9- to 12-bit centigrade temperature measurements and has an alarm function with NV user-programmable upper and lower trigger points. The DS1822 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 ±2.0°C over the range of –10°C to +85°C. In addition, the DS1822 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.
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).
±2.0°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 of programmed limits (temperature alarm condition).
Software compatible with the DS18B20.
Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system.