The DS1822 is a digital thermometer with ±2°C accuracy over a -10°C to +85°C range. Data is read out over a 1-Wire® serial bus in 2's complement format with 9 to 12 bits of resolution (user-programmable).
The DS1822 offers thermostatic functionality with over-temperature (TH
) and under-temperature (TL
) user-programmable setpoints stored in on-chip EEPROM. An internal flag is set when the measured temperature is greater than TH
or less than TL
. If thermostatic operation is not required, the two bytes of EEPROM reserved for TH
may be used for general-purpose nonvolatile storage.
Each DS1822 features a unique and unchangeable 64-bit silicon serial number, which serves as the bus address for the sensor. This allows multiple DS1822 devices to coexist on the same 1-Wire bus. The DS1822 may be locally powered via a 3.0V to 5.5V supply, or power can be derived from the 1-Wire data line ("parasite power").
The DS1822 is offered in 3-pin TO-92 (DS1822) and 150mil 8-pin SO (DS1822Z) packages. In addition, the DS1822 is available in a parasite-power only version, the DS1822-PAR
. Also available is the high-precision DS18B20
, which provides ±0.5°C accuracy and is software-compatible with the DS1822.