Econo Parasite-Power Digital Thermometer

The DS1822-PAR is a digital thermometer with ±2°C accuracy over a -10°C to +85°C range and an operating temperature range of -55°C to +100°C. 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-PAR is a parasite-power only version of the DS1822 that is ideal for use in remote-sensing applications such as temperature probes. Parasite power eliminates the need for a local power supply since power is derived directly from the 1-Wire bus. The DS1822-PAR provides mechanical simplicity over the DS1822 for parasite-power applications because no VDD connection is required—the DS1822 must have VDD connected to ground for operation in parasite-power mode.

The DS1822-PAR offers thermostatic functionality with user-programmable over-temperature (TH) and under-temperature (TL) set points stored in on-chip EEPROM. Each DS1822-PAR features a unique and unchangeable 64-bit silicon serial number, which serves as the bus address for the sensor. This allows multiple DS1822-PAR devices to coexist on the same 1-Wire bus.

The DS1822-PAR is offered a 3-pin TO-92 package. Also available is the high-precision DS18B20-PAR, which provides ±0.5°C accuracy and is software-compatible with the DS1822-PAR.

Applications

* Remote Sensing Applications

* Derives power from data line (parasite power)does not need a local power supply

* ±2°C accuracy from -10°C to +85°C

* Measures temperatures from -55°C to +100°C (-67°F to +212°F)

* 9- to 12-bit user-configurable resolution

* 1-Wire interface requires only one port pin for communication

* Multidrop capability for simplified distributed temperature sensing

* 64-bit unique and unchangeable electronic serial number

* Alarm function with user-defined nonvolatile alarm settings

* Converts temperature to 12-bit digital word in 750ms (max)

* No external components required to measure temperature

* Ideal for remote sensing applications (e.g., temperature probes)

* 3-pin TO-92 package