DS1822-PAR Datasheet

• 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

• Remote Sensing Applications

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 V_DD connection is required—the DS1822 must have V_DD connected to ground for operation in parasite-power mode.

The DS1822-PAR offers thermostatic functionality with user-programmable over-temperature (T_H) and under-temperature (T_L) 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.