Econo 1-Wire Digital Thermometer

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Status Explanations for product status codes

Part Number Status
DS1822 Active: In Production. See Ordering Information for details.


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 and TL 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.

Data Sheet

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Key Features

  • ±2°C accuracy from -10°C to +85°C
  • Measures temperatures from -55°C to +125°C (-67°F to +257°F)
  • 9- to 12-bit user-configurable resolution
  • 1-Wire interface requires only one port pin for communication
  • Has a 64-bit unique and unchangeable electronic serial number
  • Multi-drop capability for simplified distributed temperature sensing
  • Alarm function with user-defined non-volatile alarm settings
  • Converts temperature to 12-bit digital word in 750ms (max.)
  • No external components required to measure temperature
  • 3.0V to 5.5V supply range
  • Optional "parasite-power" operation (power derived directly from 1-Wire bus)
  • 3-pin TO-92 (DS1822) and 150mil 8-pin SO (DS1822Z) packages


  • Fire Alarm Systems
  • Hard Disk Drive
  • Storage Area Networks (SANs)
  • Telecommunications

Key Specifications:

Temperature Sensors
Part Number Sensor Type Interface Accuracy
Parasite Pwr. Temp. Thresh. Temp. Resolution
Multi Droppable Oper. Temp.
See Notes
DS1822  Local 1-Wire 2 Yes Programmable (NV)
Yes -55 to +125 $1.66 @1k
See All Temperature Sensors (111)

Pricing Notes:

This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


DS1822: Block Diagram
Block Diagram

More Information

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Information Index

Rev 2; 2007-09-25
This page last modified: 2009-10-23