DS1822

Econo 1-Wire Digital Thermometer


Description

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.
DS1822: Block Diagram DS1822: Block Diagram Enlarge+

Key Features

  • Unique 1-Wire® Interface Requires Only One Port Pin for Communications
    • Can Be Powered from Data Line
    • Power-Supply Range is 3.0V to 5.5V
  • Reduced Component Count with Integrated Temperature Sensor and Interface
    • Requires No External Components
    • 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)
  • Simplifies Distributed Temperature Sensing with Multidrop Capability
    • Each Device Has a Unique 64-Bit Serial Code Stored in an On-Board Device
    • Flexible, User-Definable Nonvolatile (NV) Alarm Settings with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits
    • Software compatible with the DS18B20
  • Applications Include Thermostatic Controls, Industrial Systems, Consumer Products, Thermometers, or Any Thermally Sensitive System

Applications/Uses

  • Fire Alarm Systems
  • Hard Disk Drive
  • Storage Area Networks (SANs)
  • Telecommunications
Part Number Sensor Type Interface Accuracy
(±°C)
Parasite Pwr. Temp. Thresh. Temp. Resolution
(bits)
Multi Droppable Oper. Temp.
(°C)
Budgetary
Price
See Notes
DS1822  Local 1-Wire 2 Yes Programmable (NV)
9
10
11
12
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.

Tools & Models

DS1822 IBIS Model

 

Related Resources


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Precision Thermocouple to Digital Converter with Linearization

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