1-Wire Parasite-Power Digital Thermometer

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Status Explanations for product status codes

Part Number Status
DS18B20-PAR Active: In Production. See Ordering Information for details.


The DS18B20-PAR digital thermometer provides 9 to 12-bit centigrade temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20-PAR does not need an external power supply because it derives power directly from the data line ("parasite power"). The DS18B20-PAR communicates over a 1-Wire® bus, which by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of -55°C to +100°C and is accurate to ±0.5°C over a range of -10°C to +85°C.

Each DS18B20-PAR has a unique 64-bit identification code, which allows multiple DS18B20-PARs to function on the same 1-wire bus; thus, it is simple to use one microprocessor to control many DS18B20-PARs distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment or machinery, and process monitoring and control systems.

Data Sheet

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Key Features

  • Unique 1-Wire Interface Requires Only One Port Pin for Communication
  • Derives Power from Data Line ("Parasite Power")—Does Not Need a Local Power Supply
  • Multi-Drop Capability Simplifies Distributed Temperature Sensing Applications
  • Requires no External Components
  • ±0.5°C Accuracy from -10°C to +85°C
  • Measures Temperatures from -55°C to +100°C (-67°F to +212°F)
  • Thermometer Resolution is User-Selectable from 9 to 12 Bits
  • Converts Temperature to 12-Bit Digital Word in 750ms (max.)
  • User-Definable Non-Volatile Temperature Alarm Settings
  • Alarm Search Command Identifies and Addresses Devices Whose Temperature is Outside of Programmed Limits (Temperature Alarm Condition)
  • Software compatible with the DS1822-PAR
  • Ideal for Use in Remote Sensing Applications (e.g., Temperature Probes) That do not Have a Local Power Source


  • Remote Sensing Applications

Key Specifications:

Temperature Sensors
Part Number Sensor Type Interface Accuracy
Parasite Pwr. Temp. Thresh. Temp. Resolution
Multi Droppable Oper. Temp.
See Notes
DS18B20-PAR  Local 1-Wire 0.5 Yes Programmable (NV)
Yes -55 to +100 $2.40 @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.


Pin Configuration

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Information Index

Rev 1; 2003-11-19
This page last modified: 2008-12-02