DS18B20

Programmable Resolution 1-Wire Digital Thermometer

High-Precision Temperature Monitoring with Minimal Connections Ideal for Multisensor Systems


Description

The DS18B20 digital thermometer provides 9-bit to 12-bit Celsius temperature measurements and has an alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20 communicates over a 1-Wire® bus that 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 +125°C and is accurate to ±0.5°C over the range of -10°C to +85°C. In addition, the DS18B20 can derive power directly from the data line ("parasite power"), eliminating the need for an external power supply.

Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1-Wire bus. Thus, it is simple to use one microprocessor to control many DS18B20s 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.

DS18B20 FAQs DS18B20 FAQs
DS18B20: Block Diagram DS18B20: Block Diagram Enlarge+

Key Features

  • Unique 1-Wire® Interface Requires Only One Port Pin for Communication
  • Reduce Component Count with Integrated Temperature Sensor and EEPROM
    • Measures Temperatures from -55°C to +125°C (-67°F to +257°F)
    • ±0.5°C Accuracy from -10°C to +85°C
    • Programmable Resolution from 9 Bits to 12 Bits
    • No External Components Required
  • Parasitic Power Mode Requires Only 2 Pins for Operation (DQ and GND)
  • Simplifies Distributed Temperature-Sensing Applications with Multidrop Capability
    • Each Device Has a Unique 64-Bit Serial Code Stored in On-Board ROM
  • Flexible User-Definable Nonvolatile (NV) Alarm Settings with Alarm Search Command Identifies Devices with Temperatures Outside Programmed Limits
  • Available in 8-Pin SO (150 mils), 8-Pin µSOP, and 3-Pin TO-92 Packages

Applications/Uses

  • Agricultural Equipment
  • Audio Equipment
  • Climate Control
  • GPS Devices
  • Hard Disk Drive
  • Medical Equipment
  • Set-Top Boxes
  • Telecommunications
Part Number Sensor Type Interface Accuracy
(±°C)
Parasite Pwr. Temp. Thresh. Temp. Resolution
(bits)
Multi Droppable Oper. Temp.
(°C)
Budgetary
Price
See Notes
DS18B20  Local 1-Wire 0.5 Yes Programmable (NV)
9
10
11
12
Yes -55 to +125 $1.88 @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.

Technical Documents

Reference Schematic 5508 Create a 1-Wire Master with Xilinx PicoBlaze
App Note 5507 Understanding the DS1WM Synthesizable 1-Wire Bus Master
Tutorial 4700 Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing
Tutorial 4699 Overview of Sensor Signal Paths
Tutorial 4679 Thermal Management Handbook
App Note 4600 Simple Software Validates the Hardware CRC and Detects Errors in the Serial Bit Stream of 1-Wire® Thermal Devices
Reference Schematic 4477 Reference Design of a 1-Wire® Bidirectional Voltage-Level Translator for 1.8V to 5V
App Note 4377 Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers
App Note 4277 Getting Started with the MAXQ2000 USB Thumb Evaluation Kit
App Note 4255 How to Power the Extended Features of 1-Wire® Devices
App Note 3930 Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices
App Note 3754 Single-Wire Serial Bus Carries Isolated Power and Data
App Note 2965 1-Wire Master Device Configuration
App Note 2420 1-Wire Communication with a Microchip PICmicro Microcontroller
App Note 1100 White Paper 5: Using 1-Wire APIs for Data Sheet Commands
Reference Schematic 244 Advanced 1-Wire Network Driver
App Note 208 Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor
App Note 192 Using the DS2480B Serial 1-Wire® Line Driver
App Note 187 1-Wire Search Algorithm
App Note 162 Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment
App Note 158 1-Wire® Tagging with XML
Tutorial 148 Guidelines for Reliable Long Line 1-Wire Networks
App Note 126 1-Wire Communication Through Software
App Note 27 Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products

Quality and Environmental Data

Product Reliability Reports: DS18B20.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Tools & Models

DS18B20 IBIS Model

 

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Type ID PDF Title
Reference Schematic 5508 Create a 1-Wire Master with Xilinx PicoBlaze
App Note 5507 Understanding the DS1WM Synthesizable 1-Wire Bus Master
Tutorial 4700 Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing
Tutorial 4699 Overview of Sensor Signal Paths
Tutorial 4679 Thermal Management Handbook
App Note 4600 Simple Software Validates the Hardware CRC and Detects Errors in the Serial Bit Stream of 1-Wire® Thermal Devices
Reference Schematic 4477 Reference Design of a 1-Wire® Bidirectional Voltage-Level Translator for 1.8V to 5V
App Note 4377 Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers
App Note 4277 Getting Started with the MAXQ2000 USB Thumb Evaluation Kit
App Note 4255 How to Power the Extended Features of 1-Wire® Devices
App Note 3930 Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices
App Note 3754 Single-Wire Serial Bus Carries Isolated Power and Data
App Note 2965 1-Wire Master Device Configuration
App Note 2420 1-Wire Communication with a Microchip PICmicro Microcontroller
App Note 1100 White Paper 5: Using 1-Wire APIs for Data Sheet Commands
Reference Schematic 244 Advanced 1-Wire Network Driver
App Note 208 Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor
App Note 192 Using the DS2480B Serial 1-Wire® Line Driver
App Note 187 1-Wire Search Algorithm
App Note 162 Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment
App Note 158 1-Wire® Tagging with XML
Tutorial 148 Guidelines for Reliable Long Line 1-Wire Networks
App Note 126 1-Wire Communication Through Software
App Note 27 Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products