Features and Benefits
- Digital Thermometer Measures Temperatures from -55°C to +100°C in Typically 0.2s
- Zero Standby Power
- 0.5°C Resolution, Digital Temperature Reading is Two's Complement of °C Value
- Access to Internal Counters Allows Increased Resolution Through Interpolation
- Reduces control, Address, Data, and Power to a Single Data Contact
- 8-Bit Device-Generated CRC for Data Integrity
- 8-Bit Family Code Specifies DS1920 Communications Requirements to Reader
- Special Command Set Allows User to Skip ROM Section and Perform Temperature Measurements Simultaneously for All Devices on the Bus
- 2 Bytes of EEPROM to Be Used Either as Alarm Triggers or User Memory
- Alarm Search Directly Indicates Which Device Senses Alarming Temperatures
The iButton® temperature logger (DS1920) provides direct-to-digital 9-bit temperature readings over a range of -55°C to +100°C in 0.5° increments. The iButton communicates with a processor using the 1-Wire® protocol through a hardware port interface. The port interface provides both the physical link and handles the communication protocols that enable the processor to access iButton resources with simple commands. Two bytes of EEPROM can be used either to set alarm triggers or for storing user data.
Armored in the DS1920, the thermometer can measure temperatures in demanding environments. Like every other iButton device, the DS1920 has a unique serial number. The 1-Wire interface reduces data output, address, and power to one line. A unique serial number allows multiple 1920s to share the same bus, with many sensors placed at different sites reporting to a single port on a processor. Multidropped DS1920s make the lowest-power temperature sensing network available inside buildings, equipment, or machinery and in process monitoring and control. With appropriate accessories the DS1920 easily attaches to an object or circuit board.
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
iButton Data Loggers5/17/2019
White Paper 2: Using the 1-Wire® Public Domain Kit7/16/2008
1-Wire Software Resource Guide Device Description7/8/2008
How to Power the Extended Features of 1-Wire® Devices6/17/2008
Software Methods to Achieve Robust 1-Wire® Communication in iButton® Applications9/11/2007
What Is an iButton Device?5/17/2006
Temperature-Based Fan Control Using the MAXQ2000 Microcontroller9/16/2005
1-Wire Master Device Configuration3/3/2004
Networked Temperature Monitoring7/22/2002
1-Wire® Tagging with XML6/7/2002
White Paper 5: Using 1-Wire APIs for Data Sheet Commands6/7/2002
1-Wire Communication Through Software5/30/2002
Using the DS2480B Serial 1-Wire® Line Driver3/12/2002
Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products3/29/2001
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
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