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DS1921G
EVALUATION KIT AVAILABLE
Thermochron iButton Device
General Description
The Thermochron® iButton® device (DS1921G) is a rugged, self-sufficient system that measures temperature and records the result in a protected memory section. The recording is done at a user-defined rate, both as a direct storage of temperature values as well as in the form of a histogram. Up to 2048 temperature values taken at equidistant intervals ranging from 1 to 255min can be stored. The histogram provides 63 data bins with a resolution of 2.0°C. If the temperature leaves a userprogrammable range, the DS1921G also records when this happened, for how long the temperature stayed outside the permitted range, and if the temperature was too high or too low. An additional 512 bytes of batterybacked SRAM allow storing information pertaining to the object to which the DS1921G is associated. Data is transferred serially through the 1-Wire® protocol, which requires only a single data lead and a ground retu.