19-5101; Rev 4; 4/11
Thermochron iButton
DS921G
General Description
Features
®
®
♦ Digital Thermometer Measures Temperature in
The DS1921G Thermochron iButton 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 inter-
vals ranging from 1 to 255min can be stored. The his-
togram provides 63 data bins with a resolution of 2.0°C.
If the temperature leaves a user-programmable 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 addi-
tional 512 bytes of read/write nonvolatile (NV) memory
allows storing information pertaining to the object to
which the DS1921G is associated. Data is transferred
0.5°C Increments
♦ Accuracy ±±°C ꢀrom ꢁ-0°C to ꢂ+0°C ꢃ(ee the
Electrical Characteristics ꢀor Accuracy
(peciꢀication)
♦ BuiltꢁIn RealꢁTime Clock ꢃRTC) and Timer Has
Accuracy oꢀ ±ꢄ Minutes per Month ꢀrom 0°C to ꢂꢅ5°C
♦ Water Resistant or Waterprooꢀ iꢀ Placed Inside
D(9±0+ iButton Capsule ꢃExceeds Water
Resistant - ATM Requirements)
♦ Automatically Wakes Up and Measures Temperature
at UserꢁProgrammable Intervals ꢀrom ± Minute to
ꢄ55 Minutes
♦ Logs Up to ꢄ0ꢅ8 Consecutive Temperature
Measurements in Protected NV RAM
®
serially through the 1-Wire protocol, which requires only
♦ Records a LongꢁTerm Temperature Histogram
a single data lead and a ground return. Every DS1921G
is factory lasered with a guaranteed unique, electrically
readable, 64-bit registration number that allows for abso-
lute traceability. The durable stainless steel package is
highly resistant to environmental hazards such as dirt,
moisture, and shock. Accessories permit the DS1921G
to be mounted on almost any object including contain-
ers, pallets, and bags.
with ꢄ.0°C Resolution
♦ Programmable Temperature High and
Temperature Low Alarm Trip Points
♦ Records Up to ꢄꢅ Timestamps and Durations
When Temperature Leaves the Range (peciꢀied
by the Trip Points
♦ 5±ꢄ Bytes oꢀ GeneralꢁPurpose Read/Write NV RAM
♦ Communicates to Host with a (ingle Digital (ignal
at ±5.ꢅkbps or ±ꢄ5kbps Using ±ꢁWire Protocol
Applications
Common iButton Features
Temperature Logging in Cold Chain, Food Safety,
Pharmaceutical, and Medical Products
♦ Digital Identiꢀication and Inꢀormation by
Momentary Contact
Ordering Information
♦ Unique, FactoryꢁLasered, and Tested 6ꢅꢁBit
Registration Number ꢃ8ꢁBit Family Code ꢂ ꢅ8ꢁBit
(erial Number ꢂ 8ꢁBit CRC Tester) Assures
Absolute Traceability Because No Two Parts are
Alike
PART
TEMP RANGE
PIN-PACKAGE
DS1921G-F5#
-40°C to +85°C
F5 iButton
#Denotes a RoHS-compliant device that may include lead(Pb)
that is exempt under the RoHS requirements.
♦ Multidrop Controller ꢀor ±ꢁWire Net
♦ ChipꢁBased Data Carrier Compactly (tores Inꢀormation
♦ Data Can Be Accessed While Aꢀꢀixed to Object
Examples of Accessories
♦ Button (hape is (elꢀꢁAligning with Cupꢁ(haped
PART
DS9096P
DS9101
ACCESSORY
Probes
Self-Stick Adhesive Pad
♦ Durable (tainlessꢁ(teel Case Engraved with
Registration Number Withstands Harsh
Environments
♦ Easily Aꢀꢀixed with (elꢀꢁ(tick Adhesive Backing,
Latched by Its Flange, or Locked with a Ring
Pressed Onto Its Rim
Multipurpose Clip
Mounting Lock Ring
Snap-In Fob
DS9093RA
DS9093A
DS9092
iButton Probe
♦ Presence Detector Acknowledges When Reader
First Applies Voltage
Pin Conꢀiguration appears at end oꢀ data sheet.
♦ Meets UL 9±-, 5th Ed., Rev. ±99+ꢁ0ꢄꢁꢄꢅ; Intrinsically
(aꢀe Apparatus: Approved Under Entity Concept ꢀor
Use in Class I, Division ±, Group A, B, C, and D
Locations
Thermochron, iButton, and 1-Wire are registered trademarks of
Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products
±
For pricing, delivery, and ordering inꢀormation, please contact Maxim Direct at ±ꢁ888ꢁ6ꢄ9ꢁꢅ6ꢅꢄ,
or visit Maxim’s website at www.maximꢁic.com.