DS1994 Datasheet, PDF (1/22 Pages) Dallas Semiconductor – 4kb Plus Time Memory iButton

DS1994
4kb Plus Time Memory iButton
www.iButton.com
SPECIAL FEATURES
§ 4096 bits of Read/Write Nonvolatile
Memory
§ 256-bit Scratchpad Ensures Integrity of Data
Transfer
§ Memory Partitioned into 256-bit Pages for
Packetizing Data
§ Data Integrity Assured with Strict
Read/Write Protocols
§ Contains Real-Time Clock/Calendar in
Binary Format
§ Interval Timer Can Automatically
Accumulate Time When Power is Applied
§ Programmable Cycle Counter can
Accumulate the Number of System Power-
On/Off Cycles
§ Programmable Alarms Can Be Set to
Generate Interrupts for Interval Timer, Real-
Time Clock, and/or Cycle Counter
§ Write-Protect Feature Provides Tamperproof
Time Data
§ Programmable Expiration Date That Limits
Access to SRAM and Timekeeping
§ Clock Accuracy is Better Than ±2 Minutes/
Month at 25°C
§ Operating Temperature Range from -40°C to
+70°C
§ Over 10 Years of Data Retention
COMMON iButton^® FEATURES
§ Unique, Factory-Lasered, and Tested 64-bit
Registration Number (8-bit Family Code +
48-bit Serial Number + 8-bit CRC Tester)
Assures Absolute Traceability Because No
Two Parts Are Alike
§ Multidrop Controller for MicroLAN
§ Digital Identification and Information by
Momentary Contact
§ Chip-Based Data Carrier Compactly Stores
Information
§ Data Can Be Accessed While Affixed to
Object
§ Economically Communicates to Bus Master
with a Single Digital Signal at 16.3kbps
§ Standard 16mm Diameter and 1-Wire^®
Protocol Ensure Compatibility with iButton
Family
§ Button Shape is Self-Aligning with Cup-
Shaped Probes
§ Durable Stainless Steel Case Engraved with
Registration Number Withstands Harsh
Environments
§ Easily Affixed with Self-Stick Adhesive
Backing, Latched by its Flange, or Locked
with a Ring Pressed onto its Rim
§ Presence Detector Acknowledges when
Reader First Applies Voltage
§ Meets UL#913 (4th Edit.); Intrinsically Safe
Apparatus, Approved under Entity Concept
for Use in Class I, Division 1, Group A, B, C
and D Locations
F5 MICROCAN
5.89
0.36
0.51
© 1993
YYWW REGISTERED RR
61
04
000000FBD804
16.25
17.35
IO
GND
All dimensions shown in millimeters.
ORDERING INFORMATION
DS1994L-F5
F5 MicroCan
iButton and 1-Wire are registered trademarks of Dallas Semiconductor.
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