19-4864; Rev 4/11
DS1904
RTC iButton
SPECIAL FEATURES
. Presence detector acknowledges when reader
first applies voltage
. Meets UL 913, 5th Ed., Rev. 1997-02-24;
Intrinsically Safe Apparatus, Approved under
Entity Concept for use in Class I, Division 1,
Group A, B, C, and D Locations
. Real-Time Clock/calendar in binary format
. Uses the same binary time/date representation
as the DS1994 but with 1 second resolution
. Clock accuracy is better than ± 2 minutes per
month at 25°C
. Operating temperature range from -40°C to
+70°C
F5 MicroCan
. Over 10 years of operation
5.89
0.51
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
16.25
40
24
17.35
000000FBC52B
1-Wire
. Multidrop controller for MicroLAN
. Digital identification and information by
momentary contact
. Chip-based data carrier compactly stores in-
formation
IO
GND
. Data can be accessed while affixed to object
. Economically communicates to host with a
single digital signal at 16.3 kbps
. Standard 16 mm diameter and 1-Wire®
protocol ensure compatibility with iButton®
Device family
All dimensions are shown in millimeters
ORDERING INFORMATION
DS1904L-F5#
F5 MicroCan
# Denotes an RoHS-compliant device that may include
lead(Pb) that is exempt under the RoHS requirements.
. Button shape is self-aligning with cup-shaped
probes
. Durable stainless steel case engraved with
registration number withstands harsh envi-
ronments
. Easily affixed with self-stick adhesive back-
ing, latched by its flange, or locked with a
ring pressed onto its rim
EXAMPLES OF ACCESSORIES
DS9096P
DS9101
Self-Stick Adhesive Pad
Multi-Purpose Clip
Mounting Lock Ring
Snap-In Fob
DS9093RA
DS9093A
DS9092
iButton Probe
iButton DESCRIPTION
The DS1904 RTC iButton is a rugged real-time clock module that can be accessed with minimal
hardware. Data is transferred serially via the 1-Wire protocol, which requires only a single data lead and a
ground return. The DS1904 contains a unique 64-bit factory-lasered ROM and a real-time clock/calendar
1-Wire and iButton are registered trademarks of Maxim Integrated Products, Inc.
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