DS1985 Datasheet, PDF (1/25 Pages) Dallas Semiconductor – 16-kbit Add-Only iButton

DS1985
16-kbit Add-Only iButton^TM
www.dalsemi.com
SPECIAL FEATURES
§ 16384 bits Electrically Programmable Read
Only Memory (EPROM) communicates with
the economy of one signal plus ground
§ EPROM partitioned into sixty-four 256-bit
pages for randomly accessing packetized
data records
§ Each memory page can be permanently
write-protected to prevent tampering
§ Device is an “add only” memory where
additional data can be programmed into
EPROM without disturbing existing data
§ Architecture allows software to patch data by
superseding an old page in favor of a newly
programmed page
§ Reduces control, address, data, power, and
programming signals to a single data pin
§ 8-bit family code specifies DS1985
communications requirements to reader
§ Reads over a wide voltage range of 2.8V to
6.0V from -40°C to +85°C; programs at
11.5V to 12.0V from -40°C to +85°C
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
F3 MICROCAN ^TM
0.36
3.10
0.51
c 1993
16.25
YYWW REGISTERED RR
ED
0B
000000FBC52B
17.35
§ 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 16.3k bits per
second
§ Standard 16 mm diameter and 1-Wire^TM
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 (application pending)
F5 MICROCAN ^TM
5.89
0.36
0.51
c 1993
YYWW REGISTERED RR
6D
0B
000000FBD8B3
16.25
17.35
DATA
GROUND
DATA
GROUND
All dimensions shown in millimeters.
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