10/21/
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1024 bits Electrically Programmable Read
Only Memory (EPROM) communicates with
the economy of one signal plus ground
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
Built-in multidrop controller ensures
compatibility with other MicroLAN products
EPROM partitioned into four 256-bit pages
for randomly accessing packetized data
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
Directly connects to a single port pin of a
microprocessor and communicates at up to
16.3 kbits per second
8-bit family code specifies DS2502
communications requirements to reader
Presence detector acknowledges when the
reader first applies voltage
Low cost TO-92 or 8-pin SO, SOT-23 (3-
pin), TSOC and flip chip surface mount
package
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 +50°C
DS2502
1 kbit Add-Only Memory
PIN ASSIGNMENT
TO-92
DS2502
NC 1
NC 2
DATA 3
GND 4
8 NC
7 NC
6 NC
5 NC
123
BOTTOM VIEW
8-PIN SO (150 MIL)
TSOC PACKAGE
GND 1
DATA 2
NC 3
6 NC
5 NC
4 NC
TOP VIEW
SOT-23 Package
Top View
3
09rr
1
2
1 = DATA; 2, 3 = GND
“rr” = Revision
09rrd
1
2
Flip Chip, Top View
with Laser Mark,
Contacts Not Visible.
“rrd” = Revision/Date
1 = DATA
2 = GND
See 56-G7010-001 for package outline.
NOTE: The leads of TO-92 packages on tape-
and-reel are formed to approximately 100 mil
(2.54 mm) spacing. For details refer to drawing
56-G0006-003.
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