DS2501–UNW/DS2502–UNW
UniqueWareTM Add Only Memory
DS2501–UNW/DS2505–UNW
021998 1/1
SPECIAL FEATURES
•512 bits (DS2501–UNW) or 1024 bits (DS2502–UNW)
Electrically Programmable Read Only Memory
(EPROM) communicates with the economy of one sig-
nal plus ground
•Unique, factory-lasered and tested 64–bit registration
number (8–bit family code, 36–bit serialization, 12–bit
UniqueWare Identifier 5E7H, 8–bit CRC–tester)
assures absolute traceability because no two parts are
alike. Family code 91H for the DS2501–UNW, 89H for
the DS2502–UNW
•Built–in multidrop controller ensures compatibility with
other MicroLANTM products
•EPROM partitioned into two (DS2501–UNW) or four
(DS2502–UNW) 256–bit pages for randomly accessing
packetized data records
•Each memory page can be permanently write–pro-
tected to prevent tampering
•Device is an “add only” memory where additional data
can be programmed into EPROM without disturbing
existing data
•Reduces control, address, data, power and program-
ming signals to a single pin
•Directly connects to a single port pin of a microproces-
sor and communicates at up to 16.3k bits per second
•Presence detector acknowledges when reader first
applies voltage
•Low cost TO–92 or 8–pin SOIC and TSOC surface
mount packages
•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
321
DALLAS
DS2501/2
-UNW
TO–92
BOTTOM VIEW
1
2
3
4
8
7
6
5
TSOC PACKAGE
123
654
TOP VIEW
3.7 X 4.0 X 1.5 mm
8–Pin SOIC
(150 MIL)
321
See Mech. Drawings
Section See Mech. Drawings
Section
See Mech. Drawings
Section
PIN ASSIGNMENT
TO–92 TSOC SOIC
Pin 1 Ground Ground NC
Pin 2 Data Data NC
Pin 3 NC NC Data
Pin 4 –––– NC Ground
Pins 5 to 8 –––– NC NC
ORDERING INFORMATION
DS2501–UNW TO–92 package
DS2501S–UNW 8–pin SOIC package
DS2501P–UNW 6–pin TSOC package
DS2502–UNW TO–92 package
DS2502S–UNW 8–pin SOIC package
DS2502P–UNW 6–pin TSOC package
SILICON LABEL DESCRIPTION
The DS2501–UNW and DS2502–UNW are factory pro-
grammed versions of the DS2502 1K–bit Add–Only
Memory. They differ from the standard DS2502 in their
custom ROM family code 91H (DS2501–UNW) and
89H (DS2502–UNW) respectively, and the UniqueWare
Identifier 5E7 in place of the upper 12 bits of the stan-
dard serialization field. With the DS2501–UNW, the
upper two memory pages are not accessible; they
always read FFH and cannot be programmed. Other-
wise, the electrical and logical behavior is identical to
that of the DS2502. For technical details please refer to
the DS2502 data sheet.
The DS2501–UNW and DS2502–UNW are only avail-
able preprogrammed with customer specific and write–
protected UniqueWare data. Memory pages not used
for UniqueWare data can be programmed in the applica-
tion. For more details on UniqueWare, please refer to
the UniqueWare Project Setup Manual, available as
Application Note 99 from Dallas Semiconductor.
