General Description
The DS1972 is a 1024-bit, 1-Wire® EEPROM chip organized as four memory pages of 256 bits each in a
rugged iButton® package. Data is written to an 8-byte
scratchpad, verified, and then copied to the EEPROM
memory. As a special feature, the four memory pages
can individually be write protected or put in EPROMemulation mode, where bits can only be changed from
a 1 to a 0 state. The DS1972 communicates over the
single-conductor 1-Wire bus. The communication follows the standard 1-Wire protocol. Each device has its
own unalterable and unique 64-bit ROM registration
number that is factory lasered into the device. The registration number is used to address the device in a multidrop, 1-Wire net environment.

Applications
Access Control/Parking Meter
Work-in-Progress Tracking
Tool Management
Inventory Control
Maintenance/Inspection Data Storage

Features
♦ 1024 Bits of EEPROM Memory Partitioned Into
Four Pages of 256 Bits
♦ Individual Memory Pages Can Be Permanently
Write Protected or Put in EPROM-Emulation Mode
(“Write to 0”)
♦ Switchpoint Hysteresis and Filtering to Optimize
Performance in the Presence of Noise
♦ IEC 1000-4-2 Level 4 ESD Protection (±8kV
Contact, ±15kV Air, Typical)
♦ Reads and Writes Over a Wide Voltage Range
from 2.8V to 5.25V from -40°C to +85°C
♦ Communicates to Host with a Single Digital
Signal at 15.4kbps or 125kbps Using 1-Wire
Protocol