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