DS1971-004-550/1+ - Maxim Integrated Products, Inc.

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19-4734; 7/09

DS1971

256-Bit EEPROM iButton

www.maxim-ic.com

SPECIAL FEATURES

 256-bit Electrically Erasable Programmable

Read Only Memory (EEPROM)

communicates with the economy of one

signal plus ground

 EEPROM organized as one 256-bit page

 64-bit one-time programmable application

programming

 Reduces control, address, data, power, and

programming signals to a single data pin

 8-bit family code specifies DS1971

communications requirements to reader

 Reads and writes over a wide voltage range

of 2.8V to 6.0V from -40°C to +85°C

F3 MicroCan

F5 MicroCan

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

 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 16.3kbps

 Standard 16mm diameter and 1-Wire

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

ORDERING INFORMATION

DS1971-F3+ F3 MicroCan

DS1971-F5+ F5 MicroCan

+Denotes a lead(Pb)-free/RoHS-compliant package.

EXAMPLES OF ACCESSORIES

DS9096P Self-Stick Adhesive Pad

DS9101 Multi-Purpose Clip

DS9093RA Mounting Lock Ring

DS9093F Snap-in Fob

DS9092 iButton Probe

iButton and 1-Wire are registered trademarks of Maxim Integrated Products, Inc.

DS1971

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iButton DESCRIPTION

The DS1971 256-bit EEPROM iButton is a rugged read/write data carrier that identifies and stores

relevant information about the product or person to which it is attached. This information can be accessed

with minimal hardware: for example, a single port pin of a microcontroller. The DS1971 consists of a

factory-lasered registration number that includes a unique 48-bit serial number, an 8-bit CRC, and an

8-bit Family Code (14H) plus 256 bits of EEPROM. The power to program and read the DS1971 is

derived entirely from the 1-Wire communication line. Data is transferred serially via the 1-Wire protocol

which requires only a single data lead and a ground return. The 48-bit serial number that is factory-

lasered into each DS1971 provides a guaranteed unique identity which allows for absolute traceability.

The durable MicroCan package is highly resistant to harsh environments such as dirt, moisture, and

shock. Its compact button-shaped profile is self-aligning with cup-shaped receptacles, allowing the

DS1971 to be used easily by human operators or automatic equipment. Accessories permit the DS1971 to

be mounted on printed circuit boards, plastic key fobs, photo-ID badges, ID bracelets, and many other

objects. Applications include work-in-progress tracking, electronic travelers, access control and storage of

calibration constants.

OVERVIEW

The block diagram in Figure 1 shows the relationships between the major control and memory sections of

the DS1971. The DS1971 has four main data components: 1) 64-bit lasered ROM, 2) 256-bit EEPROM

data memory with scratchpad, 3) 64-bit one-time programmable application register with scratchpad, and

4) 8-bit status memory. The bus master must first provide one of the ROM Function Commands before

the memory functions become accessible. All data is read and written least significant bit first.

The DS1971 contains the same memory chip as the DS2430A. For a full description of the logical

behavior, please refer to the DS2430A data sheet.

DS1971

DS1971 BLOCK DIAGRAM Figure 1

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DS1971

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Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim

reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

The Maxim logo is a registered trademark of Maxim Integrated Products, Inc.

REVISION HISTORY

REVISION

DATE DESCRIPTION PAGES

CHANGED

071508 Updated the F3 MicroCan and F5 MicroCan face brands with the latest

per PCN H020201. 1

7/09 Conversion to lead(Pb)-free; removal of bullet “Designed to meet

UL#913 (4th Edit.)….” 1