19-4889 Rev 8/09 DS1973 4Kb EEPROM iButton SPECIAL FEATURES COMMON iButton FEATURES 4096 bits Electrically Erasable Programmable Unique, factory-lasered and tested 64-bit Read Only Memory (EEPROM) registration number (8-bit family code + Overdrive mode boosts communication speed 48-bit serial number + 8-bit CRC tester) to 142kbps assures absolute identity because no two 256-bit scratchpad ensures integrity of data parts are alike transfer Multidrop controller for MicroLAN Memory partitioned into 256-bit pages for Digital identification and information by packetizing data momentary contact Reduces control, address, data and power to a Chip-based data carrier compactly stores single data pin information 8-bit family code specifies DS1973 Data can be accessed while affixed to object communication requirements to reader Economically communicates to bus master Reads and writes over a wide voltage range of with a single digital signal at 16.3kbps 2.8V to 6.0V from -40C to +85C Standard 16mm diameter and 1-Wire protocol ensure compatibility with iButton F3 MicroCan 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 F5 MicroCan PART PIN-PACKAGE DS1973-F3+ F3 MicroCan DS1973-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 DS9093A Snap-In Fob DS9092 iButton Probe iButton and 1-Wire are registered trademarks of Maxim Integrated Products, Inc. 1 of 3 DS1973 iButton DESCRIPTION The DS1973 4Kb 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 micro-controller. The DS1973 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 (23H) plus 4096 bits of EEPROM. The power to program and read the DS1973 is derived entirely from the 1-Wire communication line. The memory is organized as sixteen pages of 256 bits each. The 64-bit registration number provides a guaranteed unique identity which allows for absolute traceability. Data is transferred serially via the 1-Wire protocol which requires only a single data lead and a ground return. 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 DS1973 to be used easily by human operators or automatic equipment. Accessories permit the DS1973 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 DS1973. The DS1973 has three main data components: 1) 64-bit lasered ROM, 2) 256-bit scratchpad, and 3) 4096-bit EEPROM. 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 DS1973 contains the same memory chip as the DS2433. For a full description of the logical behavior, please refer to the DS2433 data sheet. DS1973 BLOCK DIAGRAM Figure 1 2 of 3