The DS1982 1Kb Add-Only 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 DS1982 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 (09h) plus 1Kb of EPROM that is user-programmable. The power to program and read the DS1982 is derived entirely from the 1-Wire communication line.
Data is transferred serially via the 1-Wire protocol that requires only a single data lead and a ground return. The entire device can be programmed and then write-protected if desired. Alternatively, the part may be programmed multiple times with new data being appended to, but not overwriting, existing data with each subsequent programming of the device.
Note: Individual bits can be changed only from a logical 1 to a logical 0, never from a logical 0 to a logical 1. A provision is also included for indicating that a certain page or pages of data are no longer valid and have been replaced with new or updated data that is now residing at an alternate page address. This page address redirection allows software to patch data and enhance the flexibility of the device as a standalone database. The 48-bit serial number that is factory-lasered into each DS1982 provides a guaranteed unique identity that 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 DS1982 to be used easily by human operators or automatic equipment. Accessories permit the DS1982 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, storage of calibration constants, and debit tokens.
Special Features
- 1024 bits Electrically Programmable Read-Only Memory (EPROM) communicates with the economy of one signal plus ground
- EPROM partitioned into four 256-bit pages for randomly accessing packetized data
- Each memory page can be permanently writeprotected to prevent tampering
- Device is an “add only” memory where additional data can be programmed into EPROM without disturbing existing data
- Architecture allows software to patch data by superseding an old page in favor of a newly programmed page
- Reduces control, address, data, power, and programming signals to a single data pin
- 8-bit family code specifies DS1982 communications requirements to reader
- 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
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
- Designed to meet UL#913 (4th Edit.); Intrinsically Safe Apparatus, Under Entity Concept for use in Class I, Division 1, Group A, B, C and D Locations, contact Dallas Semiconductor for certification schedule
F5 MicroCAN
