MAXIM DS1985-F5+

The DS1985 16Kb Add-Only iButton is a rugged read/write data carrier used to identify and store information associated with the person or object to which it is attached. This information can be accessed with minimal hardware, such as a single port pin of a microcontroller. The DS1985 contains a factory laser-programmed registration number that includes a unique 48-bit serial number, an 8-bit CRC, and an 8-bit family code (0BH), plus 16Kb of user-programmable EPROM. The power required to program and read the DS1985 is derived entirely from the 1-Wire communication line. Data is transferred serially via the 1-Wire protocol, which requires only a single data line and a ground return. The entire device can be programmed as needed and subsequently write-protected. Alternatively, the device can be programmed multiple times, with each subsequent programming session appending new data after the existing data rather than overwriting it. Note: Individual bits can only be changed from logic 1 to logic 0, never from logic 0 to logic 1. The device also includes a feature to indicate that certain data pages are no longer valid and have been replaced by new or updated data located at alternate page addresses. This page address redirection feature allows software patching of data and enhances the device's flexibility as a stand-alone database. The 48-bit serial number factory laser-programmed into each DS1985 provides guaranteed unique identification for absolute traceability. The rugged MicroCan package is highly resistant to harsh environments including dust, moisture, and shock. Its compact button-shaped profile self-aligns with cup-shaped sockets, enabling easy use of the DS1985 by operators or automated equipment. Companion accessories allow the DS1985 to be mounted on PCBs, plastic key fobs, photo ID cards, ID wristbands, and many other objects.

• 16384-bit EPROM, requiring only a single signal line and ground for cost-effective communication
• EPROM organized into 64 pages of 256 bits for random access of grouped data records
• Each memory page permanently write-protectable against tampering
• "Append-only" memory architecture — additional data can be programmed into EPROM without disturbing existing data
• Architecture allows software to patch data by replacing old pages with newly programmed ones
• Control, address, data, power, and programming signals reduced to a single data pin
• 8-bit family code specifies DS1985 communication requirements to the reader
• Read voltage range 2.8 V ~ 6.0 V over -40°C to +85°C; programming voltage 11.5 V ~ 12.0 V over -40°C to +85°C
• Factory laser-engraved and tested 64-bit registration number ensures traceability — no two devices are identical
• Multipoint controller for MicroLAN
• Digital identification and data transfer via momentary contact
• Chip-based data carrier for compact information storage
• Data accessible while attached to object
• Cost-effective single digital signal communication with bus master at 16.3 kbps
• Standard 16mm diameter and 1-Wire protocol ensure compatibility with iButton family
• Button shape self-aligns with cup-shaped probes
• Durable stainless steel case laser-engraved with registration number, withstands harsh environments
• Easy attachment via self-adhesive backing, flange latch, or lock ring pressed against edge
• Presence detector confirms upon first application of voltage by reader