iButton™ (DS1990A-F3+)

Description: The DS1990A Serial Number iButton is a rugged data carrier that acts as an electronic registration number for automatic identification. The DS1990A consists of a factory-lasered, 64-bit ROM that includes an unique 48-bit serial number, an 8-bit CRC and an 8-bit Family Code (01h). Data is transferred serially via the 1-Wire protocol which requires only a single data lead and a ground return. The DS1990A is fully compatible with the DS1990 Serial Number iButton but provides the additional 1-Wire protocol capability that allows the Search ROM command to be interpreted by the DS1990A and therefore allows multiple DS1990A devices to reside on a single data line.

The durable MicroCan package is highly resistant to environmental hazards such as dirt, moisture and shock. Its compact coin-shaped profile is self-aligning with mating receptacles, allowing the DS1990A to be used easily by human operators. Accessories permit the DS1990A to be mounted on plastic key tabs, photo ID badges, printed circuit boards or any smooth surface of an object. Applications include access control, work-in-progress tracking, tool management and inventory control.

Features:

• Upgrade of DS1990 allows multiple Serial Number iButtons to reside on a common bus
• Unique 48–bit serial number
• Low-cost electronic key for access control
• 8-bit CRC for checking data integrity
• Can be read in less than 5 ms
• Operating temperature range of -40°C to +85°C