Product_description: ["DS1990 Series 6 V 1-Wire Smart Card Interface IC - Microcan-F3 ***** For more information refer to the specification sheet located in the 'Downloads' section below the image *****", 'The DS1990A-F3+ Serial Number iButton is a rugged data carrier that acts as an electronic registration number for automatic identification. The DS1990A-F3+ 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-F3+ is fully compatible with the DS1990-F3+ Serial Number iButton but provides the additional 1-Wire protocol capability that allows the Search ROM command to be interpreted by the DS1990A-F3+ and therefore allows multiple DS1990A-F3+ 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-F3+ to be used easily by human operators. Accessories permit the DS1990A-F3+ 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.'] (Page 1)