iButton Tag
iButton Dallas DS1990A
Rugged Data Carrier with 1-Wire® Protocol for Automatic Identification

Rugged Design
Highly resistant to environmental hazards such as dirt, moisture, and shock
Unique Identification
Factory lasered with guaranteed unique 64-bit registration number
1-Wire Protocol
Serial data transfer through single data lead and ground return
Compact Form Factor
Coin-shaped profile: 8.7mm radius, 3.1mm width for easy handling
Wide Temperature Range
Operates in extreme temperatures from -40°C to +85°C
RoHS Compliant
Lead-free and environmentally compliant package options
Specification
| Physical Specifications | |
| Radius | 8.7 mm |
| Width/Height | 3.1 mm |
| Package Material | Durable stainless steel |
| Electrical Specifications | |
| Read Time | 5 ms |
| Read/Write Voltage | 2.8V – 6.0V DC |
| Communication Protocol | 1-Wire® |
| Communication Speed | 16.3 kbps |
| Environmental Specifications | |
| Working Temperature | -40°C ~ +85°C |
| Environmental Resistance | Dirt, moisture, and shock resistant |
| Data Specifications | |
| Registration Number | 64-bit unique serial number |
| Family Code | First 8 bits (1-Wire family code) |
| Unique Serial Number | Next 48 bits |
| CRC Code | Last 8 bits |
| Product Variants | |
| DS1990A-F5+ | F5 iButton variant, Lead-free/RoHS-compliant |
| DS1990A-F3+ | F3 iButton variant, Lead-free/RoHS-compliant |
Applications
- Automatic identification systems
- Electronic registration number tracking
- Container and pallet identification
- Asset management and tracking
- Access control systems
- Industrial automation