Overview
The DS1990A serial number iButton® is a rugged data carrier that serves as an electron- ic registration number for automatic identification. Data is transferred serially through the 1-Wire® protocol, which requires only a single data lead and a ground return. Every DS1990A is factory lasered with a guaranteed unique 64-bit registration number that allows for absolute traceability. The durable stainless-steel iButton 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 enable the DS1990A iButton to be mounted on almost any object, including containers, pallets, and bags.
Absolute maximum Rating
IO Voltage Range to GND..............................................................................V to +6.0V
Junction Temperature..............................................................................125°C
IO Sink Current..............................................................................20mA
Storage Temperature Range..............................................................................-55°C to +125°C
Technical Specifications
| PARAMETER | MIN | TYP | MAX | UNITS |
| 1 -Wire Pull-up Voltage | 2.8 | V | ||
| 1 -Wire Pull-up Resistance | 0.6 | k | ||
| Input Capacitance | 2.8 | 100 | pF | |
| Input Load Current | 0.25 | pA | ||
| Input Low Voltaqe | 0.3 | V | ||
| Input High Voltage | 2.2 | V | ||
| Output Low Voltage at 4mA | 0.4 | V | ||
| Operating Charge | 30 | nC | ||
| Recovery Time | 1 | }JS | ||
| Time Slot Duration | 61 | }JS |