The DS1990A serial number iButton is a rugged data carrier that can be used as an electronic registration number for automatic identification systems. Each DS1990A contains a factory-programmed unique 64-bit registration number for absolute traceability. It has a working range of 2.8V to 6.0V and a read time of less than 5ms.
The DS1990A iButton is a rugged stainless‑steel serial number carrier that stores a factory‑programmed unique 64‑bit registration number. It communicates over a single‑wire (1‑Wire) bus, requiring only one signal line and ground, and is suitable for access control, inventory, and tool management applications.
The document provides physical dimensions, electrical characteristics, timing diagrams, and command descriptions for using the device on a 1‑Wire network, including ROM functions such as Read ROM and Search ROM. This manual is written in Chinese.
| Weight | ≈ 2.5 g |
|---|---|
| Operating Voltage | 2.8 V – 6.0 V |
| Storage Temperature | -55 °C to +125 °C |
| IO Current | 20 mA |
| Data Rate | up to 16.3 kbps |
| Typical Pull‑up Resistor | 2.2 kΩ |
Each DS1990A includes a factory‑programmed unique 64‑bit registration number.
The ROM code is 64 bits long, consisting of an 8‑bit family code, a 48‑bit serial number, and an 8‑bit CRC.
The device can transmit data at up to 16.3 kbps over the 1‑Wire bus.
A 2.2 kΩ pull‑up resistor is commonly used for most applications.