Description:
The TM1990A is a rugged data carrier that serves as an electronic 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 TM1990A 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 TM1990A to be used easily by human operators.

 
Key Features:
Can Be Read in Less Than 5ms
Operating Range: 2.8V to 6.0V, -40°C to +85°C
Common iButton Features
Unique 64-Bit Registration Number Ensures Error-Free Device Selection and Absolute Traceability Because No Two Parts are Alike
Built-In Multidrop Controller for 1-Wire Net
Digital Identification by Momentary Contact
Data Can Be Accessed While Affixed to Object
Economically Communicates to Bus Master with a Single Digital Signal at 16.3kbps
Button Shape is Self-Aligning with Cup-Shaped Probes
Durable Stainless-Steel Case 
Easily Affixed with Self-Stick Adhesive Backing, Latched by its Flange, or Locked with a Ring Pressed Onto its Rim
When the electric key is put to the key-reader, a signal is sent. The electric key reader can be connected to a 1-Wire device