iButton key TM1990 card with magnetic ring / DS1990A magnetic ibutton

Detail product Description:

Product Name: iButton TM1990 smart card with magnetic ring
Product Model: TM1990A-F5
Product Group: smart card--ibutton card/TM Smart Card

Features:
-with magnetic ring special use
-Upgrade of DS1990 allows multiple Serial Number
-304-0.3 stainless steel package, durable, never rust and corrosion; resistance to heat; resistant variants
-can be read under water.
-Unique 64bit serial number,2401 chips,used universal.
-Low-cost electronic key for access control
-8-bit CRC for checking data integrity
-Can be read in less than 5 ms
-Operating temperature range of -40°C to +85°C
-Chip-based data carrier compactly stores information.

Introduction of Ibutton card(TM1990 Card)
TM cards (commonly known as Pengpeng card or Button card, also known as iB card (iB is the abbreviation for iButton)) is a patented product of DALLAS Inc., U. S., which communicates with the reader through single line protocol and data read-writes are completed through an instant touch. The card is not only provided with operability of Contactless IC card, but also possesses low cost of Contact IC card, and is one of the best IC cards that has a fairly high cost performance.

The basic principles of Ibutton card(TM1990 Card):
-A TM card is similar to a button battery in shape and can be inlaid into a card, key button and other objects.
You can replace the data line, address line, control line and power line with a single line so that TM card achieves single line communication through a multi-function device. When the host is powered, TM card gives the response to the host through switching the impedances between 50Ω And 500, 000Ω . The lengths of time the signal is pulled down(long or short) show the digital logics(long=1, short=0). Due to the range of witching impedances is 1-10, 000, the resistances of the contact points will not affect the identification of the digital signals.
-According to whether the Memory in TM card is encrypted or not, TM card can be divided into encrypted TM card and non-encrypted TM card.
-Most of TM cards are non-encrypted.