64 bit  Low-cost rfid 125KHz EM4100/TK4100 proximity id card
-Several options of data rate and coding available
-On chip resonance capacitor
-On chip supply buffer capacitor
-On chip voltage limiter
-Full wave rectifier on chip
-Large modulation depth due to a low impedance modulation device
-Operating frequency 100 – 150 kHz, ( Low-cost rfid 125KHz EM4100/TK4100 proximity id card )
-Very small chip size convenient for implantation
-Very low power consumption
Applications:
-Logistics automation
-Anticounterfeiting
-Access control
-Industrial transponder
-Door control system,
-Identity resolution.       http://www.smacarte.com