The EM4205/4305 is a CMOS integrated circuit intended for use in electronic Read/Write RF transponders. It is suitable for low-cost solutions like animal tagging applications. The IC communication protocol is compatible with the EM4469/4569 family.
The IC reads out data from its internal EEPROM and sends it out by switching on and off a resistive load in parallel to the coil using a large modulation index. Commands and EEPROM data updates can be executed by 100% AM modulation of the 125 kHz magnetic field.
The EM4205/4305 supports several Bi-phase and Manchester data encodings.
The operating modes are stored in the EEPROM configuration word. All EEPROM words can be write-protected by setting protection bits. The IC contains a factory programmed 32 bit UID number.