The ATA5567 is a contactless R/W IDentification IC (IDIC) for applications in the 125-kHz frequency range. A single coil, connected to the chip, serves as the IC¡¯s power supply and bi-directional communication interface. The antenna and chip together form a transponder or tag.The on-chip 330-bit EEPROM (10 blocks, 33 bits each) can be read and written block-wise from a reader. Block0 is reserved for setting the operation modes of the ATA5567 tag. Block7 may contain a password to prevent unauthorized writing. Data is transmitted from the IDIC using load modulation. This is achieved by damping the RF field with a resistive load between the two terminals Coil1 and Coil2. The IC receives and decodes 100% amplitude-m odulated (OOK) pulse-interval-encoded bit streams from the base station or reader.