A programmable R/W transponder tuned to 125kHz that implements all important functions for identification systems in the industrial and consumer segment. The device allows the contactless reading and writing of data transmitted bi-directionally between a read/write interrogator (reader) and the transponder. The device comes in a plastic package that accommodates the IDIC e5551 and antenna realized as an LC-circuit. The device is a passive RFID device and no additional external power supply is necessary. Data is transmitted by modulating the amplitude of the RF field giving the ASK, FSK and PSK options. Codings schemes implemented are NRZ, Manchester and Bi-Phase. The on-chip 264-bit EEPROM (8 blocks, 33 bits per block) can be read and written by block from the intertogator station.