The U3280M is a transponder interface for use in contactless ID systems, remote control systems, tag and sensor applications. It supplies the microcontroller with power from an RF field via an LC-resonant circuit and it enables contactless bi-directional data communication via this RF field. It includes power management that handles switching between the magnetic field and a battery power supply. To store permanent data like an identifier code and configuration data, the U3280M includes a 512-bit EEPROM with a serial interface. Figure 1. Block Diagram