A RFID device having a nonvolatile ferroelectric memory includes an analog block. A power-on reset unit configured to sense a power voltage and output a power sensing signal is included in the analog block. A radio frequency signal sensing unit is configured to sense the level of a detecting signal corresponding to a radio frequency signal received by the antenna of the RFID device and outputs a radio frequency sensing signal. A power-on reset mixer is configured to synthesize the power sensing signal and the radio frequency sensing signal and outputs a power-on reset signal according to the voltage levels of the power sensing signal and the radio frequency sensing signal.