A CMOS Low Frequency Analog RFID Front-End for the IoT

The design, fabrication and test of a Low Frequency (LF) analog passive front-end for the ISO 11784/11785 and ISO 14223 HDX communication protocols is presented. It has been implemented in the TSMC 90nm CMOS process. The different blocks of the front-end have been implemented in order to allow a straightforward interface with a low power microcontroller. The front-end includes the following main features: 1.2V regulated output voltage, frequency-shift keying (FSK) modulation, amplitude-shift keying (ASK) demodulation, discharge and reset. The tag current consumption during both transmission and reception is kept below 5 μA.