The MFRC523 is a highly integrated reader/writer for contactless communication at 13.56 MHz. The MFRC523 reader supports ISO/IEC 14443 A/MIFARE mode. The MFRC523’s internal transmitter is able to drive a reader/writer antenna designed to  communicate with ISO/IEC 14443 A/MIFARE cards and transponders without additional active circuitry. The receiver module provides a robust and efficient implementation for  demodulating and decoding signals from ISO/IEC 14443 A/MIFARE compatible cards and  transponders. The digital module manages the complete ISO/IEC 14443 A framing and  error detection (parity and CRC) functionality