The MFRC522 is a highly integrated reader/writer IC for contactless communication at 13.56 MHz. The MFRC522 reader supports ISO/IEC 14443 A/MIFARE and NTAG. The MFRC522’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. The MFRC522 supports MF1xxS20, MF1xxS70 and MF1xxS50 products. The MFRC522 supports contactless communication and uses MIFARE higher transfer speeds up to 848 kBd in both directions

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