Introduction
This document describes the functionality of the contactless reader/writer MFRC522. It includes the functional and electrical specifications.

General description
The MFRC522 is a highly integrated reader/writer for contactless communication at 13.56 MHz. The MFRC522 reader supports ISO 14443A / MIFARE® mode.
The MFRC522’s internal transmitter part is able to drive a reader/writer antenna designed to communicate with ISO/IEC 14443A/MIFARE® cards and transponders without additional active circuitry. The receiver part provides a robust and efficient implementation of a demodulation and decoding circuitry for signals from ISO/IEC 14443A/MIFARE® compatible cards and transponders. The digital part handles the complete ISO/IEC 14443A framing and error detection (Parity & CRC).The MFRC522 supports MIFARE®Classic (e.g. MIFARE® Standard) products. The MFRC522 supports contactless communication using MIFARE® higher transfer speeds up to 848 kbit/s in both directions.

Various host interfaces are implemented:
• SPI interface
• serial UART (similar to RS232 with voltage levels according pad voltage supply)
• I2C interface.

FEATUREs
■ Highly integrated analog circuitry to demodulate and decode responses
■ Buffered output drivers to connect an antenna with minimum number of external
   components
■ Supports ISO/IEC 14443A / MIFARE®
■ Typical operating distance in Reader/Writer mode for communication to a
   ISO/IEC 14443A / MIFARE® up to 50 mm depending on the antenna size and tuning
■ Supports MIFARE® Classic encryption in Reader/Writer mode
■ Supports ISO/IEC 14443A higher transfer speed communication up to 848 kbit/s
■ Support of the MFIN / MFOUT
■ Additional power supply to directly supply the smart card IC connected via MFIN /
   MFOUT
■ Supported host interfaces
   ◆ SPI interface up to 10 Mbit/s
   ◆ I2C interface up to 400 kbit/s in Fast mode, up to 3400 kbit/s in High-speed mode
   ◆ serial UART in different transfer speeds up to 1228.8 kbit/s, framing according to
      the RS232 interface with voltage levels according pad voltage supply
■ Comfortable 64 byte send and receive FIFO-buffer
■ Flexible interrupt modes
■ Hard reset with low power function
■ Power-down mode per software
■ Programmable timer
■ Internal oscillator to connect 27.12 MHz quartz
■ 2.5 - 3.3 V power supply
■ CRC Co-processor
■ Free programmable I/O pins
■ Internal self test