原标题：NXP MFRC522 13.56 MHz RFID无接触读写方案

　　nxp公司的MFRC522 是13.56 MHz 无接触通信的高度集成的读/写IC,支持ISO/IEC 14443 A/MIFARE模式,两个方向的传输速率高达848 kBd. MFRC522工作电压2.5V到3.3V,提供SPI,串行UART和I2C总线接口,具有CRC协处理器和可编程I/O引脚,内部有自测试.本文介绍MFRC522主要特性, 简化和详细方框图, 读/写模式, 总线接口图以及典型应用方框图.

　　MFRC522: Contactless reader IC

　　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 mode.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 following host interfaces are provided:

　　• Serial Peripheral Interface (SPI)

　　• Serial UART (similar to RS232 with voltage levels dependant on pin voltage supply)

　　• I2C-bus interface

　　MFRC522主要特性:

　　Highly integrated analog circuitry to demodulate and decode responses

　　Buffered output drivers for connecting an antenna with the minimum number of external components

　　Supports ISO/IEC 14443 A/MIFARE

　　Typical operating distance in Read/Write mode up to 50 mm depending on the antenna size and tuning

　　Supports MF1xxS20, MF1xxS70 and MF1xxS50 encryption in Read/Write mode

　　Supports ISO/IEC 14443 A higher transfer speed communication up to 848 kBd

　　Supports MFIN/MFOUT

　　Additional internal power supply to the smart card IC connected via MFIN/MFOUT

　　Supported host interfaces

　　SPI up to 10 Mbit/s

　　I2C-bus interface up to 400 kBd in Fast mode, up to 3400 kBd in High-speed mode

　　RS232 Serial UART up to 1228.8 kBd, with voltage levels dependant on pin voltage supply

　　FIFO buffer handles 64 byte send and receive

　　Flexible interrupt modes

　　Hard reset with low power function

　　Power-down by software mode

　　Programmable timer

　　Internal oscillator for connection to 27.12 MHz quartz crystal

　　2.5 V to 3.3 V power supply

　　CRC coprocessor

　　Programmable I/O pins

　　Internal self-test

　　图1.MFRC522简化方框图

　　图2.MFRC522详细方框图

　　图3.MFRC522读/写模式

　　图4.MFRC522 I2C总线接口图

　　图5.MFIN和MFOUT信号路经图

　　图6.MFRC522典型应用方框图