NFC(Near Field Communication)是一种采用 13.56MHz 频带的近距离无线通信技术。结合了感应式读卡器、感应式卡片和点对点功能。虽然通信距离仅为 10cm 左右,不过和非接触式 IC 卡技术一样,“只需碰一下”,便可在不同的电子产品间交换数据。
与非接触式 IC 卡不同之处在于 NFC 可进行双向通信。只要是支持 NFC 的产品和 IC 卡,就可以读出或写入数据。还可在手机等便携产品间进行通信。数据传输速度不高,有 106Kbit/秒、212Kbit/秒、424Kbit/秒以及 848Kbit/秒四种速度可供选择。
NFC 三种工作模式
1、 NFC 方案框图
2、NFC 方案特点
2.1.1 NXP PN544/PN65O(pin to pin,PN65O Embedded Secure Element)
2.1.2 NXP PN547/PN65T(pin to pin,PN65T Embedded Secure Element)
2.1.3 NXP NPC100
◦Card Emulation
ISO/IEC 14443 (A&B), MIFARE and Type B’ card emulation support via SWP up to 424Kbit/s
ISO/IEC 14443A,MIFARE over NFC-WI
◦Reader/Writer mode
ISO/IEC 14443 Type A & B R/W up to 848 Kbit/s
ISO/IEC 15693
FeliCa R/W support up to 424Kbit/s
Support of all mandatory NFC Forum tags types
R/W support for MIFARE 1K,4K
◦Peer to Peer mode
NFCIP-1 compliance(PN544)
NFCIP-1 & NFCIP-2 compliance(PN547)
◦Features
80C51(PN544),Cortex M0 core (NPC100/PN547)
Automated Rx gain control / Diff Rx path
Integrated power management unit
Hard power down mode
Direct connection to mobile battery 2.3 to 5.5V
Powered-by-the-field in card emulation
Secure element supply (SIM,SmartMX)
Integrated FracNpll to save Xtal quartz
Integrated self test to test antenna matching circuit during production
◦Interfaces
Host baseband:SPI,I2C,Serial UART
Secure element:SWP,NFC-WI
2.2 TI TRF7970A
Supports Near Field Communication (NFC) Standards NFCIP-1 (ISO/IEC 18092) and NFCIP-2 (ISO/IEC 21481)
Completely Integrated Protocol Handling for ISO15693,ISO18000-3,ISO14443A/B and FeliCa
Integrated Encoders,Decoders and Data Framing for NFC Initiator,Active and Passive Target Operation for All Three Bit Rates (106 Kbps,212 Kbps,424 Kbps) and Card Emulation
RF Field Detector with Programmable Wake-Up Levels for NFC Passive Transponder Emulation Operation
RF Field Detector for NFC Physical Collision Avoidance
Integrated State Machine for ISO14443A Anti-collision (Broken Bytes) Operation (Transponder Emulation or NFC Passive Target)