【导读】 随着移动支付浪潮的兴起，NFC 近场通信技术受到银行和运营商的力挺。另一方面，拥有 375Mbps传输数据率的 TransferJet 近场通信技术也在逐渐成为大数据高速传输技术的新宠。为应对这两大市场趋势，世平集团特推出 NFC 和 TransferJet 近场通信技术方案。
一、NFC近场通信技术方案
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. NXP 方案框图
2. NFC 芯片特点
2.1 NXP PN544/PN65O PN547/NPC100/PN65T
•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
•Features
◦80C51(PN544PC), Cortex M0 core (NPC100)
◦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
◦Package
■PN544PC TFBG (4.5x4.5x0.8mm)
■NPC100 VFBGA64 (4.0x4.3x0.9mm), WLCSP
•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)
•Input Voltage Range: 2.7 VDC to 5.5 VDC
•Programmable Output Power: +20 dBm (100 mW), +23 dBm (200 mW)
•Programmable I/O Voltage Levels From 1.8 VDC to 5.5 VDC
•Programmable System Clock Frequency Output (RF，RF/2，RF/4) from 13.56 MHz or 27.12 MHz Crystal or Oscillator
•Integrated Voltage Regulator Output for Other System Components (MCU，Peripherals，Indicators)，20 mA (Max)
•Programmable Modulation Depth
•Dual Receiver Architecture with RSSI for Elimination of "Read Holes" and Adjacent Reader System or Ambient In-Band Noise Detection
•Programmable Power Modes for Ultra Low-Power System Design (Power Down <1 µA)
•Parallel or SPI Interface (With 127 Byte FIFO)
•Temperature Range: –40°C to 110°C
•32 Pin QFN Package (5 mm x 5 mm)
3. NFC 方案照片
•NXP PN544/PN65O EVM
•NXP PN547/PN65T EVM
•NXP NPC100 EVM
•TI TRF7970A EVM
二、TransferJet 近场通信技术方案
这是一种类似 NFC 的近场无线技术，可以让两个数码产品在 3cm 的距离内进行数据高速传输——375Mbps，最大值甚至高达 560Mbps，建立连接的时间只有 0.1 秒，且低功耗。如果有两个这样的接触头，那么一碰之间就可以连接通。和 NFC 不同在于 TransferJet 一开始就采用的是 4.48GHz 的高频载波，是为高速、大文件和大数据量传输的应用场合而设计的。
1. 方案框图
2. 方案特点
•TransferJet Specification compliant
•Output frequency 4.48GHz
•Transmit Output：up to-42.5dBm
•Transfer speed：522Mbps(max.)
•External reference clock：20MHz/40MHz(Xtal)
•Host Interface：SDIO Device I/F(High Speed UHS-I supports)
•SPI for Memory Interface：EEPROM
•Power Supply Management Unit(PMU)
•10KHz CR oscillator
•Low power consumption operation
•Low power mode support
•Power Supply Voltage
•Single Power Supply operation：1.8V
•Double Power Supply operation：1.8V/3.3V
3. 方案照片
•Spreadtrum 手机实现 TransferJet 功能
•Rockchip 平板实现 TransferJet 功能
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