用于125kHz RFID标签芯片的低功耗射频模拟接口  

Low Power Consumption RF Analog Interface for 125 kHz RFID Tag Chips

作　　者：米琦 唐宁[1] 翟江辉[1] 陈永和 刘耀隆 Mi Qi;Tang Ning;Zhai Jianghui;Chen Yonghe;Liu Yaolong(School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学信息与通信学院,广西桂林541004

出　　处：《半导体技术》2022年第11期891-899,共9页Semiconductor Technology

基　　金：广西自然科学基金资助项目(2018GXNSFAA138025);广西科技基地和人才专项资助项目(桂科AD18281037)。

摘　　要：设计了一种用于125 kHz射频识别(RFID)标签芯片的射频模拟接口。通过在NMOSFET栅交叉型整流电路中加入过压保护电路,可在5 ms内将整流电压稳定在6.5 V,发送数据期间自动切断静态电流回路,解决了整流电路额外损耗能量的问题;数据收发采用接收幅移键控(ASK)信号、发送频移键控(FSK)信号的模式,提高了标签芯片的有效读写距离;为解决FSK频率不准导致的误码问题,在电路内部预留了调频(FM)端口,实现了芯片的FSK谐振频率精准可控。仿真结果表明,芯片完成一次读写操作供电电压下降50%,整体功耗342μW,可将数据1和0分别转换成频率为123.5 kHz和136.9 kHz的FSK信号。基于SMIC 0.35μm EEPROM工艺进行了流片验证,模拟电路版图面积为0.34 mm^(2),测试结果表明,芯片可解调125 kHz ASK载波信号,可将数据识别码准确无误地发送给读写器,最长读写距离为9 cm。其低功耗、远距离读写的特性非常适合用于植入式动物标签。A radio frequency analog interface for 125 kHz radio frequency identification(RFID)tag chip was designed.By adding an overvoltage protection circuit to the NMOSFET gate crossover rectifier circuit,the rectifier voltage could be stabilized at 6.5 V within 5 ms,the quiescent current loop was automatically cut off during data transmission,and the problem of additional energy loss in the rectifier circuit was solved.Data receive-transmit adopted the modes of receiving amplitude-shift keying(ASK)signal and sending frequency-shift keying(FSK)signal,which improved the effective reading and writing distance of the tag chip.To solve the problem of bit error caused by the inaccurate FSK frequency,the internal frequency modulation(FM)port was reserved in the circuit to realize the precise and controllable FSK resonant frequency of the chip.Simulation results show that the chip completes a read/write operation with a 50%drop in supply voltage,the total power consumption of 342μW,and the data 1 and 0 can be converted into FSK signals with frequencies of 123.5 kHz and 136.9 kHz respectively.The designed circuit is verified based on SMIC 0.35μm EEPROM process,and the layout area of the analog circuit is 0.34 mm^(2).The test results show that the chip can demodulate the 125 kHz ASK carrier signal,and the data identification code can be transmitted to the reader correctly with a maximum read/write distance of 9 cm.The low-power consumption,long-distance reading and writing characteristics ensure the tag chip especially suitable for implantable animal tags.

关 键 词：射频识别(RFID) 标签芯片 能量采集 低功耗 频移键控(FSK)调制 

分 类 号：TN792[电子电信—电路与系统]