基于电流模式的ASK解调器

设计了一种工作在电流模式下的ASK解调器,电路首先将电压信号转换为电流信号,并对电流信号进行延时,然后将延时电流与原始电流进行比较,获取信号的边沿位置,最后用RS触发器还原出最终数据。该解调器可以在一个比较宽的供电电压范围内解调出深度更浅的ASK信号,可以应用到不同标准的RFID标签中,而且电路受工艺变化的影响非常低。电路采用HHNEC 0.35μm5 V CMOS工艺设计,仿真结果表明,供电电压在2.6~5 V之间,在此电压范围内解调器至少可以解调深度为5%的ASK信号。     

锁相环频率合成器中的电荷泵设计

用TSMC 0.18μm CMOS工艺设计了一种电荷泵电路。传统的电荷泵电路中充放电电流有较大的电流失配,文章采用与电源无关的基准电流源电路,运用运算放大器和自偏置高摆幅共源共栅电流镜电路实现了充放电电流的高度匹配。仿真结果表明:电源电压1.8V时,电荷泵电流为0.5mA;在0.3V～1.6V输出电压范围内电流失配小于1μA,功耗为6.8mW。     

一种应用于锁相环的增益提高型电荷泵设计

采用0.18μm 1.8V CMOS工艺设计一种增益提高型电荷泵电路,利用增益提高技术和折叠式共源共栅电路实现充放电电流的匹配.该电荷泵结构可以很大程度地减小沟道长度调制效应的影响,使充放电电流在宽输出电压范围内实现精确匹配,同时具有结构简单的优点.仿真结果表明,电源电压1.8V时,电荷泵电流为600μA,在0.3～1.6V输出范围内电流失配为0.6μA,功耗为3mW.     

一种新型低电压极限电流检测电路

为磁滞电流控制的DC-DC开关稳压器设计了一种新型的极限电流检测器。该电路不借助于专门的电流检测电路,只使用一个检测MOSFET和一个电压比较器来实现极限电流检测,减小了电路的复杂度。针对电流检测器的要求,设计了一种低电源电压、高共模电压的比较器。使用TSMC 0.18μm CMOS混合信号工艺,对电路进行设计。结果表明,电路具有很好的容差特性,并且电路可工作在1.2 V的低电源电压下。     

一种新型的宽线性范围差分电压输入电流传输器及其应用

设计了一种带有共模检测电路的宽线性范围差分电压输入电流传输器(DVCCⅡ).所提出的电路具有动态的长尾电流的差分对,可获得较大的动态线性输入范围.所提出的电路可以得到精确跟随特性和宽线性输入范围,且比较已有电路具有低电压低功耗等特点.采用SMIC 0.18μm工艺,用Spectre对电路进行仿真,电源电压是1.8 V,...     

低杂散锁相环中的电荷泵设计

用TSMC 0.18μm CMOS工艺设计并实现了一种电荷泵电路.传统的电荷泵电路中充放电电流有较大的电流失配,电流失配导致相位偏差,从而引起杂散并降低了锁相环的锁定范围.文中采用与电源无关的基准电流源电路,运用运算放大器和自偏置高摆幅共源共栅电流镜电路实现了充放电电流的高度匹配,从而降低了杂散.测试结果表明:电源电压1.8V时,电荷泵电流为0.475mA,在0.3～1.6V输出电压范围内电流失配小于10mA,功耗为6.8mW.     

一种高速高分辨率电流舵D/A转换器的设计

基于0.18μm CMOS工艺,设计了一种电源电压为3.3 V/1.8 V(模拟电路部分电源电压为3.3 V,数字电路部分电源电压为1.8 V)、最大刷新率为200 MSPS、分辨率为14位的高速D/A转换器(DAC).该DAC采用传统的5-4-5温度计码与二进制权重码混合编码的分段电流舵结构.对电路中的关键模块,如运算放大器、带隙基准源,进行了优化设计;给出了整体电路的版图设计.仿真结果显示,采样频率为200 MHz时,DAC的SFDR为87 dB左右.     

宽电源范围的高精度振荡器设计技术研究

为解决CMOS振荡器频率稳定性差的问题,提出一种基于阈值电压的高精度宽电源范围振荡器电路结构。利用与电源无关的恒流源和MOS管开通关断对电容进行充放电,产生占空比50%的时钟信号,设计熔丝电阻控制可修调电流镜电路实现工艺修调。基于0.25μm BCD工艺,对提出的方法进行了具体电路设计与物理实现验证,结果表明：在电源电压3 V典型情况下,时钟信号中心频率为36.5 kHz,工艺修调范围为54.14%～219.18%,修调精度为-0.82%～+2.53%。电源电压2～4 V变化范围内,频率变化系数为0.97%/V;电源电压1.8～5.8 V变化范围内,频率变化系数为2.47%/V;电源电压在1.8～12 V范围内,频率变化系数为1%/V,具有较宽的电源适应特性。     

一种新颖的快速启动零温度系数电流基准

基于三极管BE结电压的负温度特性原理,提出了一种零温度系数电流基准电路.该电路具有结构简单、无需带隙基准单元、静态功耗低、启动快速、对电源电压不敏感等优点,实用性高.在0.5 μm标准CMOS工艺下,Hspice模拟结果显示,在25℃、1.8～5.5 V范围内,基准电流变化0.019μA;在1.8 V、-40℃～125℃范围内,基准电流变化0.09μA.该新方案可用于无需电压基准、低功耗、需要快速启动的混合信号系统设计.     

一种高精度高稳定性锯齿波振荡器的设计

设计了一种应用于DC/DC开关电源管理芯片的锯齿波振荡器,该电路利用内部基准电流源产生的电流对电容进行充放电,使得产生的锯齿波信号随电源电压和温度的变化较小,采用迟滞技术提高了锯齿波信号幅值.采用基于CSMC的0.5μmCMOS 工艺进行仿真.结果表明,该电路产生的振荡频率为5MHz,信号幅值为0-3V,电源电压在2....     

A fully integrated analog front-end circuit for 13.56 MHz passive RFID tags in conformance with ISO/IEC 18000-3 protocol

A fully integrated analog front-end circuit for 13.56 MHz passive RFID tags is presented in this paper. The design of the RF analog front-end and digital control is based on ISO/IEC 18000-3 MODE 1 protocol. This paper mainly focuses on RF analog front-end circuits. In order to supply voltage for the whole tag chip, a high efficiency power management circuit with a rather wide input range is proposed by utilizing 15.5 V high voltage MOS transistors. Furthermore, a high sensitivity, low power consumption 10% ASK demodulator with a subthreshold-mode hysteresis comparator is introduced for reader-to-tag communication. The tag chip is fabricated in 0.18-μm 2-poly 5-metal mixed signal CMOS technology with EEPROM process. An on-chip 1 kb EEPROM is used to support tag identification, data writing and reading. The core size of the analog front-end is only 0.94×0.84 mm² with a power consumption of 0.42 mW. Measured results show that the power management circuit is able to maintain a proper working condition with an input antenna voltage range of 5.82–12.3 V; the maximum voltage conversion ratio of the rectifier reaches 65.92% when the tag antenna voltage is 9.42 V. Moreover, the power consumption of the 10% ASK demodulator is only 690.25 nW.     

集成高效率电荷泵的无源电子标签芯片射频前端设计

提出了一种满足ISO/IEC18000-6C标准的无源超高频RFID(射频识别)标签芯片的射频前端结构,该结构包括高效率电荷泵、解调器、调制器、阻抗匹配网络和ESD保护电路。电荷泵通过阈值补偿原理及精确控制补偿电压有效抑制反向漏电流,消除了传统电荷泵中的阈值损失。芯片经TSMC0.18μm CMOS mixed signal工艺流片,实测结果表明,标签最远读距离达7m,写距离为3m,可应用于识别与定位,同时满足HBM2 000V的抗静电指标。     

基于EPC Class0协议无源电子标签射频前端设计

分析了RFID系统的组成和基本原理,针对超高频EPC Class0协议,提出电子标签前端结构及参考电路,包括整流器、稳压源、能量开启、脉宽解调、反向调制、振荡器、时钟校准等部分。采用Chartered 0.35μm CMOS工艺进行流片,整个前端模块工作电压(不包括整流电路)3.3V,电流13.8μA。最后给出芯片照片及测试结果。     

A low power, low noise figure quadrature demodulator for a 60 GHz receiver in 65-nm CMOS technology

This paper presents the design of a low power (LP) and a low noise figure (NF) quadrature demodulator with an on-chip frequency divider for quadrature local oscillator (LO) signal generation. The transconductance stage of the mixer is implemented by an AC-coupled self-bias current reuse topology. On-chip series inductors are employed at the gate terminals of the differential input transconductance stage to improve the voltage gain by enhancing the effective transconductance. The chip is implemented in 65-nm LP CMOS technology. The demodulator is designed for an input radio frequency (RF) band ranging from 10.25 to 13.75 GHz. A fixed LO frequency of 12 GHz down-converts the RF band to an intermediate frequency (IF) band ranging from DC to 1.75 GHz. From 10 MHz to 1.75 GHz the demodulator achieves a voltage conversion gain (VCG) ranging from 14.2 to 13.2 dB, and a minimum single-sideband NF (SSB-NF) of 9 dB. The measured third-order input intercept point (IIP₃) is -3.3 dBm for a two-tone test frequency spacing of 1 MHz. The mixer alone draws a current of only 2.5 mA, whereas the complete demodulator draws a current of 7.18 mA from a 1.2 V supply. The measurement results for a frequency divider, which was fabricated individually, prior to being integrated with the quadrature demodulator, in 65-nm LP CMOS technology, are also presented in this paper.     

一种高性能CMOS单片中频接收机

研制了一种CM O S低压低功耗中频接收机芯片,它包含混频器、限幅放大器、解调器以及场强指示、消音控制等模块,可用于短距离的FM/FSK信号的接收和解调。该接收机采用1st s ilicon 0.25μm CM O S工艺,芯片的测试结果表明整机接收灵敏度为-103 dBm,最高输入射频频率可以达到100 MH z,解调器的线性解调范围为±10 kH z,典型鉴频灵敏度为40 mV/kH z,输入FM信号(调频指数3,信号频率1 kH z)时解调信号的SFDR为41.3 dB。芯片的工作电源电压范围为2~4 V,工作电流3 mA,有效面积0.25 mm2。     

带新解调结构的UHF RFID标签低功耗模拟前端设计

基于ISO/IEC 18000-6C协议,对UHF无源电子标签模拟前端中的ASK解调电路、整流器、稳压电路等进行低功耗设计。解调电路中微分电路的加入扩大了解调电路工作范围,在解调电路近距离工作时,可以更有效地解调。整流电路采用了零阈值MOS管代替肖特基二极管,降低芯片成本。整流稳压电路可稳定地为芯片供电,供电电压2 V,建立时间仅为25μs。电路采用SMIC 0.18μm 2P4M CMOS工艺进行流片,芯片面积720μm×390μm。测试得到模拟前端整体工作电流仅2.4μA,标签工作距离大于7 m。     

Remotely powered PPM demodulator by inductive coupling for rodent applications

A low-power pulse position modulation (PPM) demodulator has been developed for remotely powered batteryless implantable devices. The required power for the implantable device is provided by the magnetic coupling with the external array of powering of coils placed under the living space of the animal. The remote powering is turned off 6 % of one bit duration during data transmission. The remote powering link is optimized to deliver power at 13.56 MHz frequency. The power is transferred from 30 mm distance with 21 % efficiency. An integrated full-wave rectifier and voltage regulator generate 1.8 V supply voltage from induced signal. The integrated PPM demodulator consumes only 27.8 µW and has 8.33 kb/s data rate. The presented entire system and basic blocks are integrated using a 0.18 µm CMOS technology. Experimental results verify the effectiveness of the PPM demodulator and the downlink communication system.     

A current-mode voltage regulator with an embedded sub-threshold reference for a passive UHF RFID transponder

This paper presents a current-mode voltage regulator for a passive UHF RFID transponder.The passive tag power is extracted from RF energy through the RF-to-DC rectifier.Due to huge variations of the incoming RF power,the rectifier output voltage should be regulated to achieve a stable power supply.By accurately controlling the current flowing into the load with an embedded sub-threshold reference,the regulated voltage varies in a range of 1-1.3 V from-20 to 80 ℃,and a bandwidth of about 100 kHz is achieved for a fast power recovery.The circuit is fabricated in UMC0.18μm mixed-mode CMOS technology,and the current consumption is only 1 μA.     

无源RFID应答器的改进电荷泵设计

提出了一种适用于ISO/IEC 18000-6C标准的无源RFID(射频识别)应答器的改进电荷泵.该设计基于导通角的概念分析能量转化效率.整个结构包含主电荷泵和偏置电路,通过二极管连接的MOS管抑制负载来提升偏置电压,并调节偏置电压有效抑制反向漏电流,消除了传统电荷泵中的阈值损失.该电荷泵采用0.35μm CMOS工艺...