一种CMOS绿色模式AC／DC控制器振荡器电路

此振荡器专门针对恒压恒流（CV—CC）控制、频率抖动（Frequency Shuffling）技术。采用电流模脉宽调制控制方案的电池充电芯片设计,锯齿波信号的线性度较好,当负载电路减小时,自动进入Burst Mode状态提高系统的效率。整个电路基于1．0tun40V CMOS工艺设计,通过Hspice完成了整体电路前仿真验证和后仿真,仿真结果表明,振荡电路的性能较好,可广泛应用在PWM等各种电子电路中。     

用于单片集成AC/DC变换器的带隙基准源设计

在对传统带隙基准源基本原理分析的基础上,提出了一种适用于单片集成AC/DC变换器的带隙基准电路。该电路采用无运放的带隙结构, 避免了运放失调电压对基准源的影响。基于LITEON 1μm HV BiCMOS工艺,Hspice仿真结果表明,该基准源产生1.238V的基准电压,电源抑制比高达60dB,在-40℃-140℃温度范围内,基准电压仅变化3.9mV,温度系数为16.6×10^-6/℃, 完全满足AC/DC变换器对其性能的要求。     

A power management system for energy harvesting and wireless sensor networks application based on a novel charge pump circuit

Energy Harvesting circuits are developed as an alternative solution to supply energy to autonomous sensor nodes in Wireless Sensor Networks. In this context, this paper presents a micro-power management system for multi energy sources based on a novel design of charge pump circuit to allow the total autonomy of self-powered sensors. This work proposes a low-voltage and high performance charge pump (CP) suitable for implementation in standard complementary metal oxide semiconductor (CMOS) technologies. The CP design was implemented using Cadence Virtuoso with AMS 0.35μm CMOS technology parameters. Its active area is 0.112 mm². Consistent results were obtained between the measured findings of the chip testing and the simulation results. The circuit can operate with an 800 mV supply and generate a boosted output voltage of 2.835 V with 1 MHz as frequency.     

面向频谱感知的传感器网络设计

针对认知无线电网络、频谱监测等领域对宽频段频谱感知的需求,基于无线传感器网络的特点,提出了一种面向频谱感知的传感器网络设计方案,包括分簇的网络结构、分频段的协作感知机制以及感知结果的协作处理机制,分析了实现这种方案的关键技术,为利用传感器网络进行宽频带协作频谱感知提供了一种可选的方案。     

CMOS图像传感器中电荷非完全转移的影响分析

A method to judge complete charger transfer is proposed for a four-transistor CMOS image sensor with a large pixel size.Based on the emission current theory,a qualitative photoresponse model is established to the preliminary prediction.Further analysis of noise for incomplete charge transfer predicts the noise variation.The test pixels were fabricated in a specialized 0.18μm CMOS image sensor process and two different processes of buried N layer implantation are compared.The trend prediction corresponds with the test results,especially as it can distinguish an unobvious incomplete charge transfer.The method helps us judge whether the charge transfer time satisfies the requirements of the readout circuit for the given process especially for pixels of a large size.     

无线传感器网络的路由协议分析

无线传感器网络是由大量微型传感器节点组成的一个自组织的网络系统,路由协议是其关键技术之一.现有的路由协议分为:能量感知路由协议、以数据为中心的路由协议、基于地理位置的路由协议、可靠的路由协议和层次路由协议五类,对每类协议的特点和比较典型的协议进行了介绍.     

PMOS-switching dual-path charge pump in standard twin-well CMOS technology

In this article a new charge pump circuit is presented, which is feasible for implementation with the standard twin-well CMOS process. The proposed charge pump employs PMOS-switching dual charge-transfer paths and a simple two-phase clock. Since charge transfer switches are fully turned ON during each half of the clock cycle, they transfer charges completely from the present stage to the next stage without suffering threshold voltage drop. During one clock cycle, the pump transfers charges twice through two pumping paths which are operating alternately. Test chips have been fabricated in a 0.35-μm twin-well CMOS process. The output voltage of a 4-stage charge pump with each pumping capacitor of 7.36 pF measures 6.7 V under a 1.5 V power supply and 20 MHz clock frequency. It can supply a maximum load current of about 180 μA. Although the proposed circuit exhibits somewhat inferior performances against triple-well charge pumps using additional mask and process steps, it shows at least 60% higher voltage gain at V _DD = 0.9 V, approximately 10% higher peak power efficiency at V _DD = 1.5 V, much larger output current drivability and faster initial output rising than traditional twin-well charge pumps. This new pumping efficient circuit is suitable for design applications with a low-cost standard twin-well CMOS process.     

基于身份的无线传感器网络定位认证方案

在介绍了无线传感器网络定位系统并剖析其各组成部分所面临的安全威胁的基础上,提出了一种基于身份的安全定位认证方案.该认证方案能够有效运用在定位系统的各个部分.安全性分析验证了方案能够有效阻止针对定位系统各种形式的网络攻击.对相关方案的性能分析和比较表明,所提出的方案在网络资源消耗、有效性和可实现方面都比较适合无线传感器网络.     

一种新型的基于无源射频身份识别应答器的电源供给方案

提出了一种基于全集成的无源射频身份识别(RFID)应答器芯片的电源供给方案,并在特许半导体的0.35μm嵌入EEPROM的CMOS工艺线上流片成功.提出的AC/DC和DC/DC电荷泵能够为RFID的应答器芯片提供稳定的工作电压,同时具有极低的功耗和很高的充电效率.还给出了电压倍增器的分析模型、与其他电荷泵的升压原理的比较以及仿真结果和芯片测试结果.     

一种新型的基于无源射频身份识别应答器的电源供给方案

提出了一种基于全集成的无源射频身份识别(RFID)应答器芯片的电源供给方案,并在特许半导体的0.35μm嵌入EEPROM的CMOS工艺线上流片成功.提出的AC/DC和DC/DC电荷泵能够为RFID的应答器芯片提供稳定的工作电压,同时具有极低的功耗和很高的充电效率.还给出了电压倍增器的分析模型、与其他电荷泵的升压原理的比较以及仿真结果和芯片测试结果.     

Incomplete charge transfer in CMOS image sensor caused by Si/SiO2 interface states in the TG channel

CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO₂ interface state traps in the charge transfer path, which reduces the charge transfer efficiency and image quality. Until now, scholars have only considered mechanisms that limit charge transfer from the perspectives of potential barriers and spill back effect under high illumination condition. However, the existing models have thus far ignored the charge transfer limitation due to Si/SiO₂ interface state traps in the transfer gate channel, particularly under low illumination. Therefore, this paper proposes, for the first time, an analytical model for quantifying the incomplete charge transfer caused by Si/SiO₂ interface state traps in the transfer gate channel under low illumination. This model can predict the variation rules of the number of untransferred charges and charge transfer efficiency when the trap energy level follows Gaussian distribution, exponential distribution and measured distribution. The model was verified with technology computer-aided design simulations, and the results showed that the simulation results exhibit the consistency with the proposed model.     

无线传感器网络的轻量级安全体系研究

结合无线传感器网络现有的安全方案存在密钥管理和安全认证效率低等问题的特点,提出了无线传感器网络的轻量级安全体系和安全算法。采用门限秘密共享机制的思想解决了无线传感器网络组网中遭遇恶意节点的问题;采用轻量化ECC算法改造传统ECC算法,优化基于ECC的CPK体制的思想,在无需第三方认证中心CA的参与下,可减少认证过程中的计算开销和通信开销,密钥管理适应无线传感器网络的资源受限和传输能耗相当于计算能耗千倍等特点,安全性依赖于椭圆离散对数的指数级分解计算复杂度;并采用双向认证的方式改造,保证普通节点与簇头节点间的通信安全,抵御中间人攻击。     

Column readout circuit with improved offset mismatch and charge sharing for CMOS image sensor

High linearity and low noise column readout chain are two key factors in CMOS image sensor. However, offset mismatch and charge sharing always exist in the conventional column wise readout implementation, even adopting the technology of correlated double sample. A simple column readout circuit with improved offset mismatch and charge sharing for CMOS image sensor is proposed in this paper. Based on the bottom plate sampling and fixed common level method, this novel design can avoid the offset nonuniformity between the two buffers. Also, the single buffer and switched capacitor technique can effectively suppress the charge sharing caused by the varied operating point. The proposed approach is experimentally verified in a 1024 × 1024 prototype chip designed and fabricated in 55 nm low power CMOS process. The measurement results show that the linear range is extended by 20%, the readout noise of bright and dark fields is reduced by 40% and 30% respectively, and the improved photo response nonuniformity is up to 1.16%. Finally, a raw sample image taken by the prototype sensor shows the excellent practical performance.     

一种新型光纤光栅无线传感网络及路由设计

传统的光纤光栅传感网络具有灵活性低、移动性差等缺点.文章作者构建了一种新型的光纤光栅无线传感网络,该网络融合了无线通信和光纤光栅传感的优点.同时还设计了节点结构,并根据实际应用场景提出了该传感网络的路由协议--RT(路由选择表)协议.在NS2(Network Simulator)中,从分组投递率、时延和能耗等3方面与Flooding协议进行了比较分析,结果显示RT协议更适合该新型传感网络.     

数据采集型传感器网络结构的生成机制研究

对树形网络结构中的3种典型采集树协议,随机采集树生成协议、距离-能量采集树生成协议和负载均匀的采集树生成协议做了详细的介绍,并分析了各个协议的优缺点.结合仿真结果分析了各协议对网络性能的影响.     

A CMOS G_m-C complex filter with on-chip automatic tuning for wireless sensor network application

A G_m-C complex filter with on-chip automatic tuning for wireless sensor networks is designed and implemented using 0.18μm CMOS process.This filter is synthesized from a low-pass 5th-order Chebyshev RLC ladder filter prototype by means of capacitors and fully balanced transconductors.A conventional phase-locked loop is used to realize the on-chip automatic tuning for both center frequency and bandwidth control.The filter is centered at 2 MHz with a bandwidth of 2.4 MHz.The measured results show that the filter provides more than 45 dB image rejection while the ripple in the pass-band is less than 1.2 dB.The complete filter including on-chip tuning circuit consumes 4.9 mA with 1.8 V single supply voltage.     

多路输出单端反激式开关电源设计

在阐述了基于TOPSwitch系列芯片设计的单片反激式开关电源原理的基础上，详细介绍了一种用于智能仪表小功率多输出AC／DC开关电源的设计方法。该电源主电路采用反激式电路，应用反馈手段和脉冲调制技术实现多路电压的稳定输出。最后，给出了实验结果。试验表明，该电源具有良好的性能。     

用于相变存储器的超低输出纹波2X/1.5X电荷泵

本文针对相变存储器编程驱动电路,提出了一种超低输出电压纹波的开关电容型电荷泵。该电荷泵可根据输入电压的不同,自适应工作在2X/1.5X升压模式之间,以获得更高的电源转换效率。相比于传统开关电容型电荷泵,在充电阶段泵电容被充电至预先设定的电压值Vo-VDD(Vo为预期的输出电压);放电阶段,泵电容串联在输入电压VDD与输出端,通过此方法将电荷泵输出端电压稳定在Vo,并有效的降低了由于电荷分享所造成的输出纹波。在中芯国际40nm标准CMOS工艺模型下,对电路进行了仿真验证,结果表明在输入电压为1.6-2.1V,输出2.5V电压,最大负载电流为10mA,输出电压纹波低于4mV,电源效率最高可达91%。     

Design of a low-power CMOS transceiver for semi-passive wireless sensor network application

A 50 kbps/ISM band (902 − 926 MHz) low power transceiver for short-range wireless sensor networks (WSN) has been designed in 0.18 μm 1-poly-6 metal CMOS technology and occupy 950 μm × 800 μm. The proposed WSN transceiver designed based on an improved version of the Amplitude-Shift Keying communication scheme has a better continuous RF modulated carrier waveform as well as does not require complex modulator/demodulator circuits. In addition, to reduce power dissipation and increase power efficiency many circuit techniques have been adopted. The power dissipation and the power efficiency of the proposed WSN transceivers are 1.58 mW and 21%, respectively.