一种基于BCD工艺的宽压-宽温电流基准电路

设计了一种基于BCD工艺的宽压-宽温电流基准电路.利用片上多晶硅电阻的温度系数受工艺影响较小的特点,选定其为基准电流定义单元.分析片上电阻温度特性,并设计与其温度系数相等的参考电压,加载到电阻上,从而实现了温度系数很低的基准电流.分析了高温下三极管寄生元件漏电现象,通过添加补偿管,提高了基准电流在高温下的稳定性.电流基...     

吸收电路在模拟电路设计中的技术研究

针对模拟电路实际设计中,电子器件容易损坏的问题,研究了几种不同的吸收电路,通过在器件两端并联电容、电阻以及二极管等措施来改善其电压和电流尖峰脉冲,最后通过PSPICE仿真软件验证了理论分析的正确性。     

LED灯具智能检测装置

本设计采用单片机STC89C52为主控芯片,通过AD0804对LED电路进行电流检测反馈给单片机,单片机对电流值进行判断,若电流在一定范围内,通过改变数控电阻X9313的电阻,使得LED电路保持恒流状态,若电流大于一定范围,启动蜂鸣器报警,提示用户更换LED灯具,从而达到LED电路中若有LED短路导致电路电流增大使得电路耗能的情况下,进行节能控制。     

新型高精度CMOS电流比较器

分析了当前几种高性能CMOS电流比较器的优缺点,并设计了一种新颖的电流比较器电路。该电路由3部分组成,具有负反馈电阻的CMOS反相放大器、1组乙类推挽放大器和1组甲乙类推挽放大器。由于CMOS反相放大器的负反馈电阻有效地减小了输入级电路的输入、输出阻抗,从而使得电流比较器的瞬态响应时间变短,反应速度加快。在CSMC 0.35μm模拟CMOS工艺模型下,使用HSPICE仿真器对电路进行仿真,结果表明设计的CMOS电流比较器与目前报导的最快的电流比较器延时几近相等,而且可识别的电流精度高于常见的几种高精度电流比较器。     

DC/DC转换器中电流采样电路的设计

设计了一种用于DC/DC开关电源转换器的新型电流采样电路.常见的电流采样电路是通过检测采样管串联电阻上压降来得到采样电流,而该采样电路是通过检测开关管串联电感上压降来得到采样电流的.由于后者所需电阻更少,从而降低了采样电路的功耗,提高了效率;并且由于电感上压降对采样电流变化的灵敏度更高,有效地提高了采样的精度.     

一种高精度数字可调片上振荡器设计

在传统的电路基础上对电流、电压基准电路进行补偿,设计一种高精度数字可调CMOS片上振荡器电路.利用电阻和PNP管相反的温度系数产生的自偏置基准电流电路PTAT,NTAT两路电流,叠加得到一路与温度无关的基准电流上,实现了温度补偿;利用电阻网络补偿工艺产生高PSRR带隙基准电路电压的频率误差;数字修调寄存器粗调电流用以选择频率,微调电阻用以调节精度.经流片测试表明,该振荡器频率2 MHz,4 MHz可选,2 MHz可调精度达±0.1%;4 MHz可调精度达±0.125%.     

高精度低功耗电流采样电路设计

为了实现低功耗高精度电流检测,文中设计了一种基于运算放大器的具有对称结构的电阻采样结构,该结构不仅实现采样电压和采样电流的高线性度,而且能实现对微弱采样信号的可靠检测。设计的电路架构中包含5个电流-电压转换阶段,基于Hspice仿真,设计电路内部匹配电阻网络,以减小输入失调电压对采样的影响,拓展共模输入范围。该采样电路架构通过某0.35μm BCD工艺实现,版图面积仅为0.12 mm2,实测结果证明其工作电流小于1μA,采样电压检测精度高达5 mV,且具有高速响应能力。     

车用仪表背光灯的LED线性恒流驱动电路设计

阐述了可用于车用仪表背光灯的高精度LED线性恒流驱动芯片设计,重点讨论在设计并联方式LED线性恒流驱动电路时如何消除连线分布电阻的影响,并推出一种新颖的可消除连线分布电阻影响的电路,最终通过电路模拟测试加以验证.研究结果表明,在设计高精度、高稳定性、大电流、并联方式LED线性恒流驱动电路时,消除连线分布电阻影响很有必要...     

微弱电流测量电路的设计和仿真

介绍了微弱电流测量原理,使用运放电流反馈法设计了一种微小电流测量电路。选择具有极低输入偏置电流和失调电压的运放AD8603,合理选择反馈电阻的大小,设计多级放大与电压跟随级电路。PSPICE仿真结果表明,本电路的测鼍精度为1nA．     

权电流型D/A转换器的设计

权电流网络用于克服电阻网络D／A转换器中模拟开关的导通电阻和导通压降。利用倒Ⅱ型电阻网络设计了一种新颖的权电流型D／A转换器。相比由倒T型电阻网络组成的权电流型D／A转换器，该电路具有明显的优点，使其在电子技术应用领域有重要的现实意义和实用价值。     

智能化数字工频多用表的设计与研究

主要介绍一种以AT90S8535单片机为核心的智能化数字工频多用表。用以分档测量并显示单相交流电压、电流,以及功率因数,重点讨论了它的外围硬件电路和软件设计,提高了测量精度和速度,具有十分广阔的应用前景。     

Fast handover solution for network-based distributed mobility management in intelligent transportation systems

The current IP mobility protocols are called centralized mobility management (CMM) solutions, in which all data traffic and management signaling messages must be forwarded to an anchor entity. In some vehicle scenarios, vehicles may move as a group from one roadside unit to another (i.e., after traffic lights or traffic jams). This causes data traffic and exchanged mobility messages to peak at the anchor entity and, consequently, affects the network performance. A new design paradigm aimed at addressing the anchor entity issue is called distributed mobility management (DMM); it is an IETF proposal that is still being actively discussed by the IETF DMM working group. Nevertheless, network-based DMM is designed based on the well-known network-based CMM protocol Proxy Mobile IPv6 (PMIPv6). There is no significant difference between network-based DMM and PMIPv6 in terms of handover latency and packet loss. Because vehicles change their roadside unit frequently in this context, the IP addresses of mobile users (MUs) require fast IP handover management to configure a new IP address without disrupting ongoing sessions. Thus, this paper proposes the Fast handover for network-based DMM (FDMM) based on the Fast Handover for PMIPv6 (PFMIPv6). Several modifications to PFMIPv6 are required to adapt this protocol to DMM. This paper specifies the necessary extensions to support the scenario in which an MU has old IP flows and hence has multiple anchor entities. In addition, the analytic expressions required to evaluate and compare the handover performance of the proposed FDMM and the IETF network-based DMM have been derived. The numerical results show that FDMM outperforms the IETF network-based DMM in terms of handover latency, session recovery and packet loss at the cost of some extra signaling.     

锑化铟锭条的全自动霍耳效应测试系统

为了解决InSb锭条霍耳效应的测试任务‘研制出一套微机控制的全自动测试系统,可对各种截面形状的半导体锭条进行无破坏性的霍耳效应测量。本系统包括一台HP-85型计算机和705型扫描器、220型恒流源以及195型数字多用表,一个自制的多功能测试单元。本文叙述了系统的测量原理,分析了系统中各部分仪器和机构的连接配合控制及其具有的功能,介绍了抗干扰问题的解决方法并进行了误差分析。进行了大量的室温下的测量,并与本征理论值比较,证明系统的测量精度与误差分析是相一致的。此系统大大提高了InSb锭条的测量速度和精度,是研究InSb材料(包括其他半导体材料)十分有用的工具。     

Genetic algorithms and method of moments (GA/MOM) for the design ofintegrated antennas

This paper introduces a novel technique for efficiently combining genetic algorithms (GAs) with method of moments (MoM) for integrated antenna design and explores a two example applications of the GA/MoM approach. Integral to efficient GA/MoM integration is the use of direct Z-matrix manipulation (DMM). In DMM a “mother” structure is selected and its corresponding impedance or Z-matrix is filled only once prior to beginning the GA optimization process. The GA optimizer then optimizes the design by creating substructures of the mother structure as represented by the corresponding subsets of the original mother Z-matrix. Application of DMM with GA/MoM significantly reduces the total optimization time by eliminating multiple Z-matrix fill operations. DMM also facilitates the use of matrix partitioning and presolving to further reduce the optimization time in many practical cases. The design of a broad-band patch antenna with greater than 20% bandwidth and a dual-band patch antenna are presented as examples of the utility of GA/MoM with DMM. Measured results for the dual-band antenna are compared to numerical results. Excellent agreement between numerical and measured results is observed     

利用DMM比例测量法检定电阻箱程序设计

本文就传统检定电阻箱方法中存在测量误差较大、操作繁琐、效率低的问题,在介绍了DMM比例测量功能概念,比例法检定电阻箱原理、接线方法和优点的同时,提出了利用DMM比例测量功能实现检定电阻箱的方法,并描述了在LabVIEW 2011开发环境下设计检定电阻箱程序。该方法充分利用了DMM已有的测量和程控功能,除具有操作更简便,效率高和测量误差较小外,更具有易于推广应用和普及前景,对从事计量检定、自动化测量工作者具有很高的参考借鉴价值。     

Predictive Distribution of the Dirichlet Mixture Model by Local Variational Inference

In Bayesian analysis of a statistical model, the predictive distribution is obtained by marginalizing over the parameters with their posterior distributions. Compared to the frequently used point estimate plug-in method, the predictive distribution leads to a more reliable result in calculating the predictive likelihood of the new upcoming data, especially when the amount of training data is small. The Bayesian estimation of a Dirichlet mixture model (DMM) is, in general, not analytically tractable. In our previous work, we have proposed a global variational inference-based method for approximately calculating the posterior distributions of the parameters in the DMM analytically. In this paper, we extend our previous study for the DMM and propose an algorithm to calculate the predictive distribution of the DMM with the local variational inference (LVI) method. The true predictive distribution of the DMM is analytically intractable. By considering the concave property of the multivariate inverse beta function, we introduce an upper-bound to the true predictive distribution. As the global minimum of this upper-bound exists, the problem is reduced to seek an approximation to the true predictive distribution. The approximated predictive distribution obtained by minimizing the upper-bound is analytically tractable, facilitating the computation of the predictive likelihood. With synthesized data and real data evaluations, the good performance of the proposed LVI based method is demonstrated by comparing with some conventionally used methods.     

SDN‐DMM for intelligent mobility management in heterogeneous mobile IP networks

Mobility management applied to the traditional architecture of the Internet has become a great challenge because of the exponential growth in the number of devices that can connect to the network. This article proposes a Software‐Defined Networking (SDN)‐based architecture, called SDN‐DMM (SDN‐Distributed Mobility Management), that deals with the distributed mode of mobility management in heterogeneous access networks in a simplified and efficient way, ensuring mainly the continuity of IP sessions. Intent‐based mobility management with an IP mapping schema for mobile node identification offers optimized routing without tunneling techniques, hence, an efficient use of the network infrastructure. The simplified mobility control API reduces both signaling and handover latency costs and provides a better scalability and performance in comparison with traditional and SDN‐based DMM approaches. An analytical evaluation of such costs demonstrated the better performance of SDN‐DMM, and a proof of concept of the proposal was implemented in a real environment.     

基于安全节能的电源控制器开发

针对目前电源充电器的安全和能源浪费的问题,提出一种可以应用于移动设备的安全并且节能的电源控制器的设计方法,重点设计了电流继电器的电路。通过设计改进电流继电器的电流取样电路、电压放大电路、精密整流电路、比较和触发电路、继电气控制电路等部分电路,使电源在充电完成后断开,从而达到节能安全的目的。实验结果证明,电源控制器在电源充电结束后,电流减小到75 mA后断开充电电源,比现有充电器的安全性和节能性都有较大提高。     

双极型高精度大负载电流集成电压基准源设计

设计并实现了一种基于双极型工艺的2.5V高精度大负载电流集成基准电压源电路,通过对传统带隙基准电路的改进,设计中增加了电源电压分配电路、电流反馈电路和大电流驱动电路,实现高精度大负载电流的目标.通过Cadence软件平台下的Spectre仿真器对电路的温度系数、负载调整率、噪声、交流电源纹波抑制比、负载电流、启动时间等电参数进行仿真验证,得到了初始精度±0.5%,在-40～85℃范围内温度系数小于6×10-6/℃,负载电流0～50 mA,电源电压4.5～36 V,输出为2.5 V的集成电压基准源电路.该电路采用6 μm/36 VK极型工艺生产制造,芯片面积为1.7 mm×2.1 mm,具有过热保护、过流保护和反接保护功能.     

一种用于电流舵DAC的SDR校正技术

提出了一种基于电流舵DAC的SDR校正技术。首先采用拆分电流源的方法,增加了待校正电流源的个数。然后采用动态组合的方式,减小了电流源的失配误差,提高了DAC的静态与动态性能。与DMM校正技术相比,该SDR校正技术具有更小的残余误差、更好的静态与动态性能。采用40 nm CMOS工艺实现了一种14位200 MS/s的电流舵DAC,并进行了仿真。结果表明,通过数字校正,该DAC的INL与DNL分别从1.5 LSB和0.5 LSB降低到0.33 LSB和0.25 LSB,SFDR在整个Nyquist带宽内均大于70 dB。