基于曲率补偿的低温度系数带隙基准源设计

为了减小基准源输出信号随温度变化的波动,设计了一种基于温度曲率补偿的带隙基准电压源电路结构,采用负反馈箝位技术,简化了电路结构,减小了噪声和失调误差;同时应用β倍增器电流源作为温度曲率补偿电路,有效降低了温度系数。仿真结果表明,在-20~105℃范围内,所设计的带隙基准电压源的温度系数仅为0.904 ppm/℃,低频时电源电压抑制比为46 dB。该电路结构可以有效地提高带隙基准电压源的温度性能。     

一种高阶曲率补偿CMOS带隙基准源的设计

提出了一种低压高阶曲率补偿的CMOS带隙基准电路。电路采用电流模BGR结构,采用对VBE的线性补偿方法。利用BISM 3模型,电源电压可在5V,在-55—125℃温度范围内,温度系数为6.034ppm／℃。在低电源电压,低频下PSRR为-73dB。整个带隙基准电压源具有好的综合性能。     

一种集成稳压电路的设计与研究

设计了一种采用CSMC 0.6um CMOS工艺的集成带隙基准电压源电路.仿真结果表明,在电源电压VDD为5V时,在的温度范围内,电路得到一个温度系数为37.3533ppm/℃,电源抑制比(PSRR)为43.98dB的带隙基准电压输出,性能较为理想.     

一种用于D/A转换器的带隙基准电压源设计

本文设计了一种用于D/A转换器的带隙基准电压源,该电路采用中芯国际(SMIC)0.18 μm CMOS工艺设计,利用Cadence Spectre工具对其仿真,后仿结果表明,1.8V电源电压下,在-40℃～125℃温度范围内,带隙基准电压源的温度系数为4.1ppm/℃,电源抑制比(PSRR)低频时为89dB,在10 kHz时仍可以达到62.4dB.基准输出电压约为406.6mV.该带隙基准电压源能够很好的应用到高分辨DAC中.     

一种高性能BiCMOS带隙基准电压源设计

文章在对带隙基准基本原理与电路结构分析基础上,介绍了一种高精度、低功耗、高电源抑制比的BiCMOS带隙基准电压源电路。该电路的实现是基于0．6μm、5V的BiCMOS工艺。仿真结果表明,该基准电路稳定工作电源电压范围为1．9V～6．4V,在低频下的电源抑制比可达到-88dB,温度变化范围从-25℃至150℃时,温度系数为9．73×10^-6,输出电压误差为1．72mV。     

一种低压高精度的CMOS带隙基准电压源

采用0.5μm CMOS工艺设计了一种高精度低压基准电压源.提出了一种结构比较新颖的基准电压源电路,该基准电压源电路具有较低的温度系数、较大的温度范围和较高的电源抑制比.此外,还增加了提高电源抑制比电路、启动电路,以保证电路工作点正常、性能优良,并使电路的静态功耗较小.Spice仿真结果表明低频时电源抑制比可达70dB;在-40～120℃范围内,输出变化仅为0.004V,温度系数可达25×10-6V/℃;静态功耗小,在电源电压Vdd=3.3V时,总功耗约为0.025mW.     

一种新型CMOS数模转换器的设计与仿真

设计了一种基于R-2R倒梯形电阻网络结构的8位CMOS数模转换器。数模转换器输入采用并行数字输入结构,输出采用模拟电流输出方式,基准电压源采用CMOs带隙基准电压电路,该电路综合了电路启动、温度补偿和电流反馈等技术,通过适当调节电阻,使输出电压具有较低的温度系数。采用Hspice作为设计电路模拟仿真分析的软件工具,仿真结果表明,在5V工作电压下,建立时间小于50ns,电路的积分与微分非线性误差均小于5LSB,功耗小于40mW,达到了设计要求。     

LDO线性稳压器中CMOS带隙基准电路的设计

设计了一款应用于LDO线性稳压器的高性能CMOS带隙基准电路,详细分析了它的工作原理,并给出了具体电路、仿真波形以及分析数据。该电路的主要特点是采用双PN结串联和基极电流补偿的结构,并引入衬底电压产生电路,具有很好的温度特性和很高的电源抑制比。当温度从-40~125℃变化时,温度系数约为37ppm/℃;同时,其电源抑制比(PSRR)为76.3dB。此外,该电路还可为LDO中其它电路模块提供PTAT电流。     

NICA-MPD探测器的低温漂基准电压源设计

基于TSMC BCD 180nm工艺设计并流片测试了一款低压低温漂带隙基准芯片,用于高能物理实验。该芯片主要基于NICA-MPD探测器工程项目的需求,实现在极端温度环境中正常输出电压的功能。该芯片的核心模块带隙基准模块采用二阶温度补偿结构,测试结果表明该芯片在1.8V电源电压下,能稳定输出0.9V电压,功耗约为46.5μW,在-40～120℃内温度系数约为29×10^-6/℃,电源抑制比为-76.8dB。     

基于热敏电阻的多通道高精度温度测量系统

以负温度系数热敏电阻为核心器件设计了多通道高精度温度测量系统.用改进的电压测量电路间接测量热敏电阻的阻值,有效地克服了电压源的干扰,测量精度高,测量分辨率可达0.01℃,测温准确度可达±0.1℃;并且该电路结构简单,成本低、功耗小、体积小,具有很高的实用价值,可用于需要精密测温的系统,如热导率测量仪的温度测量中.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.