电流镜型二次曲率补偿的带隙基准源设计

为提高基准源的温度系数、电压调整率和电源抑制比,采用0.6μm标准CMOS工艺,设计一种采用电流镜复制技术的带隙基准源.仿真结果表明,电路具有结构简单、启动性能好、电压输出灵活稳定、温度范围宽等特点,能够满足模拟集成电路的要求.在3种工艺角模型,-50~+195℃温度变化范围内,其温度系数约为1.632×10-5℃-1,电源抑制比为-70 dB;而在4.5~6.5 V的电源范围内,其电压调整率为4.0×10-4.     

高阶曲率补偿电流模式的CMOS带隙基准源

为获得一个稳定而精确的基准电压,提出了一种适用于低电源电压下高阶曲率补偿的电流模式带隙基准源电路,通过在传统带隙基准源结构上增加一个电流支路,实现了高阶曲率补偿。该电路采用Chartered 0.35μm CMOS工艺,经过Spectre仿真验证,输出电压为800mV,在-40～85℃温度范围内温度系数达到3×10^-6℃^-1,电源抑制比在10kHz频率时可达-60dB,在较低电源电压为1．7V时电路可以正常启动,补偿改进后的电路性能较传统结构有很大提高．     

低功耗高电源抑制比CMOS带隙基准源设计

基于Ahujia基准电压发生器设计了低功耗、高电源抑制比CMOS基准电压发生器电路.其设计特点是采用了共源共栅电流镜,运放的输出作为驱动的同时还作为自身的偏置电路;其次是采用了带隙温度补偿技术.使用CSMC标准0.6μm双层多晶硅n-well CMOS工艺混频信号模型,利用Cadence的Spectre工具对其仿真,结果显示,当温度和电源电压变化范围为-50-150℃和4.5-5.5 V时,输出基准电压变化小于1.6 mV(6.2×10-6/℃)和0.13 mV;低频电源抑制比达到75 dB.电路在5 V电源电压下工作电流小于10 μA.该电路适用于对功耗要求低、稳定度要求高的集成温度传感器电路中.     

一种新型的高性能带隙基准电压源

提出了一种新型的高性能带隙基准电压源,该基准电压源采用共源共栅电流镜提供偏置电流,减少沟道长度调制效应带来的误差,并增加1个简单的减法电路,使得偏置电流更好地跟随电源电压变化,从而提高电路的电源抑制比。整体电路使用CSMC 0.6μm CMOS工艺,采用Hspice进行仿真。仿真结果表明,在-50~ 100℃温度范围内温度系数为2.93×10-5℃,电源抑制比达到-84.2 dB,电源电压在3.5~6.5 V之间均可实现2.5±0.0012 V的输出,是一种有效的基准电压实现方法。     

基于ΔVGS权重的CMOS恒压源

针对全CMOS结构制作恒压源方法中存在的功耗过大问题,提出了一种利用CMOS亚阈值特性的恒压源制作方案.该电路基于NMOS和PMOS处于饱和区工作时,两者的栅源电压随温度变化权重不同的原理,将其作相关运算,得到温度系数极低的恒压输出.基于MOS管亚阈值特性产生的电路模块中的偏置电流很小,导致功耗仅50 μW.采用中芯国际0.18 μm数模混合工艺制造了该电压源结构,测试结果显示,在21～110 ℃的温度范围内,电路的温度系数达到了2.5×10-5/℃.当电源电压达到1.4 V以上时,电路就可以正常工作,且其电源电压抑止比为-57 dB.     

一种超低温漂的带隙基准电压源

为提高带隙基准电压源的温度特性,采用Buck电压转移单元产生的正温度系数对VBE的负温度系数进行高阶曲率补偿.同时使用共源共栅结构(Cascode)提高电源抑制比(PSRR).电路采用0.5 μm CMOS工艺实现,在5 V电源电压下,基准输出电压为996.72 mV,温度范围在-25~125 ℃时电路的温漂系数为1.514 ppm/℃;当电源电压在2.5~5.5 V变化时,电压调整率为0.4 mV/V,PSRR达到59.35 dB.     

基于△V_(GS)权重的CMOS恒压源

针对全CM O S结构制作恒压源方法中存在的功耗过大问题,提出了一种利用CM O S亚阈值特性的恒压源制作方案。该电路基于NM O S和PM O S处于饱和区工作时,两者的栅源电压随温度变化权重不同的原理,将其作相关运算,得到温度系数极低的恒压输出。基于M O S管亚阈值特性产生的电路模块中的偏置电流很小,导致功耗仅50μW。采用中芯国际0.18μm数模混合工艺制造了该电压源结构,测试结果显示,在21~110℃的温度范围内,电路的温度系数达到了2.5×1-0 5/℃。当电源电压达到1.4 V以上时,电路就可以正常工作,且其电源电压抑止比为-57 dB。     

一种低电压、低功耗CMOS基准电压源的设计

本文设计了一种低电压、低功耗、高电源抑制比CMOS基准电压源。该电路基于工作在亚阈值区的MOS管,利用PTAT电流源与微功耗运算放大器构成负反馈系统以提高电源电压抑制比。SPICE仿真显示,在1V的电源电压下,输出基准电压为609mV,温度系数为72ppm/℃,静态工作电流仅为1.23μA。在1-5V的电源电压变化范围内,电压灵敏度为130μV/V,低频电源电压抑制比为74dB。该电路为全CMOS电路,不需要用到寄生PNP三极管,具有良好的CMOS工艺兼容性。     

一种BiCMOS带隙基准电压源的设计

设计了低温度系数、高电源抑制比BiCMOS带隙基准电压发生器电路.综合了带隙电压的双极型带隙基准电路和与电源电压无关的电流镜的优点.电流镜用作运放,它的输出作为驱动的同时还作为带隙基准电路的偏置电路.使用0.6μm双层多晶硅n-well BiCMOS工艺模型,利用Spectre工具对其仿真,结果显示当温度和电源电压变化范围分别为-45~85℃和4.5~5.5 V时,输出基准电压变化1 mV和0.6 mV;温度系数为16×10-6/℃;低频电源抑制比达到75 dB.电路在5 V电源电压下工作电流小于25μA.该电路适用于对精度要求高、温度系数低的锂离子电池充电器电路.     

一种指数曲率补偿CMOS带隙基准源的设计

给出一款带曲率补偿的CMOS带隙基准源电路,该电路利用双极性晶体管电流增益β与温度的指数关系对带隙基准曲率进行补偿,以简单的电路结构获得低的温度系数．电路采用CSMC0．5μm 2P3M mixed signalCMOS工艺设计,Cadence Spectre仿真结果显示,在3．6V的电源电压、-40～85℃范围内,基准源的温度系数为5．0×10-6／℃．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that