一种开关电容带隙基准电压源

设计了一款高精度、低线性调整率的开关电容带隙基准电压源。分析了NMOS开关高温漏电流对基准输出电压精度的影响,提出了一种高温漏电补偿电路。偏置电路采用多个共源共栅结构的电流镜,增大了从电源到输出的阻抗,降低了基准电压的线性调整率。利用虚拟管抵消了开关关断时带来的沟道电荷注入效应和时钟馈通效应,提高了基准输出电压的精度。该电路基于0.35μm CMOS工艺设计,仿真结果表明,基准源能稳定输出1.1 V电压,建立时间为5.9μs;在-55～125℃,温度系数为1.38×10^-5/℃;27℃下,在2.7～5 V电源电压范围内,线性调整率为0.9 mV/V;电路总静态电流为35.1μA。     

一种高精度二阶温度补偿带隙基准电路设计

基于通过负温度系数电压控制工作于亚阈值区MOS管栅压产生随温度变化的补偿电流原理,采用中芯国际0.18μm CMOS工艺,设计了一款高精度二阶温度补偿带隙基准电压源。测试结果表明,当电源电压大于1.6V时,电路能够产生稳定的1.21V输出电压;在电源电压为1.6~3.4V,-20~135℃温度范围内,最小温度系数为2×10-6/℃,最大温度系数为3.2×10-6/℃;当电源电压在1.6~3.4V之间变化时,输出电压偏差为0.6mV,电源调整率为0.34mV/V;在1.8V电源电压下,电源抑制比为69dB,因此能够适应于高精度基准源。     

一种高温度性能的CMOS带隙基准源

提出了一种正负温度系数电流产生电路,使用分段线性温度补偿技术用于传统的电流模式基准电路中,改善CMOS带隙基准电路在宽温度范围内的温度漂移.采用0.18μm CMOS混合信号工艺,对该电路进行了设计.在1.8V的电源电压条件下,基准输出电压为0.801 V,温度系数在-40℃-125℃范围内可达到2.7ppm/℃,电源电压从1.5V变化到3.3V的情况下,带隙基准的输入电压调整率为1.2mV/V.     

基于△VGS高阶温度补偿的高精度CMOS带隙基准源

利用两个工作在亚阈区的MOS管的栅源电压差△VGS产生高阶补偿量,对传统的BJT带隙基准源进行高阶温度补偿。设计一种基于△VGS高阶温度补偿的高精度CMOS带隙基准源。电路基于CSMC 0.5um标准CMOS工艺设计,仿真结果表明：在5V电源电压下,基准输出电压为1.258V;在-40～125℃的温度范围内,温度系数为1.24ppm/℃;低频时电源抑制比PSRR为-68dB;电源电压在3.5～6.5V范围内工作,线性调整率为0.4mV/V。适用于高精度带隙基准源。     

一种具有大电流驱动能力的低温漂带隙基准电压源

基于XFAB 0.6 μm CMOS工艺,设计了一种具有大电流驱动能力的低温度系数带隙基准电压源。通过设置不同温度系数的电阻的比值,实现带隙基准的2阶曲率补偿。采用新的电路结构,使基准源具有驱动10 mA以上负载电流的能力。经过Hspice仿真验证,常温基准输出电压为2.496 V,-55 ℃~125 ℃温度范围内的温度系数是3.1×10-6/℃;低频时,电源电压抑制比为-77.6 dB;供电电压在4~6 V范围内,基准输出电压的线性调整率为0.005%/V;负载电流在0~10 mA范围内,基准输出电压波动为219 μV,电流源负载调整率为0.022 mV/mA。     

基于低压高精度运放的带隙基准电压源设计

基于传统带隙基准源的电路结构,采用电平移位的折叠共源共栅输入级和甲乙类互补推挽共源输出级改进了其运算放大器的性能,并结合一阶温度补偿、电流负反馈技术设计了一款低温度系数、高电源电压抑制比(PSRR)的低压基准电压源。利用华润上华公司的CSMC 0.35μm标准CMOS工艺对电路进行了Hspice仿真,该带隙基准源电路的电源工作范围为1.5～2.3 V,输出基准电压为(600±0.2)mV;工作温度为10～130℃,输出电压仅变化8μV,温度系数为1.86×10-6/℃,低频时PSRR为-72 dB。实际流片进行测试,结果表明达到了预期结果。     

一种改进型低温度系数带隙基准源电路

在传统带隙基准源的基础上,设计了一种改进型带隙基准源电路,能很好地抑制三极管集电极电流变化对输出的影响,获得很低的温度系数和很高的电源电压抑制比。基于BCD 0.18 μm工艺库,仿真结果表明,当电源电压VIN为4.5 V,温度范围为-40 ℃~140 ℃时,基准源电路的输出电压范围为1.2567~1.2581 V,温度系数为6.3 ×10-6/℃;电源电压在2.5~5 V范围内变化时,基准源电路输出的最大变化仅为1.66×10-4 V,线性调整率为0.006 64 %;低频电源电压抑制比高达97 dB。过温保护电路(OTP)仿真表明,该基准源电路有良好的温度特性,温度不高于140 ℃都可正常工作。     

一种新型高精度曲率补偿的带隙基准源

采用2个双端差分输入放大器(DDIA),设计了一种新型高精度曲率补偿的带隙基准源。其中一个DDIA产生PTAT电流,得到1阶补偿的基准电压,另一个DDIA产生与温度非线性相关的补偿电压,对基准电压的温度曲线进行曲率补偿,得到高阶温度补偿的参考电压。该电路基于SMIC 0.18 μm标准CMOS工艺,仿真结果表明:在3.3 V电源电压下,基准输出电压为1.171 9 V;在-40 ℃～125 ℃的温度范围内,温度系数为1.48×10-6/℃;低频率时,电源抑制比(PSRR)为-66 dB。电源电压在2.5～4 V范围内,线性调整率为0.6 mV/V。     

低功耗低温漂高PSR带隙基准电压源的设计

在专用医学微弱信号放大电路中,需要非常精准的电压源,为此,提出了一种新型的带隙基准电压源,采用低温补偿和高温补偿相结合的温度补偿方式,输出带隙基准电压为1.109 V,在-40~125℃范围内的温度系数为0.445~0.604 ppm/℃。同时采用了预稳压器来提高电路的PSR(电源抑制),使得PSR在10 Hz时为-127.5 dB,在100 kHz时达到-63 dB。文中设计的电路静态电流只有10μA,消耗的功耗在36μW左右。该带隙基准电路还有不随工艺变化的特点,工艺差别使输出电压最大产生61.5μV的变化。     

一种低温漂的CMOS带隙基准电压源的研究

为了满足深亚微米级集成电路对低温漂、低功耗电源电压的需求,提出了一种在0.25μm N阱CMOS工艺下,采用一阶温度补偿技术设计的CMOS带隙基准电压源电路。电路核心部分由双极晶体管构成,实现了VBE和VT的线性叠加,获得近似零温度系数的输出电压。T-SPICE软件仿真表明,在3.3 V电源电压下,当温度在-20~70℃之间变化时,该电路输出电压的温度系数为10×10-6/℃,输出电压的标准偏差为1 mV,室温时电路的功耗为5.283 1 mW,属于低温漂、低功耗的基准电压源。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.