多通道神经信号再生集成电路

介绍了一个六通道的神经信号再生集成电路.每一个通道均由检测电路和激励电路组成.检测电路用低噪声、高共模抑制比的仪器放大器从神经元的上端探测神经信号.激励电路中,采用反相运算放大器来进一步放大神经信号,放大的神经信号通过一个缓冲器来激励受损神经的下端神经元,实现了神经信号的传递,从而实现再生的功能.电路采用CSMC0.5 μm CMOS工艺设计,整个六通道的芯片版图面积为1.9 mm×1.6 mm.电路的后仿结果如下:在士2.5 V的供电电压下,单通道电路的功耗为3.9 mW;在100 Hz到7 kHz的频率范围内,等效输入噪声为25.4 nV/sqrt(Hz);增益带宽积达到7.6MHz,可实现60 dB到110 dB的可调增益,输出阻抗为6.2 Ω.     

一种带共模反馈电路的套筒式全差分运算放大器

基于Chartered 0.35 μm工艺,设计了一种带共模反馈电路的套筒式全差分运算放大器.该电路主要由套筒式结构的主运放、偏置电路和共模反馈电路组成.仿真结果表明,设计的电路开环增益为79.4 dB,单位增益带宽为179 MHz,相位裕度为75.5°(负载Cload= 3 PF),功耗为2.31 mW.提出了一种全...     

一种高增益带宽积CMOS跨导运算放大器

提出了一种高增益带宽积CMOS跨导运算放大器,它采用多级前馈补偿结构。该跨导运算放大器采用调零电阻补偿技术,取消了一个非主极点,以提高电路的增益带宽积。电路采用0.18 μm 标准CMOS工艺进行设计,并采用Hspice工具仿真。仿真结果表明,在1.2 V工作电压下,直流增益为71 dB,增益带宽积为1.4 GHz,功耗为2.2 mW。     

CMOS图像传感器中可编程增益放大器的设计

设计了一个低功耗宽摆幅全差分开关电容可编程增益放大器(PGA).该放大器可实现近似1 dB步进,0～15 dB增益变化范围,可用于CMOS图像传感器.提出了一种可调补偿电容的运算跨导放大器(OTA),通过补偿电容调节OTA带宽,大大降低了PGA的功耗.采用TSMC 3.3 V 0.18 μm工艺,在20 MSPS采样率下,使用Hspice仿真.结果显示,电路功耗仅为7 mW,输出摆幅为轨至轨,精度为12位.     

一款适用于高速读出电路的输出级运算放大器设计

〖JP+1〗CMOS运算放大器是红外探测器系统读出电路的重要模块,其性能直接影响红外读出电路性能。本文设计了一款适用于高速读出电路的输出级运算放大器,在负载电阻100 kΩ,负载电容25 pF的条件下,使读出电路的工作频率大于20 MHz。输出级运算放大器由折叠共源共栅差分运放和甲乙类推挽反相运放级联构成。折叠共源共栅差分运放可以实现电路高增益、大输出电压范围和高输出阻抗,同时可以有效减小放大器输入端的米勒电容效应。甲乙类推挽反相运放具有高电压电流转换效率,可以灵活地从负载得到电流或者向负载提供电流,实现高电流增益,驱动大负载。两级运放之间通过米勒电容实现频率补偿,保证运放的稳定性。本文设计的高速输出级运算放大器基于SMIC 018μm工艺设计,最终实现指标:功耗不大于10mW,运放增益>84dB,相位裕度79°,单位增益带宽>100 MHz,噪声78 μV(1～500 MHz),输出电压范围1～5 V,建立时间<15ns。通过设计高速输出级运算放大器,红外读出电路的读出速率和帧频得到有效提高。     

一种高CMRR高增益运算放大器的设计

设计了一种基于TSMC 0.5 μm工艺的高共模抑制比、高增益运算放大器。针对该运放的结构,提出了相应的频率补偿方法,使得电路具有较好的稳定性。该运放可用于生物电势信号检测等对共模抑制比要求较高的场合。仿真结果表明,电路的共模抑制比高达137 dB,低频增益为117 dB,单位增益带宽为6.36 MHz,功耗仅为227 μW。     

一种全差动增益增强型跨导运算放大器

设计了一种低电压全差动增益增强CMOS运算跨导放大器。主运放为一个P管输入的折叠式共源共栅结构,两个辅助运放被设计用来提升电路的输出阻抗和开环增益。主运放采用了一种改进的开关电容共模反馈电路,有更快的建立时间和更高的精度。电路采用中芯国际(SMIC)0.18μm混合信号CMOS工艺设计,1.8 V电压供电,仿真结果表明,运算放大器的开环直流增益为92.2 dB,单位增益带宽可达504 MHz。     

一种高增益全差分运算放大器的分析与设计

采用增益提高技术,设计了一种高增益全差分运算放大器,其主运放和两个辅助运放均为全差分折叠式共源共栅结构,并带有连续时间共模反馈电路。详细地分析了由增益增强结构为此运放带来的零极点对。该运算放大器采用TSMC 0.18 μm CMOS工艺设计,开环直流增益可达138 dB,单位增益带宽为252 MHz。     

高性能Rail-to-Rail恒定跨导CMOS运算放大器

基于UMC的0.6μm BCD 2P2M工艺,探讨了一种高性能Rail-to-Rail恒定跨导CMOS运算放大器.该运算放大器的输入级采用互补差分对,其尾电流由共模输入信号来控制,以此来保证输入级的总跨导在整个共模范围内保持恒定.输出级采用ClassAB类控制电路,并且将其嵌入到求和电路中,以此减少控制电路电流源引起的噪声和失调.为了优化运算放大器低频增益、频率补偿、功耗及谐波失真,求和电路采用了浮动电流源来偏置.该运算放大器采用米勒补偿实现了18MHz的带宽,低频增益约为110dB,Rail-to-Rail引起的跨导变化约为15%,功耗约为10mW.     

一种全差分增益增强型运算放大器的设计

设计了一种用于高速ADC中的全差分运算放大器。该运算放大器由主运放、4个辅助运放和一种改进型开关电容共模反馈电路组成,主运放采用折叠式共源共栅结构,并引入增益增强技术提高增益。采用SMIC 0.18μm,1.8 V工艺,在Cadence电路设计平台中利用Spectre仿真,结果表明：运放增益达到115 dB,单位增益带宽805 MHz,而功耗仅为10.5 mW,运放在8 ns的时间内可以达到0.01%的建立精度,可用于高速高精度流水线( Pipelined) ADC中。     

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.