一种采用低阈值技术实现的高速模数转换器

在0.35 μm标准CMOS工艺下实现了一款采用低阈值技术的高速流水线模数转换器。该转换器包括采样保持电路、流水线ADC核、时钟电路和基准电路。相比于传统电路,该模数转换器中采样保持电路的放大器采用了低阈值设计技术。其优势在于,在特定工艺下,通过低阈值器件补偿放大器可实现高增益带宽,提高了模数转换器的速度。同时,设计了一种全新的保护电路,可有效保证电路的正常工作。采用一种独特的偏置电路设计技术,不仅能够优化跨导放大器的增益和带宽,还可以调节MOS器件工作状态。转换器采用4 bit+8×1.5 bit+3 bit的十级流水线架构,实现了14位精度的模数转换功能。在5 V电源100 MHz时钟下,仿真结果表明,SINAD为74.76 dB,SFDR为87.63 dBc,面积为5 mm×5 mm。     

采用前端RC匹配技术的12位40兆赫兹无采样保持的流水线模数转换器

12位40兆赫兹流水线模数转换器采用了前端RC时间常数匹配技术和一组相应的不同占空比时钟时序方法。在不需要繁琐的后端版图仿真验证的情况下,可以很好的提高无采样保持结构流水线模数转换器的线性度。本设计采用0.13微米中芯国际工艺流片实现。通过取消采样保持器技术,运放共享技术和低功耗运放设计来确保低功耗和小面积的设计要求。在40兆赫兹采样时钟和10.2兆赫兹正弦输入信号下,此模数转换器可以达到78.2dB 的无杂散动态范围（SFDR）,60.5dB 的信噪失真比（SNDR）和 -75.5dB 的总谐波失真,在1.2伏的电源电压下,功耗仅为15.6毫瓦。     

基于0.18μm CMOS工艺的 0.23pJ/step 11.05bit 有效位 125MS/s 流水线型模数转换器

本文描述了一款基于0.18μm标准CMOS工艺设计的12位 125-MS/s 的流水线型模数转换器。为了提高采样的线性度,采用了栅压自举开关和底极板采样技术。其微分非线性和积分非线性分别为0.79 LSB和0.86 LSB。在输入频率为10.5MHz时,本模数转换器可以实现11.05bit的有效位,在输入频率接近奈奎斯特频率时,仍可以达到10.5 bit的有效位。本模数转换器工作电压为1.9V,功耗62 mW,面积1.17 mm2,其中包含片内参考电压产生电路。本模数转换器的FOM值为0.23 pJ/step。     

12bit10MS/s流水线结构模数转换器

介绍了12 bit,10 MS/s流水线结构的模数转换器IP核设计。为了实现低功耗,在采样电容和运放逐级缩减的基础上,电路设计中还采用了没有传统前端采样保持放大器的第一级流水线结构,并且采用了运放共享技术。瞬态噪声的仿真结果表明,在10 MHz采样率和295 kHz输入信号频率下,由该方法设计的ADC可以达到92.56 dB的无杂散动态范围,72.97 dB的信号噪声失调比,相当于11.83个有效位数,并且在5 V供电电压下的功耗仅为44.5 mW。     

一种时间交叉采样ADC失调与增益误差校准方案

针对时间交叉采样模数转换器的失调、增益误差提出了校准方案.该方案主要通过各通道模数转换器向同一通道校准的方法,首先计算出误差参数,再根据误差参数对数字量进行校准.采用该校准方案对四通道10位640 Msps模数转换器进行校准,经MATlAB仿真,结果表明输入频率为79.14 MHz时,校准后的无杂散动态范围为75.17 dB,信噪比为55.98 dB,有效精度为9.01 bit,比较准前分别提高了24.6 dB、6.47 dB、1.08 bit.     

SFDR高于100dB的14位欠采样循环模数转换器

本文为射频标签(RFID)收发机系统设计了一个高线性,14位357 k采样率的欠采样循环模数转换器。为提高模数转换器的精度,设计中采用了有源电容误差平均(PCEA)技术。并且提出了一种改进的PCEA采样网络,可以消除两个流水级之间的串扰影响。为降低模数转换器的功耗和减小面积,设计采用了运放共享技术,并且去除了采样保持放大级。为补偿不完善的版图设计引入的误差,增加了一个附加的数字校准模块。该模数转换器由180 nm CMOS工艺流水完成,面积为0.65 mm  1.6 mm。在确保SFDR不低于90 dB的条件下,该欠采样模数转换器的输入信号频率高达15.5 MHz;在2.431 MHz输入下,峰值SFDR高达106.4 dB.     

一个低功耗的带片上参考电压缓冲器的12位30兆采样率的CMOS流水线模数转换器

介绍了一个在0.13µm 1P8M CMOS工艺下实现的12位30兆采样率流水线模数转换器。提出了一种消除前端采样保持电路的低功耗设计方法。除了第一级之外,带双输入的两级cascode补偿的运算放大器在相邻级间共享以进一步地减小功耗。该模数转换器在5MHz的模拟输入和30.7MHz的采样速率下达到了65.3dB的SNR,75.8dB的SFDR和64.6dB的SNDR。该芯片在1.2V电源电压下消耗33.6mW。FOM达到了0.79pJ/conv step。     

一种10位50MHz流水线模数转换器的设计

采用每级1.5 bit和每级2.5 bit相结合的方法设计了一种10位50 MHz流水线模数转换器。通过采用自举开关和增益自举技术的折叠式共源共栅运算放大器,保证了采样保持电路和级电路的性能。该电路采用华润上华(CSMC)0.5μm 5 V CMOS工艺进行版图设计和流片验证,芯片面积为5.5 mm2。测试结果表明:该模数转换器在采样频率为50 MHz,输入信号频率为30 kHz时,信号加谐波失真比(SNDR)为56.5 dB,无杂散动态范围(SFDR)为73.9 dB。输入频率为20 MHz时,信号加谐波失真比为52.1 dB,无杂散动态范围为65.7 dB。     

14-bit 100 MS/s 121 mW pipelined ADC

本文实现了一款低功耗、小面积的高速高精度流水线型模数转换器,可以作为IP核应用于片上系统中。该模数转换器应用了逐级尺寸递减、运放共享等技术来实现低功耗的设计。采用分离的双输入通道共享的运算放大器输入端,从而实现运放共享带来的级间串扰、记忆效应等非线性影响的消除。同时,该模数转换器中采用了动态预放大比较器的设计来减小比较器的静态功耗以及回踢噪声的影响。本设计在SMIC 0.18μm CMOS工艺下流片,实现面积开销为3.1mm2。在采样频率为100MHz,输入信号为2.4MHz的情况下,实现无杂散动态范围（SFDR）为82.7dB,信号噪声失真比（SNDR）为69.1dB。在输入信道达到100MHz的情况下,实现SFDR和SNDR分别为81.4dB和65.8dB。该模数转换器的供电电压为1.8V,功耗开销为121mW。     

10 bit 40 MS/s流水线模数转换器的研制

设计了一种10 bit 40 MS/s流水线模数转换器.通过采用自举开关和增益提升的套筒式共源共栅运放,保证了采样保持电路和级电路的性能.该模数转换器采用TSMC 0.35 p.m CMOS3.3 V工艺流片验证,芯片核心面积为5.6 jmm2.测试结果表明,该模数转换器在采样率为40 MHz输入频率为280 kHz时,获得54.5 dB的信噪比和60.2 dB的动态范围;在采样率为46 MHz输入频率为12.6 MHz时,获得52.1 dB的信噪比和60.6 dB的动态范围.     

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.     

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.     

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.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.