基于多阈值技术的超低功耗电路设计

随着工艺进入深亚微米阶段,漏电流带来的静态功耗已经成为不可忽视的部分。多阈值CMOS技术是一种降低电路漏电流功耗的有效方法。本文在延迟不敏感异步电路中应用多阈值CMOS技术,该设计能显著的降低功耗,同时解决了同步电路存在的问题,比如sleep信号的产生,存储元件在sleep模式下数据丢失。这对深亚微米低功耗电路的设计具有一定的实际意义。     

Smoother and Bayesian filter based semi-codeless tracking of dual-frequency GPS signals

The orbit of the Shenzhou IV unmanned spacecraft has been observed four times by jointly using single-frequency GPS receiver, SLR and USB since its successful launch on Dec. 30, 2002. The radial accuracy of orbit determination was better than 2 m[1]. We t…     

高速2CPFSK调制器的设计与实现

针对小型飞行器数据链中信号传输速率的要求,介绍了二进制连续相位的FSK调制原理,提出了基于直接数字频率合成技术的2CPFSK调制器的设计与电路实现.给出了提高频谱纯度的椭圆函数型滤波器的设计,实现了对高速数字信号的2CPFSK调制.通过小型飞行器数据链图像信号的传输应用实验验证:该设计实现了程序自动调节频偏,得到了较小的调制指数,解决了小型飞行器数据链高速数据传输的问题.     

航空设备端口信号测试技术研究

从测试端口信号分析设备功能的实际工作中,总结出测试工作的步骤、方法和要点.叙述了从端口测试大电流、高电压、模拟信号和数字信号的方法;研究出从两台设备之间的连线上测出信号流向的技术,给出了用于指示该流向的电路.基于端口信号测试,可分析出设备的性能,完成功能替代研制,实现进口设备的国产化.     

低噪声放大器直流偏置电路的仿真设计实验

嗓声放大器(Low Noise Amplifier,LNA)是微波系统及其测量仪器中的关键部件之一,其噪声的大小直接影响信号接收灵敏度及系统的可靠性.在晶体管放大电路中,偏置电路为晶体管提供合适的静态工作点,偏置电路设计的重要性不可低估.主要介绍了低噪声放大器中直流偏置电路的仿真设计.     

多阈值神经元电路设计及在多值逻辑中的应用

分析了多阈值神经元工作原理,并提出设计多阈值神经元电路的方法．首先,用两个MOS晶体管组成电压型突触电路,然后又提出一种基于BiCMOS工艺的判别转换开关电路,这种电路以压控电流作为阈值信号,并实现电压到电流的转换．在此基础上,结合限幅电压开关理论提出多阈值神经元阈值判别函数电路的开关级设计方法．最后,从开关级设计了实现三值逻辑中文字、与、或三种基本运算的多阈值神经元电路,用这三种基本运算的多阈值神经元电路可实现任意三值函数的多阈值神经网络．文章还对设计出的电路用PSPICE进行模拟,测量相关参数．模拟结果表明,该文设计的电路不仅实现了正确的逻辑功能,而且速度较快。     

C8051F017构建的智能二线制温度变送器

介绍了由C8051F017构建的智能二线制温度变送器,分析了系统实现的理论依据。硬件采用低功耗线性变换器MAX1616和TLC27L2、TLE2021运算放大器,通过信号处理模块对采集的被测信号进行放大,再用数据处理模块进行信号的软件线性化处理,最后通过V/I变换模块把反映温度的线性变化信号调制成电压信号后,转换成相应的电流信号（0～16mA）,加上系统的静态电流4mA,形成4～20mA的电流信号通过二线电流线输出。软件采用查表法和计算法结合的插值法。该装置精度可以保证在0.1%,可靠性较好,电路简单,成本低,体积小,生产调试方便。     

基于时频分析法的高速列车轨道电路故障诊断

针对现有高速列车轨道电路故障诊断方法大多采用电压电流信号有效值,没有充分利用其丰富的频域信息的问题,为提高轨道电路故障诊断系统的性能,提出基于电压电流实时信号时频分析的故障诊断方法.基于短时傅里叶变换(Short-Time Fourier Transform,STFT)生成频谱特征;根据可分性准则进行特征频带选择;采用支持向量机(Support Vector Machine,SVM)进行故障特征分类.基于现场数据的试验结果表明该方法有效.     

蓄电池恒流放电容量监测仪的电路设计

蓄电池恒流放电容量监测仪以单片机为核心,以PTC热敏电阻为放电负载;采用PWM技术控制电流恒定,实时监测放电电池的电流电压;采用大电流恒流放电方法,对蓄电池进行活化处理延长寿命。由ATmega128单片机、电源、存储器及时间芯片组成基础电路,由触摸屏、LCD显示模块、数据采集电路、PWM信号驱动电路组成显控驱动电路,监测仪则由二者共同构成。介绍了硬件构成与电路设计的思路。     

Boost功率因数校正器中输入电流波形失真分析与抑制

讨论了平均电流控制的Boost功率因数校正器中输入电流波形失真的机理,从理论上推导了前馈电压和输出电压中二次谐波电压对电流基准信号产生的影响,对前馈滤波器和电压反馈回路控制参数的设计进行了详细的讨论,采用控制芯片UC3854制作了一台输出功率为2000W的原理样机,通过原理样机输入电流波形的频谱分析,验证了分析方法和参数设计的正确性。     

EDA技术在数字系统设计分析中的应用

介绍EDA技术的特点,发展历程和发展趋势,以MAX+plusII开发系统为平台,以高密度可编程逻辑芯片CPLD为设计载体,采用层次化的设计方法,设计一个交通信号控制电路,从中可体现出数字系统的硬件设计向软件化方向发展的新思路。     

基于微悬臂梁的生化传感器

由微机械加工技术和集成电路工艺制作的微悬臂梁,通过在其表面修饰以生化敏感层,能将电、热、应力和化学等信号变化转换成一个机械响应,配合以信号采集电路和测量系统,能够达到很高的灵敏度和精度。回顾微悬臂梁作为传感器的发展历程,介绍悬臂梁的工作原理,微梁的激励、检测方法以及基于微悬臂梁阵列传感器的优点,总结了世界上硅基微悬臂梁生化传感器的最新动态,并且展望微悬臂梁传感器这一新领域的应用前景。     

三值组合电路的冒险分析

本文首先讨论了基于函数与／或表示形式的三值组合电路中的竞争冒险现象，提出应用代数法与Ｋ图法等二种分析与消除竞争冒险的技术。其次，本文分析了另一类多值电路中所固有的冒险现象－渡越冒险，指出它们属于一种电路的正常反应，但可采用快变信号与负载电容等方法加以抑制。     

An automatic netlist-to-schematic generator

The N2S schematic generator, which uses a variable-ordering technique in the initial placement phase and simple heuristics in the final placement phase, is described. Its channel-routing techniques result in signal routing with minimal crossovers. The authors demonstrate the efficiency of N2S by applying it to a set of benchmark sequential circuits     

衬底触发层叠式NMOS实现混合I/O静电保护机制研究

衬底触发技术可以大幅度提高大尺寸NMOS器件的ESD级别.将衬底触发技术融合到层叠式NMOS器件中来产生衬底触发层叠式NMOS器件,理论分析结果表明衬底触发技术可以提高混合电压I/O电路中层叠式NMOS器件的ESD稳健性,基于0.35μm CMOS工艺的模拟结果表明应用带有衬底触发技术的层叠式NMOS器件的HBM模型ESD级别提高约60%,这就验证了衬底触发设计对提高混合电压I/O电路的ESD级是有效的.     

Wafer-scale integration using restructurable VLSI

Results from a restructurable very large scale integration (RVLSI) program show the viability of using a laser to restructure wafer-scale circuits for customization and defect avoidance. Wafer-scale circuits are built with a standard integrated circuit fabrication process when the diffused-link restructuring device is used. Nine wafer-scale systems that have been built using the RVLSI technique are described. It is shown that the laser interconnection process has high yield and provides the high reliability of monolithic circuitry. The technology is well suited to signal processing systems, which characteristically use many replications of a small number of circuits and often have modest interconnection requirements     

Modeling of dispersive microwave FET devices using a quasi-static approach

In the design of active microwave circuits nonlinear device models are of great importance to allow one to predict the reliability of circuit performance. This article reflects our experimental approach in nonlinear FET modeling. Consistent bias-dependent model elements of the FET small-signal equivalent circuit are obtained by a recently developed unique multibias extraction procedure which permits the reduction of the nonlinear analysis to the inner part of a FET device. A dispersive nonlinear FET model with current and charge sources being integral functions of the bias-dependent small-signal model parameters is proposed. A bias-dependent difference transconductance and difference channel conductance are introduced as relevant dispersion parameters. The proposed nonlinear FET model is verified on the basis of our signal waveform measurement technique using combined frequency- and time-domain signal detection.     

PIC32MX单片机的无同步时钟电路HBS通信设计

家庭总线系统(HBS,Home Bus System)是商用空调控制领域应用最广泛的总线通信方式.该方式通常需要一个同步时钟信号对原有信号进行调制,最终实现接线端子的无极性连接.本文选用的PIC32 MX单片机没有同步时钟 I/O口,并且在无模拟外部同步时钟电路的情况下,使用异步接收同步无调制发送的方式实现了 HBS通信,解决了主芯片选用限制问题.由于此系列单片机同步和异步串行通信的收发均可单独配置,所以此种方式并不占用多余的 I/O口.     

Microfluidic integrated circuits for signal processing using analogous relationship between pneumatic microvalve and MOSFET

In this paper, a new concept and potential demonstration of functional microfluidic integrated circuits using MEMS technology are presented. The fluidic integrated circuits were constructed utilizing analogous relationship between MOSFET and pneumatic microvalve with a diaphragm structure. The signal transmitted through the circuit is the fluidic signal, that is, the pressure or the flow-rate of the fluid. The pneumatic microvalve in this study is expressed by small-signal equivalent model similar to that of a MOSFET. Small signal behavior of microfluidic integrated circuits can be expected using the model, if the parameters in the model are extracted properly from fabricated microvalves. As an example of a fluidic circuit, pressure inverting amplifiers including integrated two microvalves were fabricated and evaluated. As a result, they showed sharp pressure transfer curves similar to MOS inverter circuits. A maximum pressure gain of 32.0 dB was obtained, and it can be used for pressure amplification in analog applications. In addition, they can be used as pressure inverter logic circuits for digital applications. Although the theory and design environment of the new microvalve circuit technology have not been established yet, multifunctional fluidic analog and digital circuits can be realized for special application fields different from electronic integrated circuits.     

LVDS高速在I／O接口单元的设计研究

LVDS高速I/O接口单元是减小当前CMOS工艺芯片内外速度差异的重要电路,本文郑重分析了几种LVDSI/O接口单元的基本电路结构及其工作原理,并同时给出了用HSPICE工具进行模拟验证的结果。