厚膜压力传感器温度补偿用厚膜热敏电阻的研制

对过渡金属氧化物CoO、MnO、NiO厚膜热敏电阻进行了掺杂改进和重复性烧结试验,可较好地实现厚膜热敏电阻与厚膜力敏电阻一体化的温度补偿。     

不同特性材料制备的温补衰减器的电性能研究

采用具有相同正温度系数的普通电阻浆料及热敏电阻浆料,分别配合同一种具有负温度系数的热敏电阻浆料,在质量分数为96%的Al_2O_3陶瓷基板上制备p型电阻网络结构的温度补偿衰减器。测试结果表明,在25℃下,DC~12.4 GHz的频率范围内,正温度系数的热敏电阻浆料与负温度系数的热敏电阻浆料制备的衰减量为3 dB、衰减量温度系数为–0.009 dB/dB/℃的温补衰减器样品,其高频性能更好。     

基于叠加型的温度补偿电流源的设计

提出了一个新型电流叠加型的温度补偿电流源的设计,通过新增加一条电流支路,对温度特性进行优化,使用简单的结构,达到了很好的温度特性和电源电压调整率。使用XFAB公司的0.6μm CMOS工艺模型,Cadence模拟验证结果表明,在-40~135℃范围内,温度系数为16ppm/℃;电源电压抑制比为77.2dB。该方案已经应用于AC/DC转换器芯片。     

AC/DC开关电源中温度补偿电流源的设计

提出了一种新型电流叠加型温度补偿技术,设计出用于AC/DC开关电源芯片的温度补偿电流源.在传统正负温度系数电流叠加的基础上,通过增加一条电流支路,对温度特性进行优化,使用简单的结构得到了很好的温度特性和电源电压调整率.使用XFAB公司的0.6 μm CMOS工艺模型,Cadence模拟验证结果表明,在-40～135℃范围内温度系数为16×10-6/℃.该方案已经应用于AC/DC开关电源芯片.     

全CMOS温度补偿电流源

本文采用迁移率与阈值电压互相补偿的原理,实现了一个与温度无关的电流源。该电流源完全与标准的CMOS工艺相兼容。测试结果显示,在温度范围为-20℃到110℃之内,电流源的温度系数小于290ppm/℃。     

指数型温度补偿BiCMOS带隙基准电压源设计

利用双极型管电流增益的温度特性,采用UMC0.6μm BiCMOS工艺设计了一款指数型温度补偿BiCMOS带隙基准电压源。测试结果表明:温度在10°C～100°C之间变化,带隙基准电压随温度变化最大偏移为2.5mV;电源电压在2.5～5.0V之间变化,带隙基准电压随电源电压直流变化最大偏移为0.95mV。该带隙基准电压具有较高的温度稳定性和电压稳定性。     

一个具有温度补偿特性的无电阻CMOS电流基准源

A resistorless CMOS current reference is presented.Temperature compensation is achieved by subtracting two sub-currents with different positive temperature coefficients.The circuit has been implemented with a Chartered0.35μm CMOS process.The output current is 1.5μA,and the circuit works properly with a supply voltage down to 2 V.Measurement results show that the temperature coefficient is 98 ppm/℃,and the line regulation is 0.45%/V.The occupied chip area is 0.065 mm~2.     

一种低温度漂移曲率补偿带隙基准源设计

针对传统带隙基准源无法补偿高阶温度项导致温度系数较差的问题,提出了一种高阶曲率补偿电路。电路利用VBE线性补偿原理,使用特定的电路结构产生与双极型晶体管基极-发射极电压开口曲率相反方向的补偿电压,达到降低基准电压高阶温度项的目的。电路基于SMIC 0.18μm工艺进行流片验证,测试结果表明,温度由-40℃变化到125℃时,使用曲率补偿后带隙基准电压的温度系数由14.3×10^-6/℃降低到了3.18×10^-6/℃。     

一种具有温度补偿的时钟振荡器设计

介绍了一种采用0.35μm CMOS工艺制作的具有温度补偿的时钟振荡器电路。从环形振荡器的基本原理出发,基于对CMOS工艺各种非理想性因素的分析,提出一种新型的工艺补偿电路,减小振荡器偏置电流随阈值电压的漂移;在延迟单元的设计中,引入NMOS交叉耦合对组成的交流负阻抗来进一步补偿PMOS迁移率随温度的变化,从而有效抑制输出频率随温度的变化。该振荡器电路用于MEMS加速度计读出电路芯片。样品电路测试结果表明,在-20~100℃温度范围内,时钟振荡器的频率仅变化38kHz。     

CMOS偏置电流基准源的两级温度补偿方法

提出了一种利用分支电流的正、负温度系数(TC)进行两级温度补偿的新型设计方法,并用标准CMOS工艺实现了一个20μA电流偏置基准源。其结构简单,各参数匹配要求较低,且具有多项参数的设计灵活性,详细探讨了两级温度补偿参数间的各种关系,并给出了相应的解析表达式。电路还包含自启动电路,可避免零电流工作状态的出现。经特许半导体公司0.35μm 2P4M工艺流片,芯片测试结果表明,在0~120℃范围内,其温度系数达35.63 ppm/℃。     

热电偶温度测试技术原理及应用分析

文章论述了温度测量原理,热电偶测温时的冷端处理方法,并分析了热电偶测量温度时的误差来源,并提出了合理的减小误差的方法,为温度测量提供有效参考。     

APD阵列芯片偏置电压温度补偿系统设计与实现

为使APD阵列芯片在不同温度下保持较为恒定的增益,设计反向偏压自动温度补偿系统。采用STM32微处理器对热敏电阻分压采样和A/D转换后计算获得阵列芯片工作温度,根据工作温度求解出合适的反向偏压值,再通过调节数字电位器控制高压模块输出解算得到的反向偏压至APD阵列芯片。采用Matlab仿真方法获取匹配电阻的阻值避免了繁琐的数学推导。应用μC/OS嵌入式操作系统实现多任务程序设计,且任务间采用消息邮箱通信,提高了软件运行的稳定性和可靠性。测试结果表明,使用该温度补偿系统的5×5 APD阵列芯片的每个通道都能在不同温度下保持本通道输出信号幅度基本恒定,证明了系统的有效性和实用性。     

The application of gallium arsenide integrated circuit technologyto the design and fabrication of future generation digital signalprocessors: promises and problems

The development of gallium arsenide digital integrated circuit technology has progressed rapidly during the past decade. It is argued that in order to derive the maximum benefit from this technology as it is inserted into next-generation signal and data processors, all aspects of the design, assembly, testing, and maintenance of the systems will have to be considered synergistically. Salient issues which must be considered in the implementation of these advanced digital processors are reviewed, including the effects of system, logic board, chip layout, and packing constraints on memory layout, logic design, and arithmetic implementation     

Optical-to-electrical wavelength demultiplexing detector: design,fabrication, and analysis

An optical-to-electrical wavelength demultiplexing detector has been fabricated using a short length of twin-core optical fiber and an integrated bi-cell detector. The twin-core fiber splits 1325 and 1535 nm input signals onto different output cores, thus directing each demultiplexed channel onto the spatially separated active areas of the bi-cell. We discuss the design, fabrication, and post-tuning techniques used to successfully demonstrate the wavelength demultiplexing functionality of the device and present some preliminary results from an assembled laboratory prototype     

A novel principle of magnetic flux compensation and its application in power systems

A novel principle of magnetic flux compensation of a linear transformer is proposed. The current of the primary winding is detected and multiplied by a compensation coefficient to get a reference current, which is tracked by a voltage source inverter to produce a compensation current. This compensation current is injected inversely in phase into the secondary winding. According to the law of superposition and the transformer's voltage equations, the main magnetic flux in the transformer and the equivalent impedance of the primary winding correlate linearly with the current compensation coefficient, and this equivalent impedance varies linearly with the current compensation coefficient. This new principle can be widely applied in power systems, such as series hybrid active power filter, fault current limiter, continuously controllable reactor, arc suppression coil and power system load flow control, and many FACTS devices can be implemented in terms of the new principle. A current control scheme is analysed. The theory is validated by experimental results, and some new devices based on the principle are discussed.     

Passive Optical Networks (PONs): Past, present, and future

Optical access solutions have attracted the attention of researchers from both academia and industry for a long time. In the past these solutions were not cost effective for service-provider deployment. This situation has been changing over recent years. Passive Optical Networks (PONs) represent one of the most attractive optical access-network solutions. In this paper, we examine the history of PONs, investigate their current status, and explore their future opportunities. The focus of our review is on PON standards and on deployment trends.     

A smart microrobot on chip: design, identification, and control

This paper deals with the microrobot on chip (MOC) concept which corresponds to the development of compact, inexpensive, and easily "plug and use" microrobotic components (as it is the usual case with electronic chips). A first prototype of a 6 degrees-of-freedom (DOF) piezoelectric micromanipulator MOC (MMOC) illustrates this concept: one scanning piezostage can move the gripper in x-y axes and the piezoelectric microgripper itself has two y-z DOF per finger. An embedded optical fiber connected to a CCD camera and a force self-sensing system allowing force feedback. The first prototype of MMOC is electrically and mechanically connected to a smartcard reader. In order to be able to manipulate safely and accurately micro-objects, a force/position closed-loop controller is proposed taking into account the static and dynamic behavior of the microgripper. Hysteresis compensation is obtained through Preisach model and then an adaptive inverse control method is employed for open-loop control strategy. Numerical and experimental results which validate the theoretical developments are presented.     

Survey of blockchain:principle,progress and application

Blockchain is a kind of distributed ledger technology that upgrades to a complete storage system by adding logic control functions such as intelligent contracts.With the changes of its classification,service mode and application requirements,the core technology forms of Blockchain show diversified development.In order to understand the Blockchain ecosystem thoroughly,a hierarchical technology architecture of Blockchain was proposed.Furthermore,each layer of blockchain was analyzed from the perspectives of basic principle,related technologies and research progress in-depth.Moreover,the technology selections and characteristics of typical Blockchain projects were summarized systematically.Finally,some application directions of blockchain frontiers,technology challenges and research prospects including Smart Cities and Industrial Internet were given.     

Multi-LED package design, fabrication and thermal analysis

An ultra-thin multi-LED package is designed,manufactured and its thermal performance is characterized. The objective of this study is to develop an efficient thermal modelling approach for this system which can be used for optimization of the thermal-performance of future ultra-thin designs.A high-resolution thermal imaging camera and thermocouples were used to measure the temperature distribution of the multi-LED package and the LED-die temperature for different operating powers.Finally,we compare the thermal measurements with the finite element simulation results.It is concluded that the modelling approach can assist in the thermal optimization of future multi-LED package designs.     

Current reliability issues and future technologies for systems on silicon – processes, circuits, chip architecture, and design

The progress of silicon technology is opening the era of “systems on silicon” in which a large-scale memory, a CPU, and other logic macros will be integrated on a single chip. These kinds of chips, called system LSIs, have an especially promising future in mobile and multimedia applications but face inherent technical problems related to the reliability of ultrathin oxide film, conflict in the processing of different components, increased gate and subthreshold leakage currents, memory bottlenecks, and design complexity. This paper reviews the system LSIs and then introduces related technologies in processing, circuits, chip architecture, and design. It also discusses the influence of the system LSIs on business strategies.