FPGA片内PLL电磁抗扰度的热应力效应测试分析

针对集成电路(IC)在复杂物理环境中的电磁抗扰度漂移问题,研究了环境热应力对基于供电网络传导耦合的现场可编程逻辑门阵列(FPGA)内嵌锁相环(PLL)电路电磁抗扰度的影响。分析典型FPGA片内PLL的功能原理及电磁干扰机理;将环境热应力干扰因素引入PLL电磁抗扰度测试研究中,设计基于电磁干扰直接功率注入(DPI)与热应力耦合的抗扰度测试平台;测试分析了在20～110℃热应力范围内,电磁干扰分别通过1.2 V、2.5 V和IC地电源网络注入片内PLL时,其电磁抗扰度特性变化。结果表明,当片内PLL功能单元受到不同注入路径的电磁干扰时,其在不同频段的电磁抗扰度变化趋势基本一致;考虑热应力因素影响时,片内PLL的电磁抗扰度特性会发生明显漂移,且当锁相环的2.5 V工作电压受到电磁-热复合应力干扰时,PLL的电磁抗扰度最弱,热应力干扰因素加剧了其抗扰度的漂移。     

电磁兼容抗扰度试验的探讨

电磁兼容性测试是对设备在电磁环境中不对其他设备产生电磁干扰、并能符合要求运行的能力进行测试。文章介绍了电磁兼容抗扰度试验主要针对的内容和项目,对影响电磁兼容的因素进行分析,总结了电磁兼容抗扰度试验的重要作用,对提高电子、电气产品的电磁兼容度提了一些建议。     

汽车电磁抗扰度技术标准介绍

介绍了汽车电磁抗扰度的最新国家标准。汽车电磁抗扰性能关系到车辆运行的安全可靠性，提高汽车电磁抗扰性能的关键在于电磁抗扰度技术要求及试验技术。     

IEC 62132抗扰度测试方法研究

介绍关于集成电路电磁抗扰度测量方法的国际标准IEC 62132。对标准给出的四种方法——TEM小室和宽带TEM小室法、大电流注入法、射频功率直接注入法及工作台法拉第笼法的测试原理,试验布置及测试过程中的注意事项进行了说明,列出四种方法的不同点,以帮助测试人员根据不同的IC特点选择相应的试验方法。     

汽车电磁抗扰度技术标准介绍

介绍了汽车电磁抗扰度的最新国家标准.汽车电磁抗扰性能关系到车辆运行的安全可靠性,提高汽车电磁抗扰性能的关键在于电磁抗扰度技术要求及试验技术.     

汽车电磁抗扰度技术标准介绍

介绍了汽车电磁抗扰度的最新国家标准。汽车电磁抗扰性能关系到车辆运行的安全可靠性,提高汽车电磁抗扰性能的关键在于电磁抗扰度技术要求及试验技术。     

NEBS认证——辐射抗扰度和传导抗扰度

介绍了NEBS认证对待认证设备抗扰度的要求,包括设备的辐射抗扰度要求和设备对外端口的传导抗扰度要求。辐射抗扰度除了规定频率范围内的测试外,还要求在美国的一些专用频点及设备的工作频点上进行测试。传导抗扰度要求用电流注入法进行测试,不能用电压耦合法测试。传导抗扰度测试除了规定频率范围内的测试外,也要求在设备的工作频点上进行测试。     

欧盟对影音产品电磁抗扰度的新要求

根据欧盟的法规,欧盟范围内销售的电子电器产品需满足相关的技术规范,其中包括电磁兼容指令(89/336/EEC)的要求.因此,在欧盟销售的影音产品其电磁干扰的发放必须受到限制,同时也必须具备一定的电磁抗扰度,以满足电磁兼容指令的要求.对影音产品电磁抗扰度测试方法与技术要求的标准为EN 55020.2005年4月1日起,EN 55020的1994版及其修正版本将被2002版及其修正版取代而作废.     

汽车电子辐射抗扰度测试用带状线的研制

根据汽车电子电器组件的辐射抗扰度测试的要求,研制了一套带状线测试装置.利用仿真软件对带状线装置进行结构优化设计,分析了该带状线装置的场强分布.研制的带状线装置的特性阻抗为50 Ω,在300 kHz～400 MHz的频率范围内,电压驻波比(VSWR)小于1.25.当注入20W的信号功率时,带状线装置的测试区最大能产生200 V/m的电场强度.     

某电气系统电磁抗扰性分析及解决方案

为了查找某电气系统电磁抗扰性薄弱环节,对该电气系统的关键接口电缆进行了电磁兼容性测试.对查找出的薄弱环节,从电磁兼容三要素出发,分析干扰传播路径,对其采取屏蔽、接地加固措施.经试验验证措施有效,达到系统间兼容工作的目的.     

应用加热软化和应力效应的激光加工技术

常规激光加工技术多是利用高温使材料熔化或气化而达到加工目的,但是往往需要克服在激光加热过程中引起的材料软化和热应力.探讨了利用激光加热引起的软化和热应力效应进行加工的可行性,主要研究了激光加热辅助切削(LAM)技术和激光加热弯曲三维成形技术等非常规激光加工技术,着重探讨了LAM陶瓷材料的温度场变化、切屑形态和加工表面形...     

基于信号完整性的LCDs抗电磁干扰性能提升

针对电磁干扰下LCDs显示异常问题,基于信号传输完整性理论,提出提升LCDs抗电磁干扰能力方法,旨在提升LCDs在复杂电磁环境下的显示质量和电磁兼容性能。首先,基于信号完整性,分析电磁干扰下显示异常机理,分析画面异常原因。其次,基于自适应信号品质增强模型、信号传输路径优化和LCDs专用复合结构型吸波材料3个方面,总结LCDs抗电磁干扰性能提升的方案。最后,基于电磁仿真和产品实测,验证3种方案改善效果。仿真和实验结果表明本文所述改善方案可有效提高液晶显示面板的抗电磁干扰性能,提高LCDs产品电磁兼容性能。     

Estimation of the noise immunity of immitance logic elements

The noise immunity of immitance logic elements (ILEs) realized on the basis of a transistor generalized immitance converter (GIC) is analytically estimated. It is shown that this estimate is determined by the effect of static interferences (temperature and supply voltage changes), high-frequency interferences (reference oscillation power and frequency changes), and immitance interferences (changes of the real and imaginary components of the immitance to be converted and changes of internal interferences related with the GIC potential instability). It is suggested to use the relative noise immunity coefficients for the immitance levels of logic 0-γ _C , and logic 1-γ _L , for analytical estimation of the ILE noise immunity. The admissible range of variation of these immitance levels are 0 < γ _C < 1 and 0 < γ _L < 1. The noise immunity is quantitatively estimated. As a result, it is found that, within the reference frequency 0.4–1.5 GHz, an ILE’s reserve of the noise immunity to the instability of the imaginary component of the high-Q input immitance exceeds 80% and that the noise immunity reserve is reduced by no more than 5% when the supply voltage changes by 30% and when the temperature changes by 40%.     

CSP结构的热应力分析

利用ansys软件通过仿真得到了在稳态情况下的CSP结构热场分布,在此基础上,把稳态情况下的热场分布作为温度载荷施加到模型上,得到了CSP结构热应力分布,这对集成电路热设计方案的选择,尤其对提高大功率集成电路的可靠性具有重要意义.     

基于通用可编程IO口的摄像头总线接口设计与实现

该文提出了一种基于通用可编程IO口(GPIO)的摄像头总线接口(CAMIF)设计方案,通过普通的GPIO口来实现对Camera的数据采集,然后通过软件对采集来的数据进行处理,整个过程全部依赖于软件,从而摆脱了对硬件CAMIF的依赖,并由此实现廉价的拍照方案。     

Increasing the immunity to electromagnetic interferences of CMOS OpAmps

This paper presents the successful design of a CMOS operational amplifier with enhanced immunity to electromagnetic interferences. Thanks to its strongly symmetrical topology, the amplifier exhibits an intrinsic robustness to interferences arising from a wide class of sources. Such a scheme, for the first time in the authors' knowledge, proves the effectiveness of symmetrical topologies to minimize the effects of electromagnetic interferences in operational amplifiers. The amplifier architecture is based on 2 identical stages: 2 fully differential source cross-coupled amplifiers with active loads. The circuit was fabricated in a 0.8 /spl mu/m n-well CMOS technology (AMS CYE process). Experimental results, in terms of EMI immunity, are presented and compared with a commercial amplifier. They show a low susceptibility to EMI conveyed both to the input and the power pins. The EMI effects on the proposed amplifier are reduced by more than one order of magnitude, compared to a commercial amplifier. Furthermore the amplifier overall measured performances are provided along with the corresponding simulation results.     

Modulation of mammalian immunity by electromagnetic radiation

There have been reports that electromagnetic radiation (EMR) alters the function of the immune system; however, these reports are often contradictory. This review reexamines the literature and attempts to evaluate the data on potential mechanisms of interaction of EMR on mammalian immune function. This report concludes that there is no convincing evidence that EMR effects on the human immune system are a health hazard. It was suggested by some authors that long-term EMR exposure may impair immune surveillance, and hypothetically thus facilitate tumor growth. Additional research is needed to prove or disprove this hypothesis. Available data indicate that EMR exposure does not affect the ability of cells of the immune system to respond to a subsequent challenge. However, the time-course and magnitude of the response may be affected by exposure following stimulation. Research to date provided evidence that at least at some frequencies and/or amplitude and pulse modulations, the site of primary interaction of EMR is at the cell membrane. However, it was shown that one specific response, the increase in B complement-receptor positive lymphocytes (Cr+) in the mouse is under genetic control by a single gene localized on chromosome 5. It is suggested that cells of the immune system are a convenient model for further studies on mechanisms of EMR interaction with living systems. Future research should be directed at exploring beneficial medical applications of EMR modulation of immune responses.     

The effect of patterns on thermal stress during rapid thermalprocessing of silicon wafers

The presence of patterns can lead to temperature nonuniformity and undesirable levels of thermal stress in silicon wafers during rapid thermal processing (RTP). Plastic deformation of the wafer can lead to production problems such as photolithography overlay errors and degraded device performance. In this work, the transient temperature fields in patterned wafers are simulated using a detailed finite-element-based reactor transport model coupled with a thin film optics model for predicting the effect of patterns on the wafer radiative properties. The temperature distributions are then used to predict the stress fields in the wafer and the onset of plastic deformation. Results show that pattern-induced temperature nonuniformity can cause plastic deformation during RTP, and that the problem is exacerbated by single-side heating, increased processing temperature, and increased ramp rate. Pattern effects can be mitigated by stepping the die pattern out to the edge of the wafer or by altering the thin film stack on the wafer periphery to make the radiative properties across the wafer more uniform     

场路结合法分析设备电磁辐照效应

电子设备机壳内部往往会内置多层印制电路板,外界电磁干扰很可能通过设备的外接导线进入设备内部进而对电路板造成损坏。针对这种情况,采用全波分析法获得受干扰设备的相关参数,利用该参数建立等效源模型;等效电路法分析内部电路板上电路的电磁特性。通过全波分析法和等效电路法相结合的方式来分析外界电磁干扰进入设备内部时所造成的影响,为处于高频电磁干扰环境中的电路工作特性研究提供新思路和参考。