Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal MODELs are built for the components. Thermal performance of thecircuit and the temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上传时间： 2013-11-16
上传用户：萍水相逢
Hyperlynx仿真应用:阻抗匹配.下面以一个电路设计为例，简单介绍一下PCB仿真软件在设计中的使用。下面是一个DSP硬件电路部分元件位置关系(原理图和PCB使用PROTEL99SE设计)，其中DRAM作为DSP的扩展Memory(64位宽度，低8bit还经过3245接到FLASH和其它芯片)，DRAM时钟频率133M。因为频率较高，设计过程中我们需要考虑DRAM的数据、地址和控制线是否需加串阻。下面，我们以数据线D0仿真为例看是否需要加串阻。模型建立首先需要在元件公司网站下载各器件IBIS模型。然后打开Hyperlynx,新建LineSim File(线路仿真—主要用于PCB前仿真验证)新建好的线路仿真文件里可以看到一些虚线勾出的传输线、芯片脚、始端串阻和上下拉终端匹配电阻等。下面，我们开始导入主芯片DSP的数据线D0脚模型。左键点芯片管脚处的标志，出现未知管脚，然后再按下图的红线所示线路选取芯片IBIS模型中的对应管脚。 3http://bbs.elecfans.com/ 电子技术论坛 http://www.elecfans.com 电子发烧友点OK后退到“ASSIGN MODELs”界面。选管脚为“Output”类型。这样，一样管脚的配置就完成了。同样将DRAM的数据线对应管脚和3245的对应管脚IBIS模型加上(DSP输出，3245高阻，DRAM输入)。下面我们开始建立传输线模型。左键点DSP芯片脚相连的传输线，增添传输线，然后右键编辑属性。因为我们使用四层板，在表层走线，所以要选用“Microstrip”，然后点“Value”进行属性编辑。这里，我们要编辑一些PCB的属性，布线长度、宽度和层间距等，属性编辑界面如下：再将其它传输线也添加上。这就是没有加阻抗匹配的仿真模型(PCB最远直线间距1.4inch，对线长为1.7inch)。现在模型就建立好了。仿真及分析下面我们就要为各点加示波器探头了，按照下图红线所示路径为各测试点增加探头：为发现更多的信息，我们使用眼图观察。因为时钟是133M，数据单沿采样，数据翻转最高频率为66.7M，对应位宽为7.58ns。所以设置参数如下：之后按照芯片手册制作眼图模板。因为我们最关心的是接收端(DRAM)信号，所以模板也按照DRAM芯片HY57V283220手册的输入需求设计。芯片手册中要求输入高电平VIH高于2.0V，输入低电平VIL低于0.8V。DRAM芯片的一个NOTE里指出，芯片可以承受最高5.6V，最低-2.0V信号(不长于3ns)：按下边红线路径配置眼图模板：低8位数据线没有串阻可以满足设计要求，而其他的56位都是一对一，经过仿真没有串阻也能通过。于是数据线不加串阻可以满足设计要求，但有一点需注意，就是写数据时因为存在回冲，DRAM接收高电平在位中间会回冲到2V。因此会导致电平判决裕量较小，抗干扰能力差一些，如果调试过程中发现写RAM会出错，还需要改版加串阻。
上传时间： 2013-12-17
上传用户：debuchangshi
The ICA/BSS algorithms are pure mathematical formulas, powerful, but rather mechanical procedures: There is not very much left for the user to do after the machinery has been optimally implemented. The successful and efficient use of the ICALAB strongly depends on a priori knowledge, common sense and appropriate use of the preprocessing and postprocessing tools. In other words, it is preprocessing of data and postprocessing of MODELs where expertise is truly ne
标签： mathematical algorithms mechanical procedures
上传时间： 2015-03-31
上传用户：silenthink
基于模型聚类算法的matlab实现 This does the entire MB Clustering given a set of data. It only does the 4 basic MODELs, unequal-unknown priors. It returns the BESTMODEL based on the highest BIC.
标签： does Clustering the matlab
上传时间： 2015-04-29
上传用户：playboys0
MATLABThe CD-ROM accompanying this book contains MATLAB® M-files (MATLAB language source code) and Simulink® block diagram MODELs for designing, implementing and testing control systems.
标签： MATLAB accompanying MATLABThe contains
上传时间： 2013-11-26
上传用户：yyyyyyyyyy
eForth is a small portable Forth design for a wide range of microprocessors. This is the first implementation for 8086. As machine dependency is consolidated into 31 code words, moving eForth to other CPU s will be much less of a chore comparing to other Forth MODELs.
标签： microprocessors portable eForth design
上传时间： 2014-01-25
上传用户：从此走出阴霾
matlab矩阵处理例程。A matrix processor, Matx_Proc() is developed which can be used to process and edit matrices and state space MODELs, and perform various kind of matrix analysis in a visible way.
标签： Matx_Proc developed processor process
上传时间： 2015-06-23
上传用户：Breathe0125
The Fortran 90 Handbook is a definitive and comprehensive guide to Fortran 90 and its use. Fortran 90, the latest standard version of Fortran, has many excellent new features that will assist the programmer in writing efficient, portable, and maintainable programs. The Fortran 90 Handbook is an informal description of Fortran 90, developed to provide not only a readable explanation of features, but also some rationale for the inclusion of features and their use. In addition, “MODELs” give the reader better insight as to why things are done as they are in the language.
标签： Fortran comprehensive definitive and
上传时间： 2015-06-29
上传用户：aa17807091
The Fortran 90 Handbook is a definitive and comprehensive guide to Fortran 90 and its use. Fortran 90, the latest standard version of Fortran, has many excellent new features that will assist the programmer in writing efficient, portable, and maintainable programs. The Fortran 90 Handbook is an informal description of Fortran 90, developed to provide not only a readable explanation of features, but also some rationale for the inclusion of features and their use. In addition, “MODELs” give the reader better insight as to why things are done as they are in the language.
标签： Fortran comprehensive definitive and
上传时间： 2015-06-29
上传用户：teddysha
The Fortran 90 Handbook is a definitive and comprehensive guide to Fortran 90 and its use. Fortran 90, the latest standard version of Fortran, has many excellent new features that will assist the programmer in writing efficient, portable, and maintainable programs. The Fortran 90 Handbook is an informal description of Fortran 90, developed to provide not only a readable explanation of features, but also some rationale for the inclusion of features and their use. In addition, “MODELs” give the reader better insight as to why things are done as they are in the language.
标签： Fortran comprehensive definitive and
上传时间： 2013-12-22
上传用户：xinzhch
