·SystemVerilog is a rich set of extensions to the IEEE 1364-2001 Verilog Hardware Description Language (Verilog HDL). These extensions address two major aspects of HDL-based design. First, modeling ver
标签： nbsp SystemVerilog Design for
上传时间： 2013-07-14
上传用户：ainimao
在PC机上运行cadence需要先运行命令:source filename,此处filename指.cshrc,或其他具有该文件内容但名字不同的文件,该文件必须有set DISPLAY 本机IP:0.0 语句,同时应将其他雷同设置封住.可以先从工作站上下载.cshrc文件,然后用notepad修改显示设置相,不可用其他编辑器,否则文本文件格式会不一样.记住,必须将显示器设置为256色.
上传时间： 2013-09-05
上传用户：超凡大师
Abstract: Alexander Graham Bell patented twisted pair wires in 1881. We still use them today because they work so well. In addition we have the advantage ofincredible computer power within our world. Circuit simulators and filter design programs are available for little or no cost. We combine the twisted pair and lowpassfilters to produce spectacular rejection of radio frequency interference (RFI) and electromagnetic interference (EMI). We also illustrate use of a precision resistorarray to produce a customizable differential amplifier. The precision resistors set the gain and common mode rejection ratios, while we choose the frequencyresponse.
上传时间： 2014-11-26
上传用户：Vici
Abstract: Using a DAC and a microprocessor supervisor, the system safety can be improved in industrial controllers, programmablelogiccontrollers (PLC), and data-acquisition systems. The analog output is set to zero-scale (or pin-programmable midscale) when amicroprocessor failure, optocoupler failure, or undervoltage condition occurs. A simple application is shown on how to implement thisfunction.
上传时间： 2013-10-17
上传用户：sjb555
Who has never experienced oscillations issues when using an operational amplifier? Opampsare often used in a simple voltage follower configuration. However, this is not the bestconfiguration in terms of capacitive loading and potential risk of oscillations.Capacitive loads have a big impact on the stability of operational amplifier-basedapplications. Several compensation methods exist to stabilize a standard op-amp. Thisapplication note describes the most common ones, which can be used in most cases.The general theory of each compensation method is explained, and based on this, specific
上传时间： 2013-10-28
上传用户：chenbhdt
比例控制(P)是一种最简单的控制方式。其控制器的输出与输入误差信号成比例关系。根据设备有所不同，比例带一般为2～10％(温度控制)。但是，仅仅是P 控制的话，会产生下面将提到的off set (稳态误差)，所以一般加上积分控制(I)，以消除稳态误差。
上传时间： 2014-07-21
上传用户：frank1234
ANALOG INPUT BANDWIDTH is a measure of the frequencyat which the reconstructed output fundamental drops3 dB below its low frequency value for a full scale input. Thetest is performed with fIN equal to 100 kHz plus integer multiplesof fCLK. The input frequency at which the output is −3dB relative to the low frequency input signal is the full powerbandwidth.APERTURE JITTER is the variation in aperture delay fromsample to sample. Aperture jitter shows up as input noise.APERTURE DELAY See Sampling Delay.BOTTOM OFFSET is the difference between the input voltagethat just causes the output code to transition to the firstcode and the negative reference voltage. Bottom Offset isdefined as EOB = VZT–VRB, where VZT is the first code transitioninput voltage and VRB is the lower reference voltage.Note that this is different from the normal Zero Scale Error.CONVERSION LATENCY See PIPELINE DELAY.CONVERSION TIME is the time required for a completemeasurement by an analog-to-digital converter. Since theConversion Time does not include acquisition time, multiplexerset up time, or other elements of a complete conversioncycle, the conversion time may be less than theThroughput Time.DC COMMON-MODE ERROR is a specification which appliesto ADCs with differential inputs. It is the change in theoutput code that occurs when the analog voltages on the twoinputs are changed by an equal amount. It is usually expressed in LSBs.
上传时间： 2013-11-12
上传用户：pans0ul
高速数字系统设计下载pdf:High-Speed Digital SystemDesign—A Handbook ofInterconnect Theory and DesignPracticesStephen H. HallGarrett W. HallJames A. McCallA Wiley-Interscience Publication JOHN WILEY & SONS, INC.New York • Chichester • Weinheim • Brisbane • Singapore • TorontoCopyright © 2000 by John Wiley & Sons, Inc.speeddigital systems at the platform level. The book walks the reader through everyrequired concept, from basic transmission line theory to digital timing analysis, high-speedmeasurement techniques, as well as many other topics. In doing so, a unique balancebetween theory and practical applications is achieved that will allow the reader not only tounderstand the nature of the problem, but also provide practical guidance to the solution.The level of theoretical understanding is such that the reader will be equipped to see beyondthe immediate practical application and solve problems not contained within these pages.Much of the information in this book has not been needed in past digital designs but isabsolutely necessary today. Most of the information covered here is not covered in standardcollege curricula, at least not in its focus on digital design, which is arguably one of the mostsignificant industries in electrical engineering.The focus of this book is on the design of robust high-volume, high-speed digital productssuch as computer systems, with particular attention paid to computer busses. However, thetheory presented is applicable to any high-speed digital system. All of the techniquescovered in this book have been applied in industry to actual digital products that have beensuccessfully produced and sold in high volume.Practicing engineers and graduate and undergraduate students who have completed basicelectromagnetic or microwave design classes are equipped to fully comprehend the theorypresented in this book. At a practical level, however, basic circuit theory is all thebackground required to apply the formulas in this book.
上传时间： 2013-10-26
上传用户：缥缈
Radio Frequency Integrated Circuit Design I enjoyed reading this book for a number of reasons. One reason is that itaddresses high-speed analog design in the context of microwave issues. This isan advanced-level book, which should follow courses in basic circuits andtransmission lines. Most analog integrated circuit designers in the past workedon applications at low enough frequency that microwave issues did not arise.As a consequence, they were adept at lumped parameter circuits and often notcomfortable with circuits where waves travel in space. However, in order todesign radio frequency (RF) communications integrated circuits (IC) in thegigahertz range, one must deal with transmission lines at chip interfaces andwhere interconnections on chip are far apart. Also, impedance matching isaddressed, which is a topic that arises most often in microwave circuits. In mycareer, there has been a gap in comprehension between analog low-frequencydesigners and microwave designers. Often, similar issues were dealt with in twodifferent languages. Although this book is more firmly based in lumped-elementanalog circuit design, it is nice to see that microwave knowledge is brought inwhere necessary.Too many analog circuit books in the past have concentrated first on thecircuit side rather than on basic theory behind their application in communications.The circuits usually used have evolved through experience, without asatisfying intellectual theme in describing them. Why a given circuit works bestcan be subtle, and often these circuits are chosen only through experience. Forthis reason, I am happy that the book begins first with topics that require anintellectual approach—noise, linearity and filtering, and technology issues. Iam particularly happy with how linearity is introduced (power series). In therest of the book it is then shown, with specific circuits and numerical examples,how linearity and noise issues arise.
上传时间： 2014-12-23
上传用户：han_zh
模块电源的电气性能是通过一系列测试来呈现的，下列为一般的功能性测试项目，详细说明如下： 电源调整率(Line Regulation) 负载调整率(Load Regulation) 综合调整率(Conmine Regulation) 输出涟波及杂讯(Ripple & Noise) 输入功率及效率(Input Power, Efficiency) 动态负载或暂态负载(Dynamic or Transient Response) 起动(Set-Up)及保持(Hold-Up)时间 常规功能(Functions)测试 1. 电源调整率 电源调整率的定义为电源供应器于输入电压变化时提供其稳定输出电压的能力。测试步骤如下：于待测电源供应器以正常输入电压及负载状况下热机稳定后，分别于低输入电压(Min)，正常输入电压(Normal)，及高输入电压(Max)下测量并记录其输出电压值。 电源调整率通常以一正常之固定负载(Nominal Load)下，由输入电压变化所造成其输出电压偏差率(deviation)的百分比，如下列公式所示： [Vo(max)-Vo(min)] / Vo(normal) 2. 负载调整率 负载调整率的定义为开关电源于输出负载电流变化时，提供其稳定输出电压的能力。测试步骤如下：于待测电源供应器以正常输入电压及负载状况下热机稳定后，测量正常负载下之输出电压值，再分别于轻载(Min)、重载(Max)负载下，测量并记录其输出电压值(分别为Vo(max)与Vo(min))，负载调整率通常以正常之固定输入电压下，由负载电流变化所造成其输出电压偏差率的百分比，如下列公式所示： [Vo(max)-Vo(min)] / Vo(normal) 3. 综合调整率 综合调整率的定义为电源供应器于输入电压与输出负载电流变化时，提供其稳定输出电压的能力。这是电源调整率与负载调整率的综合，此项测试系为上述电源调整率与负载调整率的综合，可提供对电源供应器于改变输入电压与负载状况下更正确的性能验证。 综合调整率用下列方式表示：于输入电压与输出负载电流变化下，其输出电压之偏差量须于规定之上下限电压范围内(即输出电压之上下限绝对值以内)或某一百分比界限内。 4. 输出杂讯 输出杂讯(PARD)系指于输入电压与输出负载电流均不变的情况下，其平均直流输出电压上的周期性与随机性偏差量的电压值。输出杂讯是表示在经过稳压及滤波后的直流输出电压上所有不需要的交流和噪声部份(包含低频之50/60Hz电源倍频信号、高于20 KHz之高频切换信号及其谐波，再与其它之随机性信号所组成))，通常以mVp-p峰对峰值电压为单位来表示。 一般的开关电源的规格均以输出直流输出电压的1%以内为输出杂讯之规格，其频宽为20Hz到20MHz。电源实际工作时最恶劣的状况(如输出负载电流最大、输入电源电压最低等)，若电源供应器在恶劣环境状况下，其输出直流电压加上杂讯后之输出瞬时电压，仍能够维持稳定的输出电压不超过输出高低电压界限情形，否则将可能会导致电源电压超过或低于逻辑电路(如TTL电路)之承受电源电压而误动作，进一步造成死机现象。 同时测量电路必须有良好的隔离处理及阻抗匹配，为避免导线上产生不必要的干扰、振铃和驻波，一般都采用双同轴电缆并以50Ω于其端点上，并使用差动式量测方法(可避免地回路之杂讯电流)，来获得正确的测量结果。 5. 输入功率与效率 电源供应器的输入功率之定义为以下之公式： True Power = Pav(watt) = Vrms x Arms x Power Factor 即为对一周期内其输入电压与电流乘积之积分值，需注意的是Watt≠VrmsArms而是Watt=VrmsArmsxP.F.，其中P.F.为功率因素(Power Factor)，通常无功率因素校正电路电源供应器的功率因素在0.6～0.7左右，其功率因素为1～0之间。 电源供应器的效率之定义为为输出直流功率之总和与输入功率之比值。效率提供对电源供应器正确工作的验证，若效率超过规定范围，即表示设计或零件材料上有问题，效率太低时会导致散热增加而影响其使用寿命。 6. 动态负载或暂态负载 一个定电压输出的电源，于设计中具备反馈控制回路，能够将其输出电压连续不断地维持稳定的输出电压。由于实际上反馈控制回路有一定的频宽，因此限制了电源供应器对负载电流变化时的反应。若控制回路输入与输出之相移于增益(Unity Gain)为1时，超过180度，则电源供应器之输出便会呈现不稳定、失控或振荡之现象。实际上，电源供应器工作时的负载电流也是动态变化的，而不是始终维持不变(例如硬盘、软驱、CPU或RAM动作等)，因此动态负载测试对电源供应器而言是极为重要的。可编程序电子负载可用来模拟电源供应器实际工作时最恶劣的负载情况，如负载电流迅速上升、下降之斜率、周期等，若电源供应器在恶劣负载状况下，仍能够维持稳定的输出电压不产生过高激(Overshoot)或过低(Undershoot)情形，否则会导致电源之输出电压超过负载组件(如TTL电路其输出瞬时电压应介于4.75V至5.25V之间，才不致引起TTL逻辑电路之误动作)之承受电源电压而误动作，进一步造成死机现象。 7. 启动时间与保持时间 启动时间为电源供应器从输入接上电源起到其输出电压上升到稳压范围内为止的时间，以一输出为5V的电源供应器为例，启动时间为从电源开机起到输出电压达到4.75V为止的时间。 保持时间为电源供应器从输入切断电源起到其输出电压下降到稳压范围外为止的时间，以一输出为5V的电源供应器为例，保持时间为从关机起到输出电压低于4.75V为止的时间，一般值为17ms或20ms以上，以避免电力公司供电中于少了半周或一周之状况下而受影响。 8. 其它 在电源具备一些特定保护功能的前提下，还需要进行保护功能测试，如过电压保护(OVP)测试、短路保护测试、过功保护等
上传时间： 2013-10-22
上传用户：zouxinwang
