本人在修改一個(gè) GSM 模塊時(shí)，因?yàn)榱硗庠黾恿斯δ苣K，四層板已經(jīng)無(wú)法滿(mǎn)足設(shè)計(jì)，需要修改為六層板。因?yàn)槲疫€想共用以前的設(shè)計(jì)不想做大的修改，所以增加的兩層需要按照我的疊層增加在上面（在L2 和L3 中間增加一層，在L3 和L4 中間增加一層）。網(wǎng)上找了這方面的資料發(fā)現(xiàn)沒(méi)有。后面就作罷，四層板來(lái)推擠，實(shí)在頭大，就來(lái)摸索修改，發(fā)現(xiàn)只用三步就可搞定。留文一篇，共大家借鑒。
上傳時(shí)間： 2014-01-15
上傳用戶(hù)：CHENKAI
FPGA設(shè)計(jì)的四種常用思想與技巧
標(biāo)簽： FPGA
上傳時(shí)間： 2013-10-26
上傳用戶(hù)：debuchangshi
教你學(xué)會(huì)PROTEL四層板設(shè)計(jì)
上傳時(shí)間： 2013-10-14
上傳用戶(hù)：tfyt
PCB四層板設(shè)計(jì)講解
上傳時(shí)間： 2013-10-16
上傳用戶(hù)：遠(yuǎn)遠(yuǎn)ssad
基于FPGA的四階IIR數(shù)字濾波器
標(biāo)簽： FPGA IIR 數(shù)字濾波器
上傳時(shí)間： 2013-10-28
上傳用戶(hù)：shfanqiwei
本文探討的重點(diǎn)是PCB設(shè)計(jì)人員利用IP，并進(jìn)一步采用拓?fù)湟?guī)劃和布線工具來(lái)支持IP，快速完成整個(gè)PCB設(shè)計(jì)。從圖1可以看出，設(shè)計(jì)工程師的職責(zé)是通過(guò)布局少量必要元件、并在這些元件之間規(guī)劃關(guān)鍵互連路徑來(lái)獲取IP。一旦獲取到了IP，就可將這些IP信息提供給PCB設(shè)計(jì)人員，由他們完成剩余的設(shè)計(jì)。 圖1：設(shè)計(jì)工程師獲取IP，PCB設(shè)計(jì)人員進(jìn)一步采用拓?fù)湟?guī)劃和布線工具支持IP，快速完成整個(gè)PCB設(shè)計(jì)。現(xiàn)在無(wú)需再通過(guò)設(shè)計(jì)工程師和PCB設(shè)計(jì)人員之間的交互和反復(fù)過(guò)程來(lái)獲取正確的設(shè)計(jì)意圖，設(shè)計(jì)工程師已經(jīng)獲取這些信息，并且結(jié)果相當(dāng)精確，這對(duì)PCB設(shè)計(jì)人員來(lái)說(shuō)幫助很大。在很多設(shè)計(jì)中，設(shè)計(jì)工程師和PCB設(shè)計(jì)人員要進(jìn)行交互式布局和布線，這會(huì)消耗雙方許多寶貴的時(shí)間。從以往的經(jīng)歷來(lái)看交互操作是必要的，但很耗時(shí)間，且效率低下。設(shè)計(jì)工程師提供的最初規(guī)劃可能只是一個(gè)手工繪圖，沒(méi)有適當(dāng)比例的元件、總線寬度或引腳輸出提示。隨著PCB設(shè)計(jì)人員參與到設(shè)計(jì)中來(lái)，雖然采用拓?fù)湟?guī)劃技術(shù)的工程師可以獲取某些元件的布局和互連，不過(guò)，這個(gè)設(shè)計(jì)可能還需要布局其它元件、獲取其它IO及總線結(jié)構(gòu)和所有互連才能完成。PCB設(shè)計(jì)人員需要采用拓?fù)湟?guī)劃，并與經(jīng)過(guò)布局的和尚未布局的元件進(jìn)行交互，這樣做可以形成最佳的布局和交互規(guī)劃，從而提高PCB設(shè)計(jì)效率。隨著關(guān)鍵區(qū)域和高密區(qū)域布局完成及拓?fù)湟?guī)劃被獲取，布局可能先于最終拓?fù)湟?guī)劃完成。因此，一些拓?fù)渎窂娇赡鼙仨毰c現(xiàn)有布局一起工作。雖然它們的優(yōu)先級(jí)較低，但仍需要進(jìn)行連接。因而一部分規(guī)劃圍繞布局后的元件產(chǎn)生了。此外，這一級(jí)規(guī)劃可能需要更多細(xì)節(jié)來(lái)為其它信號(hào)提供必要的優(yōu)先級(jí)。
標(biāo)簽： PCB 分 利用IP 拓?fù)湟?guī)劃
上傳時(shí)間： 2014-01-14
上傳用戶(hù)：lz4v4
第一部分 信號(hào)完整性知識(shí)基礎(chǔ).................................................................................5第一章 高速數(shù)字電路概述.....................................................................................51.1 何為高速電路...............................................................................................51.2 高速帶來(lái)的問(wèn)題及設(shè)計(jì)流程剖析...............................................................61.3 相關(guān)的一些基本概念...................................................................................8第二章 傳輸線理論...............................................................................................122.1 分布式系統(tǒng)和集總電路.............................................................................122.2 傳輸線的RLCG 模型和電報(bào)方程...............................................................132.3 傳輸線的特征阻抗.....................................................................................142.3.1 特性阻抗的本質(zhì).................................................................................142.3.2 特征阻抗相關(guān)計(jì)算.............................................................................152.3.3 特性阻抗對(duì)信號(hào)完整性的影響.........................................................172.4 傳輸線電報(bào)方程及推導(dǎo).............................................................................182.5 趨膚效應(yīng)和集束效應(yīng).................................................................................232.6 信號(hào)的反射.................................................................................................252.6.1 反射機(jī)理和電報(bào)方程.........................................................................252.6.2 反射導(dǎo)致信號(hào)的失真問(wèn)題.................................................................302.6.2.1 過(guò)沖和下沖.....................................................................................302.6.2.2 振蕩：.............................................................................................312.6.3 反射的抑制和匹配.............................................................................342.6.3.1 串行匹配.........................................................................................352.6.3.1 并行匹配.........................................................................................362.6.3.3 差分線的匹配.................................................................................392.6.3.4 多負(fù)載的匹配.................................................................................41第三章 串?dāng)_的分析...............................................................................................423.1 串?dāng)_的基本概念.........................................................................................423.2 前向串?dāng)_和后向串?dāng)_.................................................................................433.3 后向串?dāng)_的反射.........................................................................................463.4 后向串?dāng)_的飽和.........................................................................................463.5 共模和差模電流對(duì)串?dāng)_的影響.................................................................483.6 連接器的串?dāng)_問(wèn)題.....................................................................................513.7 串?dāng)_的具體計(jì)算.........................................................................................543.8 避免串?dāng)_的措施.........................................................................................57第四章 EMI 抑制....................................................................................................604.1 EMI/EMC 的基本概念..................................................................................604.2 EMI 的產(chǎn)生..................................................................................................614.2.1 電壓瞬變.............................................................................................614.2.2 信號(hào)的回流.........................................................................................624.2.3 共模和差摸EMI ..................................................................................634.3 EMI 的控制..................................................................................................654.3.1 屏蔽.....................................................................................................654.3.1.1 電場(chǎng)屏蔽.........................................................................................654.3.1.2 磁場(chǎng)屏蔽.........................................................................................674.3.1.3 電磁場(chǎng)屏蔽.....................................................................................674.3.1.4 電磁屏蔽體和屏蔽效率.................................................................684.3.2 濾波.....................................................................................................714.3.2.1 去耦電容.........................................................................................714.3.2.3 磁性元件.........................................................................................734.3.3 接地.....................................................................................................744.4 PCB 設(shè)計(jì)中的EMI.......................................................................................754.4.1 傳輸線RLC 參數(shù)和EMI ........................................................................764.4.2 疊層設(shè)計(jì)抑制EMI ..............................................................................774.4.3 電容和接地過(guò)孔對(duì)回流的作用.........................................................784.4.4 布局和走線規(guī)則.................................................................................79第五章 電源完整性理論基礎(chǔ)...............................................................................825.1 電源噪聲的起因及危害.............................................................................825.2 電源阻抗設(shè)計(jì).............................................................................................855.3 同步開(kāi)關(guān)噪聲分析.....................................................................................875.3.1 芯片內(nèi)部開(kāi)關(guān)噪聲.............................................................................885.3.2 芯片外部開(kāi)關(guān)噪聲.............................................................................895.3.3 等效電感衡量SSN ..............................................................................905.4 旁路電容的特性和應(yīng)用.............................................................................925.4.1 電容的頻率特性.................................................................................935.4.3 電容的介質(zhì)和封裝影響.....................................................................955.4.3 電容并聯(lián)特性及反諧振.....................................................................955.4.4 如何選擇電容.....................................................................................975.4.5 電容的擺放及Layout ........................................................................99第六章 系統(tǒng)時(shí)序.................................................................................................1006.1 普通時(shí)序系統(tǒng)...........................................................................................1006.1.1 時(shí)序參數(shù)的確定...............................................................................1016.1.2 時(shí)序約束條件...................................................................................1063.2 高速設(shè)計(jì)的問(wèn)題.......................................................................................2093.3 SPECCTRAQuest SI Expert 的組件.......................................................2103.3.1 SPECCTRAQuest Model Integrity .................................................2103.3.2 SPECCTRAQuest Floorplanner/Editor .........................................2153.3.3 Constraint Manager .......................................................................2163.3.4 SigXplorer Expert Topology Development Environment .......2233.3.5 SigNoise 仿真子系統(tǒng)......................................................................2253.3.6 EMControl .........................................................................................2303.3.7 SPECCTRA Expert 自動(dòng)布線器.......................................................2303.4 高速設(shè)計(jì)的大致流程...............................................................................2303.4.1 拓?fù)浣Y(jié)構(gòu)的探索...............................................................................2313.4.2 空間解決方案的探索.......................................................................2313.4.3 使用拓?fù)淠０弪?qū)動(dòng)設(shè)計(jì)...................................................................2313.4.4 時(shí)序驅(qū)動(dòng)布局...................................................................................2323.4.5 以約束條件驅(qū)動(dòng)設(shè)計(jì).......................................................................2323.4.6 設(shè)計(jì)后分析.......................................................................................233第四章 SPECCTRAQUEST SIGNAL EXPLORER 的進(jìn)階運(yùn)用..........................................2344.1 SPECCTRAQuest Signal Explorer 的功能包括：................................2344.2 圖形化的拓?fù)浣Y(jié)構(gòu)探索...........................................................................2344.3 全面的信號(hào)完整性(Signal Integrity)分析.......................................2344.4 完全兼容 IBIS 模型...............................................................................2344.5 PCB 設(shè)計(jì)前和設(shè)計(jì)的拓?fù)浣Y(jié)構(gòu)提取.......................................................2354.6 仿真設(shè)置顧問(wèn)...........................................................................................2354.7 改變?cè)O(shè)計(jì)的管理.......................................................................................2354.8 關(guān)鍵技術(shù)特點(diǎn)...........................................................................................2364.8.1 拓?fù)浣Y(jié)構(gòu)探索...................................................................................2364.8.2 SigWave 波形顯示器........................................................................2364.8.3 集成化的在線分析(Integration and In-process Analysis) .236第五章 部分特殊的運(yùn)用...............................................................................2375.1 Script 指令的使用..................................................................................2375.2 差分信號(hào)的仿真.......................................................................................2435.3 眼圖模式的使用.......................................................................................249第四部分：HYPERLYNX 仿真工具使用指南............................................................251第一章 使用LINESIM 進(jìn)行前仿真.......................................................................2511.1 用LineSim 進(jìn)行仿真工作的基本方法...................................................2511.2 處理信號(hào)完整性原理圖的具體問(wèn)題.......................................................2591.3 在LineSim 中如何對(duì)傳輸線進(jìn)行設(shè)置...................................................2601.4 在LineSim 中模擬IC 元件.....................................................................2631.5 在LineSim 中進(jìn)行串?dāng)_仿真...................................................................268第二章 使用BOARDSIM 進(jìn)行后仿真......................................................................2732.1 用BOARDSIM 進(jìn)行后仿真工作的基本方法...................................................2732.2 BoardSim 的進(jìn)一步介紹..........................................................................2922.3 BoardSim 中的串?dāng)_仿真..........................................................................309
標(biāo)簽： PCB 內(nèi)存 仿真技術(shù)
上傳時(shí)間： 2013-11-07
上傳用戶(hù)：aa7821634
用PLC設(shè)計(jì)的四層電梯
標(biāo)簽： PLC 電梯設(shè)計(jì)
上傳時(shí)間： 2014-01-03
上傳用戶(hù)：txfyddz
四相六線步進(jìn)電機(jī)正反轉(zhuǎn)驅(qū)動(dòng)程序
標(biāo)簽： 步進(jìn) 電機(jī)正反轉(zhuǎn) 驅(qū)動(dòng)程序
上傳時(shí)間： 2013-10-31
上傳用戶(hù)：wangcehnglin
四探倒車(chē)?yán)走_(dá)實(shí)用電路及pcb圖片波形（主機(jī)部分）。
標(biāo)簽： PCB 倒車(chē)?yán)走_(dá) 主機(jī) 實(shí)用電路
上傳時(shí)間： 2013-11-10
上傳用戶(hù)：fnggknj
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