本文通過(guò)對(duì)微帶傳輸特性、常用板材性能參數(shù)進(jìn)行比較分析,給出用于無(wú)線通信模擬前端、高速數(shù)字信號(hào)等應(yīng)用中PCB板材選取方案,進(jìn)一步從線寬、過(guò)孔、線間串?dāng)_、屏蔽等方面總結(jié)高頻板PCB設(shè)計(jì)要點(diǎn)
上傳時(shí)間: 2013-11-10
上傳用戶:waves_0801
現(xiàn)代的電子設(shè)計(jì)和芯片制造技術(shù)正在飛速發(fā)展,電子產(chǎn)品的復(fù)雜度、時(shí)鐘和總線頻率等等都呈快速上升趨勢(shì),但系統(tǒng)的電壓卻不斷在減小,所有的這一切加上產(chǎn)品投放市場(chǎng)的時(shí)間要求給設(shè)計(jì)師帶來(lái)了前所未有的巨大壓力。要想保證產(chǎn)品的一次性成功就必須能預(yù)見(jiàn)設(shè)計(jì)中可能出現(xiàn)的各種問(wèn)題,并及時(shí)給出合理的解決方案,對(duì)于高速的數(shù)字電路來(lái)說(shuō),最令人頭大的莫過(guò)于如何確保瞬時(shí)跳變的數(shù)字信號(hào)通過(guò)較長(zhǎng)的一段傳輸線,還能完整地被接收,并保證良好的電磁兼容性,這就是目前頗受關(guān)注的信號(hào)完整性(SI)問(wèn)題。本章就是圍繞信號(hào)完整性的問(wèn)題,讓大家對(duì)高速電路有個(gè)基本的認(rèn)識(shí),并介紹一些相關(guān)的基本概念。 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...................................................................................1066.2 源同步時(shí)序系統(tǒng).......................................................................................1086.2.1 源同步系統(tǒng)的基本結(jié)構(gòu)...................................................................1096.2.2 源同步時(shí)序要求...............................................................................110第七章 IBIS 模型................................................................................................1137.1 IBIS 模型的由來(lái)...................................................................................... 1137.2 IBIS 與SPICE 的比較.............................................................................. 1137.3 IBIS 模型的構(gòu)成...................................................................................... 1157.4 建立IBIS 模型......................................................................................... 1187.4 使用IBIS 模型......................................................................................... 1197.5 IBIS 相關(guān)工具及鏈接..............................................................................120第八章 高速設(shè)計(jì)理論在實(shí)際中的運(yùn)用.............................................................1228.1 疊層設(shè)計(jì)方案...........................................................................................1228.2 過(guò)孔對(duì)信號(hào)傳輸?shù)挠绊?..........................................................................1278.3 一般布局規(guī)則...........................................................................................1298.4 接地技術(shù)...................................................................................................1308.5 PCB 走線策略............................................................................................134
標(biāo)簽: 信號(hào)完整性
上傳時(shí)間: 2014-05-15
上傳用戶:dudu1210004
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: 2014-04-18
上傳用戶:wpt
減小電磁干擾的印刷電路板設(shè)計(jì)原則 內(nèi) 容 摘要……1 1 背景…1 1.1 射頻源.1 1.2 表面貼裝芯片和通孔元器件.1 1.3 靜態(tài)引腳活動(dòng)引腳和輸入.1 1.4 基本回路……..2 1.4.1 回路和偶極子的對(duì)稱性3 1.5 差模和共模…..3 2 電路板布局…4 2.1 電源和地…….4 2.1.1 感抗……4 2.1.2 兩層板和四層板4 2.1.3 單層板和二層板設(shè)計(jì)中的微處理器地.4 2.1.4 信號(hào)返回地……5 2.1.5 模擬數(shù)字和高壓…….5 2.1.6 模擬電源引腳和模擬參考電壓.5 2.1.7 四層板中電源平面因該怎么做和不應(yīng)該怎么做…….5 2.2 兩層板中的電源分配.6 2.2.1 單點(diǎn)和多點(diǎn)分配.6 2.2.2 星型分配6 2.2.3 格柵化地.7 2.2.4 旁路和鐵氧體磁珠……9 2.2.5 使噪聲靠近磁珠……..10 2.3 電路板分區(qū)…11 2.4 信號(hào)線……...12 2.4.1 容性和感性串?dāng)_……...12 2.4.2 天線因素和長(zhǎng)度規(guī)則...12 2.4.3 串聯(lián)終端傳輸線…..13 2.4.4 輸入阻抗匹配...13 2.5 電纜和接插件……...13 2.5.1 差模和共模噪聲……...14 2.5.2 串?dāng)_模型……..14 2.5.3 返回線路數(shù)目..14 2.5.4 對(duì)板外信號(hào)I/O的建議14 2.5.5 隔離噪聲和靜電放電ESD .14 2.6 其他布局問(wèn)題……...14 2.6.1 汽車和用戶應(yīng)用帶鍵盤和顯示器的前端面板印刷電路板...15 2.6.2 易感性布局…...15 3 屏蔽..16 3.1 工作原理…...16 3.2 屏蔽接地…...16 3.3 電纜和屏蔽旁路………………..16 4 總結(jié)…………………………………………17 5 參考文獻(xiàn)………………………17
標(biāo)簽: 印刷電路板 設(shè)計(jì)原則
上傳時(shí)間: 2013-10-24
上傳用戶:18165383642
PCB LAYOUT 基本規(guī)範(fàn)項(xiàng)次 項(xiàng)目 備註1 一般PCB 過(guò)板方向定義: PCB 在SMT 生產(chǎn)方向?yàn)槎踢呥^(guò)迴焊爐(Reflow), PCB 長(zhǎng)邊為SMT 輸送帶夾持邊. PCB 在DIP 生產(chǎn)方向?yàn)镮/O Port 朝前過(guò)波焊爐(Wave Solder), PCB 與I/O 垂直的兩邊為DIP 輸送帶夾持邊.1.1 金手指過(guò)板方向定義: SMT: 金手指邊與SMT 輸送帶夾持邊垂直. DIP: 金手指邊與DIP 輸送帶夾持邊一致.2 SMD 零件文字框外緣距SMT 輸送帶夾持邊L1 需≧150 mil. SMD 及DIP 零件文字框外緣距板邊L2 需≧100 mil.3 PCB I/O port 板邊的螺絲孔(精靈孔)PAD 至PCB 板邊, 不得有SMD 或DIP 零件(如右圖黃色區(qū)).PAD
上傳時(shí)間: 2014-12-24
上傳用戶:jokey075
PCB布線對(duì)PCB的電磁兼容性影響很大,為了使PCB上的電路正常工作,應(yīng)根據(jù)本文所述的約束條件來(lái)優(yōu)化布線以及元器件/接頭和某些IC所用去耦電路的布局PCB材料的選擇通過(guò)合理選擇PCB的材料和印刷線路的布線路徑,可以做出對(duì)其它線路耦合低的傳輸線。當(dāng)傳輸線導(dǎo)體間的距離d小于同其它相鄰導(dǎo)體間的距離時(shí),就能做到更低的耦合,或者更小的串?dāng)_(見(jiàn)《電子工程專輯》2000 年第1 期"應(yīng)用指南")。設(shè)計(jì)之前,可根據(jù)下列條件選擇最經(jīng)濟(jì)的PCB形式:對(duì)EMC的要求·印制板的密集程度·組裝與生產(chǎn)的能力·CAD 系統(tǒng)能力·設(shè)計(jì)成本·PCB的數(shù)量·電磁屏蔽的成本當(dāng)采用非屏蔽外殼產(chǎn)品結(jié)構(gòu)時(shí),尤其要注意產(chǎn)品的整體成本/元器件封裝/管腳樣式、PCB形式、電磁場(chǎng)屏蔽、構(gòu)造和組裝),在許多情況下,選好合適的PCB形式可以不必在塑膠外殼里加入金屬屏蔽盒。
標(biāo)簽: pcb 電磁兼容設(shè)計(jì)
上傳時(shí)間: 2013-11-01
上傳用戶:dddddd
第二章 地線干擾與接地技術(shù)為什么要地線地環(huán)路問(wèn)題與解決方法公共阻抗耦合問(wèn)題與解決方法各種接地方法電纜屏蔽層的接地 安全地信號(hào)地地線引發(fā)干擾問(wèn)題的原因?qū)Ь€的阻抗導(dǎo)線的阻抗金屬條與導(dǎo)線的阻抗比較地線問(wèn)題-地環(huán)路隔離變壓器光隔離器共模扼流圈的作用平衡電路對(duì)地環(huán)路干擾的抑制地線問(wèn)題-公共阻抗耦合單點(diǎn)接地對(duì)噪聲的抑制接地方式種類單點(diǎn)接地串聯(lián)單點(diǎn)、并聯(lián)單點(diǎn)混合接地線路板上的地線長(zhǎng)地線的阻抗多點(diǎn)接地混合接地
上傳時(shí)間: 2013-11-30
上傳用戶:tsfh
摘要: 基于小型開(kāi)關(guān)電源會(huì)產(chǎn)生電磁干擾污染電網(wǎng),同時(shí)它們又容易受到外部電磁環(huán)境的影響,不能精確地工作。我們采用了濾波、屏蔽、接地等技術(shù),使小開(kāi)關(guān)電源的EMI被控制在EMC標(biāo)準(zhǔn)規(guī)定的極限下,使它們能夠良好地工作又不至于污染電網(wǎng)。特別在文中對(duì)小開(kāi)關(guān)電源的電路進(jìn)行了改進(jìn),使這類電源能夠有效地吸收和抑制干擾。大量的實(shí)踐證明本文中采用的方案經(jīng)濟(jì)可靠地解決了小開(kāi)關(guān)電源的抗干擾問(wèn)題,不但能夠改善小開(kāi)關(guān)電源的性能,還降低了小開(kāi)關(guān)電源的故障率,使小型開(kāi)關(guān)電源的使用范圍更加廣泛。
標(biāo)簽: 開(kāi)關(guān)電源 干擾設(shè)計(jì) 電磁
上傳時(shí)間: 2013-11-23
上傳用戶:mhp0114
一、EMC 工程師必須具備的八大技能 二、EMC 常用元件 三、EMI/EMC 設(shè)計(jì)經(jīng)典 85 問(wèn) 四、EMC 專用名詞大全 五、產(chǎn)品內(nèi)部的 EMC 設(shè)計(jì)技巧 六、電磁干擾的屏蔽方法 七、電磁兼容(EMC)設(shè)計(jì)如何融入產(chǎn)品研發(fā)流程
上傳時(shí)間: 2013-11-10
上傳用戶:wangrong
本論文系統(tǒng)研究了系統(tǒng)級(jí)封裝的電源完整性分析,電源分布網(wǎng)絡(luò)設(shè)計(jì)以及三維混合芯片堆疊引起的近場(chǎng)耦合問(wèn)題。對(duì)封裝級(jí)PDN結(jié)構(gòu)設(shè)計(jì),寬頻帶、高隔離深度的噪聲隔離抑制技術(shù)以及新型混合芯片三維堆疊屏蔽結(jié)構(gòu)進(jìn)行了重點(diǎn)研究上。
標(biāo)簽: 系統(tǒng)級(jí)封裝 電源完整性 分 電磁干擾
上傳時(shí)間: 2013-11-08
上傳用戶:gaome
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