基于高速FPGA 的PCB 設(shè)計(jì)技巧 如果高速PCB 設(shè)計(jì)能夠像連接原理圖節(jié)點(diǎn)那樣簡(jiǎn)單,以及像在計(jì)算機(jī)顯示器上所看到的那樣優(yōu)美的話,那將是一件多么美好的事情。然而,除非設(shè)計(jì)師初入PCB 設(shè)計(jì),或者是極度的幸運(yùn),實(shí)際的PCB 設(shè)計(jì)通常不像他們所從事的電路設(shè)計(jì)那樣輕松。在設(shè)計(jì)最終能夠正常工作、有人對(duì)性能作出肯定之前,PCB設(shè)計(jì)師都面臨著許多新的挑戰(zhàn)。這正是目前高速PCB設(shè)計(jì)的現(xiàn)狀–設(shè)計(jì)規(guī)則和設(shè)計(jì)指南不斷發(fā)展,如果幸運(yùn)的話,它們會(huì)形成一個(gè)成功的解決方案。
標(biāo)簽: FPGA PCB 設(shè)計(jì)技巧
上傳時(shí)間: 2013-11-02
上傳用戶:cainaifa
高速PCB設(shè)計(jì)指南(21IC pcb區(qū)精華)
上傳時(shí)間: 2014-01-13
上傳用戶:bs2005
在當(dāng)今的工業(yè)領(lǐng)域,系統(tǒng)電路板布局已成為設(shè)計(jì)本身的一個(gè)組成部分。因此,設(shè)計(jì)工程師必須了解影響高速信號(hào)鏈設(shè)計(jì)性能的機(jī)制。在高速模擬信號(hào)鏈設(shè)計(jì)中,印刷電路板(PCB)布局布線需要考慮許多選項(xiàng),有些選項(xiàng)比其它選項(xiàng)更重要,有些選項(xiàng)則取決于應(yīng)用。最終的答案各不相同,但在所有情況下,設(shè)計(jì)工程師都應(yīng)盡量消除最佳做法的誤差,而不要過(guò)分計(jì)較布局布線的每一個(gè)細(xì)節(jié)。本應(yīng)用筆記提供的信息對(duì)設(shè)計(jì)工程師的下一個(gè)高速設(shè)計(jì)項(xiàng)目會(huì)有所幫助。
上傳時(shí)間: 2014-05-15
上傳用戶:wd450412225
EDA技術(shù)已經(jīng)研發(fā)出一整套高速PCB和電路板級(jí)系統(tǒng)的設(shè)計(jì)分析工具和方法學(xué),這些技術(shù)涵蓋高速電路設(shè)計(jì)分析的方方面面:靜態(tài)時(shí)序分析、信號(hào)完整性分析、EMI/EMC設(shè)計(jì)、地彈反射分析、功率分析以及高速布線器。
標(biāo)簽: PCB 經(jīng)驗(yàn)
上傳時(shí)間: 2013-10-15
上傳用戶:frank1234
理論研究和實(shí)踐都表明,對(duì)高速電子系統(tǒng)而言,成功的PCB設(shè)計(jì)是解決系統(tǒng)EMC問(wèn)題的重要措施之一.為了滿足EMC標(biāo)準(zhǔn)的要求,高速PCB設(shè)計(jì)正面臨新的挑戰(zhàn),在高速PCB設(shè)計(jì)中,設(shè)計(jì)者需要糾正或放棄一些傳統(tǒng)PCB設(shè)計(jì)思想與做法,從應(yīng)用的角度出發(fā),結(jié)合近年來(lái)高速PCB設(shè)計(jì)技術(shù)的一些研究成果,探討了目前高速PCB設(shè)計(jì)中的若干誤區(qū)與對(duì)策.
標(biāo)簽: PCB
上傳時(shí)間: 2013-10-19
上傳用戶:nairui21
對(duì)高速PCB中的微帶線在多種不同情況下進(jìn)行了有損傳輸?shù)拇當(dāng)_仿真和分析, 通過(guò)有、無(wú)端接時(shí)改變線間距、線長(zhǎng)和線寬等參數(shù)的仿真波形中近端串?dāng)_和遠(yuǎn)端串?dāng)_波形的直觀變化和對(duì)比, 研究了高速PCB設(shè)計(jì)中串?dāng)_的產(chǎn)生和有效抑制, 相關(guān)結(jié)論對(duì)在高速PCB中合理利用微帶線進(jìn)行信號(hào)傳輸提供了一定的依據(jù).
標(biāo)簽: PCB 微帶線 串?dāng)_分析
上傳時(shí)間: 2013-10-26
上傳用戶:dragonhaixm
在高速數(shù)字電路飛速發(fā)展的今天,信號(hào)的頻率不斷提高, 信號(hào)完整性設(shè)計(jì)在P C B設(shè)計(jì)中顯得日益重要。其中由于傳輸線效應(yīng)所引起的信號(hào)反射問(wèn)題是信號(hào)完整性的一個(gè)重要方面。本文研究分析了高速PCB 設(shè)計(jì)中的反射問(wèn)題的產(chǎn)生原因,并利用HyperLynx 軟件進(jìn)行了仿真,最后提出了相應(yīng)的解決方法。
上傳時(shí)間: 2013-10-16
上傳用戶:2728460838
隨著系統(tǒng)設(shè)計(jì)復(fù)雜性和集成度的大規(guī)模提高,電子系統(tǒng)設(shè)計(jì)師們正在從事100MHZ以上的電路設(shè)計(jì),總線的工作頻率也已經(jīng)達(dá)到或者超過(guò)50MHZ,有一大部分甚至超過(guò)100MHZ。目前約80% 的設(shè)計(jì)的時(shí)鐘頻率超過(guò)50MHz,將近50% 以上的設(shè)計(jì)主頻超過(guò)120MHz,有20%甚至超過(guò)500M。當(dāng)系統(tǒng)工作在50MHz時(shí),將產(chǎn)生傳輸線效應(yīng)和信號(hào)的完整性問(wèn)題;而當(dāng)系統(tǒng)時(shí)鐘達(dá)到120MHz時(shí),除非使用高速電路設(shè)計(jì)知識(shí),否則基于傳統(tǒng)方法設(shè)計(jì)的PCB將無(wú)法工作。因此,高速電路信號(hào)質(zhì)量仿真已經(jīng)成為電子系統(tǒng)設(shè)計(jì)師必須采取的設(shè)計(jì)手段。只有通過(guò)高速電路仿真和先進(jìn)的物理設(shè)計(jì)軟件,才能實(shí)現(xiàn)設(shè)計(jì)過(guò)程的可控性。傳輸線效應(yīng)基于上述定義的傳輸線模型,歸納起來(lái),傳輸線會(huì)對(duì)整個(gè)電路設(shè)計(jì)帶來(lái)以下效應(yīng)。 · 反射信號(hào)Reflected signals · 延時(shí)和時(shí)序錯(cuò)誤Delay & Timing errors · 過(guò)沖(上沖/下沖)Overshoot/Undershoot · 串?dāng)_Induced Noise (or crosstalk) · 電磁輻射EMI radiation
標(biāo)簽: 高速電路 傳輸線 效應(yīng)分析
上傳時(shí)間: 2013-11-16
上傳用戶:lx9076
LVDS(低壓差分信號(hào))標(biāo)準(zhǔn)ANSI/TIA /E IA26442A22001廣泛應(yīng)用于許多接口器件和一些ASIC及FPGA中。文中探討了LVDS的特點(diǎn)及其PCB (印制電路板)設(shè)計(jì),糾正了某些錯(cuò)誤認(rèn)識(shí)。應(yīng)用傳輸線理論分析了單線阻抗、雙線阻抗及LVDS差分阻抗計(jì)算方法,給出了計(jì)算單線阻抗和差分阻抗的公式,通過(guò)實(shí)際計(jì)算說(shuō)明了差分阻抗與單線阻抗的區(qū)別,并給出了PCB布線時(shí)的幾點(diǎn)建議。關(guān)鍵詞: LVDS, 阻抗分析, 阻抗計(jì)算, PCB設(shè)計(jì) LVDS (低壓差分信號(hào))是高速、低電壓、低功率、低噪聲通用I/O接口標(biāo)準(zhǔn),其低壓擺幅和差分電流輸出模式使EM I (電磁干擾)大大降低。由于信號(hào)輸出邊緣變化很快,其信號(hào)通路表現(xiàn)為傳輸線特性。因此,在用含有LVDS接口的Xilinx或Altera等公司的FP2GA及其它器件進(jìn)行PCB (印制電路板)設(shè)計(jì)時(shí),超高速PCB設(shè)計(jì)和差分信號(hào)理論就顯得特別重要。
上傳時(shí)間: 2013-11-19
上傳用戶:水中浮云
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
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