This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
標(biāo)簽: pci PCB 設(shè)計規(guī)范
上傳時間: 2013-10-15
上傳用戶:busterman
In general, a Hot Swap controller provides two importantfunctions to boards that can be plugged and unpluggedfrom a live backplane:
上傳時間: 2013-10-23
上傳用戶:行者Xin
Occasionally, we are tasked with designing circuitry for aspecific purpose. The request may have customer originsor it may be an in-house requirement. Alternately, a circuitmay be developed because its possibility is simply tooattractive to ignore1. Over time, these circuits accumulate,encompassing a wide and useful body of proven capabilities.They also represent substantial effort. These considerationsmake publication an almost obligatory propositionand, as such, a group of circuits is presented here. This isnot the first time we have displayed such wares and, giventhe encouraging reader response, it will not be the last2.Eighteen circuits are included in this latest effort, roughlyarranged in the categories given in this publication’s title.They appear at the next paragraph.
標(biāo)簽: 信號源 調(diào)節(jié)器 電源 電路分析
上傳時間: 2013-11-12
上傳用戶:012345
Switching regulators are of universal interest. LinearTechnology has made a major effort to address this topic.A catalog of circuits has been compiled so that a designengineer can swiftly determine which converter type isbest. This catalog serves as a visual index to be browsedthrough for a specific or general interest.
標(biāo)簽: Collection Switching Regulator Circuit
上傳時間: 2013-11-09
上傳用戶:mh_zhaohy
Most portable computers have built-in sockets to acceptsmall PC cards for use as extended memories, fax modems,network interfaces, wireless communicators and awide assortment of other functions. The Personal ComputerMemory Card International Association (PCMCIA)has released specifications that outline the general powerrequirements for these cards.
標(biāo)簽: PCMCIA 卡插槽 電源管理系統(tǒng)
上傳時間: 2013-11-18
上傳用戶:bcjtao
Sensing and/or controlling current flow is a fundamental requirement in many electronics systems, and the tech-niques to do so are as diverse as the applications them-selves. This Application Note compiles solutions to cur-rent sensing problems and organizes the solutions by general application type. These circuits have been culled from a variety of Linear Technology documents
標(biāo)簽: 電流檢測電路
上傳時間: 2013-10-22
上傳用戶:moshushi0009
ØCPV is the abbreviation of concentration PV. Ø It utilizes optics to concentrate the sunlight to the CPV cell to generate power. Ø The purpose of CPV is to reduce the cell’s area and the cost of PV module.
上傳時間: 2013-10-29
上傳用戶:開懷常笑
數(shù)字控制的交流調(diào)速系統(tǒng)所選用的微處理器、功率器件及產(chǎn)生PWM波的方法是影響交流調(diào)速系統(tǒng)性能好壞的直接因素。在介紹了正弦脈寬調(diào)制(SPWM)技術(shù)的基礎(chǔ)上,設(shè)計了一種以8098單片機作為控制器,以智能功率模塊IPM為開關(guān)器件的變頻調(diào)速系統(tǒng)。通過軟件編程,產(chǎn)生正弦脈沖寬度調(diào)制波形來控制絕緣柵雙極晶體管的導(dǎo)通和關(guān)斷,從而達(dá)到控制異步電動機轉(zhuǎn)速的目的。實驗結(jié)果表明,該系統(tǒng)可調(diào)頻率調(diào)電壓,穩(wěn)定度高,調(diào)速范圍寬,具有較強的實用價值 Abstract: AC variable speed with digital control systems used microprocessors, power devices and generate PWM wave is the direct factors of affecting the performance AC speed regulation system. On the basis of introducing the sinusoidal pulse width modulation (SPWM) technology,this paper designed variable speed system which used 8098 as a controller, intelligent power module IPM as switching device. Through software programming, resulting in sinusoidal pulse width modulation waveform to control the insulated gate bipolar transistor turn on and off, so as to achieve the purpose of speed control of induction motors. Experimental results show that the system can adjust frequency modulation voltage, high stability, wide speed range, has a strong practical value.
標(biāo)簽: 8098 SPWM 單片機 變頻調(diào)速系統(tǒng)
上傳時間: 2013-11-14
上傳用戶:ynwbosss
Designing Boards with Atmel AT89C51,AT89C52, AT89C1051, and AT89C2051 for Writing Flash at In-Circuit Test. Recent improvements in chips and testers have made it possible for the tester to begin taking over the role tradi-tionally assigned to the PROM program-mer. Instead of having a PROM pro- grammer write nonvolatile memories before assembling the board, the in-cir- cuit tester writes them during in-circuit testing operations. Many Teradyne Z18- series testers are now in use loading code into nonvolatile memories, micro- controllers and in-circuit programmable logic devices. The purpose of this note is to explain how the Z18 approaches the writing task for Atmel AT89C series IC’s, so that designers of boards using these chips can get the best results.
上傳時間: 2013-11-17
上傳用戶:xiaozhiqban
以C8051F020為核心處理器,設(shè)計無線傳感器網(wǎng)絡(luò)數(shù)據(jù)采集系統(tǒng)。系統(tǒng)采用SZ05-ADV型無線通訊模塊組建Zigbee無線網(wǎng)絡(luò),結(jié)合嵌入式系統(tǒng)的軟硬件技術(shù),完成終端節(jié)點的8路傳感器信號的數(shù)據(jù)采集。現(xiàn)場8路信號通過前端處理后,分別送入C8051F020的12位A/D轉(zhuǎn)換器進行轉(zhuǎn)換。經(jīng)過精確處理、存儲后的現(xiàn)場數(shù)據(jù),通過Zigbee無線網(wǎng)絡(luò)傳送到上位機,系統(tǒng)可達(dá)到汽車試驗中無線測試的目的。 Abstract: This paper designs a wireless sensor network system for data acquisition with C8051F020 as core processors.The system used SZ05-ADV wireless communication module,set up a Zigbee wireless network, combined with hardware and software technologies of embedded systems,completed the end-node 8-locale sensor signal data acquisition.Eight locale signals were sent separately into the 12-bit ADC of C8051F020 for conversion through front treatment.After accurate processing and storage,the locale data was transmitted to the host computer through Zigbee wireless.The system achieves the purpose of wireless testing in vehicle trial.
標(biāo)簽: C8051F020 Zigbee 汽車測試 系統(tǒng)設(shè)計
上傳時間: 2013-11-23
上傳用戶:dsgkjgkjg
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