<?xml version="1.0" encoding="gbk"?> <rss version="2.0"><channel> <title>定阅帖子更新</title> <link>http://www.broadkey.com.cn/XML.ASP</link><description>TEAM Board - 科伟奇电子</description> <copyright>TEAM 2.0.5 Release</copyright><generator>TEAM Board by TEAM5.Cn Studio</generator> <ttl>30</ttl><item><link>http://www.broadkey.com.cn/Thread.asp?tid=432 </link><title>原理图设计规范</title><author>会飞的鱼</author><pubDate>2009/12/15 11:22:38</pubDate><description><![CDATA[<div>
<div style="line-height: 20pt"><span style="font-size: 12pt">1</span><span style="font-size: 12pt">、一般规则和要求</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">1)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">按统一的要求选择图纸幅面、图框格式、电路图中的图形符号、文字符号</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">2)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">根据该产品的工作原理，将各元器件自右向左、自上而下排成一列或数列</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">3)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">安排图面时，电源部分一般安排在左下方，是、输入端在右侧，输出端在左侧</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">4)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">图中状态可变的元器件</span><span style="font-size: 12pt">(</span><span style="font-size: 12pt">如继电器</span><span style="font-size: 12pt">)</span><span style="font-size: 12pt">的工作状态，原则上的处于断开、不加电的工作位置</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">5)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">将所有芯片的电源和地引脚全部利用</span></div>
<div style="line-height: 20pt"><span style="font-size: 12pt">2</span><span style="font-size: 12pt">、信号完整性及电磁兼容考虑</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">1)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">对输入</span><span style="font-size: 12pt">/</span><span style="font-size: 12pt">输出的信号要加相应的滤波</span><span style="font-size: 12pt">/</span><span style="font-size: 12pt">吸收器件，必要时加瞬变电压吸收二极管或压敏电阻</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">2)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">在高频信号输入端串联电阻</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">3)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">高频区的去耦电容要选低</span><span style="font-size: 12pt">ESR(</span><span style="font-size: 12pt">等效串联电阻</span><span style="font-size: 12pt">)</span><span style="font-size: 12pt">的电解电容或钽电容</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">4)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">去耦电容应在满足纹波要求的条件下选择较小融值的电容，以提高其谐振频率点</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">5)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">各芯片的电源都要加去耦电容，同一芯片中各模块的电源分别加去耦电容，若为高频则要在靠近电源端加磁珠</span><span style="font-size: 12pt">/</span><span style="font-size: 12pt">电感</span></div>
<div style="line-height: 20pt"><span style="font-size: 12pt">3</span><span style="font-size: 12pt">、</span><span style="font-size: 12pt">PCB</span><span style="font-size: 12pt">完成后原理图与</span><span style="font-size: 12pt">PCB</span><span style="font-size: 12pt">的对应</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">1)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">对</span><span style="font-size: 12pt">PCB</span><span style="font-size: 12pt">分布参数敏感的元器件</span><span style="font-size: 12pt">(</span><span style="font-size: 12pt">如滤波电容、高频滤波的磁珠</span><span style="font-size: 12pt">/</span><span style="font-size: 12pt">电感等</span><span style="font-size: 12pt">)</span><span style="font-size: 12pt">的标称值进行核对、优化，若有变更应及时更新原理图和</span><span style="font-size: 12pt">BOM</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">2)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">在</span><span style="font-size: 12pt">PCB Layout</span><span style="font-size: 12pt">重排标号信息后应及时更新原理图和</span><span style="font-size: 12pt">BOM</span></div>
<div style="line-height: 20pt; text-indent: 0.2pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">3)<span style="font: 7pt 'Times New Roman'">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="font-size: 12pt">生成的</span><span style="font-size: 12pt">BOM</span><span style="font-size: 12pt">文件中，元器件明细表中不允许出现无型号的元器件。相同元器件不允许采用不同的表示方法。</span></div>
<div style="line-height: 20pt; margin: 0cm 0cm 0pt 21pt"><span style="font-size: 12pt">只有严格遵守设计规范，才能设计出清晰易懂的图纸！</span></div>
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