注册 登录  
 加关注
   显示下一条  |  关闭
温馨提示!由于新浪微博认证机制调整,您的新浪微博帐号绑定已过期,请重新绑定!立即重新绑定新浪微博》  |  关闭

paul.mcdean的博客

 
 
 

日志

 
 

high speed PCB and EMC design -(2)  

2007-05-07 00:45:55|  分类: 无线通信 |  标签: |举报 |字号 订阅

  下载LOFTER 我的照片书  |

DC Power and Distribution

1. Do not allow different DC voltage planes to overlap one another. For example the 5V and 15V planes should not overlap. Bipolar DC voltage planes, such as +15V and –15V, should overlap.

2. Maximize the distributed capacitance in the DC power bus. Ideally, use parallel power and return planes with a Z0 < 1Ω.

3. Minimize the series inductance of any lumped decoupling capacitors. For boards with power and return planes, this inductance is caused by the traces and vias that connect the capacitor to the planes.

4. Provide at least one decoupling capacitor (1-100nF) for each integrated circuit DC power pin. Provide bulk decoupling (uF) where the DC power comes onto the board and at the output of each voltage regulator and DC-DC convertor.

5. For boards with power and return planes, the integrated circuits share all the decoupling capacitors on the board.

Routing of Signal Output and Return Paths

1. Current takes the path of least impedance. Above 10kHz this usually means the smallest loop area path.

2. All critical signals (DC power, high frequency, large amplitude or small amplitude) need a closely located return path. Prefer signal and return traces < 0.1 apart.

3. Treat all critical signals as current loops. Check each critical loop area before the board is built.

4. The return (ground) plane may require gaps to control the path of kHz currents. Do not use gaps to control the flow of MHz currents.

5. No trace should be permitted to cross any gaps in the return plane.

6. A small loop area is more important than short trace lengths.

7. The spacing between any trace and the board edge should not be less than the spacing to the return plane.

  评论这张
 
阅读(9)| 评论(0)
推荐 转载

历史上的今天

评论

<#--最新日志,群博日志--> <#--推荐日志--> <#--引用记录--> <#--博主推荐--> <#--随机阅读--> <#--首页推荐--> <#--历史上的今天--> <#--被推荐日志--> <#--上一篇,下一篇--> <#-- 热度 --> <#-- 网易新闻广告 --> <#--右边模块结构--> <#--评论模块结构--> <#--引用模块结构--> <#--博主发起的投票-->
 
 
 
 
 
 
 
 
 
 
 
 
 
 

页脚

网易公司版权所有 ©1997-2017