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标题: 关于目标阻抗的计算--瞬态电流 [打印本页]

作者: Scott.Dong 时间: 2010-10-18 16:14
标题: 关于目标阻抗的计算--瞬态电流
本帖最后由 Scott.Dong 于 2010-10-18 16:15 编辑

这是于博士《电源完整性详解》文章中的一段话。
想问大家的是，一般这个瞬态电流是怎么确定的呢？

PS：《电源完整性详解》可以看此贴https://www.eda365.com/thread-40015-1-1.html

作者: Scott.Dong 时间: 2010-10-27 16:00
好几天了，这个版块一直挺冷清，也没有哪位大侠回复下。
来分享下我看到的一份资料上的。

这个瞬态的电流变化值资料上一般是不会有的，不知道在软件仿真的时候怎么取值比较准确。目前看到的资料里就这个有提到这个问题。

作者: kj004 时间: 2010-11-15 13:24
谢谢楼主分享，最近也在学习这个pi，以前在搞SI的

作者: zmg2007 时间: 2010-11-27 11:14
看到的一个公式：

瞬态电流是实际工作时的电流，不是固定值（电路上各点都不一样吧，应该要仿真才能得到）。一般芯片应该不会工作在最大电流值上，就用最大电流的50%来计算，这样算出来的目标阻抗是有一定的指导意义的。
仅供参考

作者: Scott.Dong 时间: 2010-11-29 16:39
回复 zmg2007 的帖子

恩，最近也得到这样的一个概念。
不过，又转向DC Drop simulation了。
据说AC意义不大，还比较麻烦，各位的意见呢？

作者: calabazas 时间: 2010-12-21 08:16
几篇文章参考:

Beyond IR Drop - Dynamic Voltage Droops and Total Power Integrity.rar (324.08 KB, 下载次数: 187)

A Power Integrity Wall follows the Power Wall.rar (164.02 KB, 下载次数: 148)

Effective Current Density 2007.rar (424.57 KB, 下载次数: 146)

Effective Decoupling Radius of Decoupling Capacitor 2001-10 (slides).rar (133 KB, 下载次数: 127)

Effective Decoupling Radius of Decoupling Capacitor Chen Fang 2001.rar (196.81 KB, 下载次数: 123)

作者: calabazas 时间: 2010-12-22 18:15
回复 Scott.Dong 的帖子

提醒一下

作者: Scott.Dong 时间: 2010-12-23 22:49
回复 calabazas 的帖子

非常的感谢！！

作者: liweizhe1002 时间: 2011-5-20 17:19
感谢分享！

作者: doya 时间: 2011-5-20 17:33
动态电流的大小是很难确定的，这与sink的工作状态有很大关系。每个电源管脚的拉电流曲线也不是相同。这也就是我们常说的一条直线的目标阻抗与实际目标阻抗曲线的差别。
如果是做板级的频域仿真，这种最大电流的一半的方法可以作为一种估算方式。

作者: ugi929 时间: 2011-5-31 08:39
回复 Scott.Dong 的帖子

这段话是在哪里看到的，可否把整篇文章分享一下...

作者: bwisely 时间: 2011-8-11 19:18
先參考看看，等候面有需要在研讀

作者: jacob.ning 时间: 2011-8-13 22:21
谢谢分享，还需要研究啊。

作者: jwyu 时间: 2011-9-28 22:18
今天就在纠结这个问题，看来找到估计方法了~~

作者: willyeing 时间: 2011-9-30 11:54
经验芯片最大工作电流的1.5倍算，记牢就行，我们是工程师，用的是研究人员的结论。

作者: lzscan 时间: 2011-10-27 11:58
为什么我下不来附件呢。特定用户是什么用户？

作者: ga52Aagga52 时间: 2011-12-3 21:30
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作者: albertzzh 时间: 2012-7-23 17:26
于博士出来解释下啊~~~~

作者: tiankong2008 时间: 2012-8-30 23:21
此电流可以通过查看datasheet功率来计算。芯片的总功率可以分为两大部分基础功率和动态功率。基础功率消耗源为PLL、晶体等，动态功率一般为IO口消耗的。纵观芯片发展史，动态功率占总功率的比重越来越大，由原来的小于50%，到现在的大于50%，（低压大电流IC 如ASIC等），但很多人习惯取50%，于是会出现很多计算公式中的瞬态电流=最大电流的一半。如果为了保险瞬态电流可以取最大电流。
欢迎拍砖！

作者: killerljj 时间: 2012-10-17 11:02
看下！！！！！！！！！

作者: wan 时间: 2012-11-1 23:35
我也想知道，不过可以通过仿真得到，下面这篇文章里面有提到，可以仿真出阻抗，

https://www.eda365.com/thread-76635-1-1.html 不过只是一种方法，最好能找到里面的实例

作者: ufoosu 时间: 2012-11-7 19:27
顶，学习一下

作者: hzp_58 时间: 2013-12-24 22:45

thank you very much

作者: challex 时间: 2015-1-21 15:03

作者: laoxie10 时间: 2015-1-24 22:32
太专业了

作者: raytingg 时间: 2015-2-6 00:32
于博士的相關教材...真的是很豐富..讓人受益良多...多看一些多學一些!

作者: shark4685 时间: 2015-3-7 16:18
帖子里说的很清楚了！欢迎多来论坛讨论.

作者: Diego 时间: 2015-3-9 22:18
感谢分享！

作者: wthdyfg 时间: 2015-3-17 21:08
电源完整性详解这个贴子不存在了。

作者: granl 时间: 2016-8-6 23:28
大约是最大负载电流的一半。目标阻抗只能用来帮助分析，不能确保准确性。

作者: ARCTIC_MICHAEL 时间: 2016-8-16 11:45

thanks to share

作者: ARCTIC_MICHAEL 时间: 2016-8-16 11:46

thanks to share

作者: libing3062 时间: 2016-10-26 16:13
thanks to share

作者: cffdfg45 时间: 2016-10-27 09:34
学习一下

作者: duqiang290 时间: 2016-11-8 19:23
谢谢分享。。。

作者: guo136 时间: 2016-12-30 09:29
谢谢分享

作者: denny_9 时间: 2017-3-24 16:39
就把公式当作一个经验值，本身目标阻抗的结果也只是作为参考。工程应用，很多规格是难以定死的。

作者: Chau 时间: 2017-3-26 11:23
感谢感谢

作者: superking18 时间: 2017-4-1 08:59
好贴必须顶起来

作者: sensitiveman 时间: 2017-4-17 23:53
页面打不开了。目标阻抗的计算有个公式的吧

作者: 2209915744 时间: 2017-5-3 14:04
我不明白

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