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標題:
在鎖相迴路中如何決定迴路頻寬K呢?
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作者:
option318
時間:
2007-8-17 11:35 AM
標題:
在鎖相迴路中如何決定迴路頻寬K呢?
如題,請問先進們,在鎖相迴路中要如何決定迴路頻寬K呢?它又和Phase margin、Gain margin有關嗎? :f17
作者:
kmchen3089
時間:
2007-8-20 07:14 PM
標題:
回復 #1 option318 的帖子
回復 #1 option318 的帖子
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(1) 首先 open loop gain(迴路頻寬K )must <= pfd之比較頻率之十分之一
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否則(指>pfd之比較頻率之十分之一)要用Z domain 去分析charge pump
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pll ,且亦有unstability issue
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(see Charge-pump phase lock loops paper by Gardner
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IEEE Trans.Comm,vol Com-28,pp1849-1858,November 1980)
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(2) loop BW is related to jitter (or phase noise) ,and locking time
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so you have to consider loop BW from jitter & locking time spec
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(3)phase margin is decided by relation ship among zero freq ,loop unity gain freq , pole freq
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(4) In my opinion ,gain margin is not considered in pll design
作者:
jasonxilion
時間:
2007-11-16 09:38 PM
gain margin is not considered in pll design?
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i don't think so.
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isn't it dealt with the stability?
作者:
賴永諭
時間:
2008-2-1 07:22 PM
書上都有講哩...加油看看先....
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應該不難找到哩...
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