如何正确理解CMRR

Seven_QiQi

在有些情况下，共模输入会引起差模输出，但是当不同的共模输入，引起的是相同的差模输出，这种情况下，共模增益为0嘛？

北极微笑

字不错

chungming

in idea case, your question is yes, then the CMRR is infinity.


but in real case, as you mentioned in the figure, there has a delta R in the cirucit, so the Adm-cm will not be zero. so, the CMRR is finite.

Seven_QiQi

   

chungming 发表于 2025-8-17 00:29
in idea case, your question is yes, then the CMRR is infinity.

Thank you very much！