格雷书上有关PSSR的计算

UESTC-ADC

如题，格雷书6.3.6节中图6.18（b）计算PSSR时，用到了一个等效。

                               
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这个等效是怎么做的？一直没看懂，有没有前辈能点拨一下，不胜感激！

hsh22

你第二张图画错了
CMRR=∞时看成是共模信号，vgs=-vsg

rong00i8

两个输入端接在一起，都是-vdd，即把vdd 等效到输入端

hibai

输入输出短接！！！！！！！！！！！

lishiliang

Hi LZ:
I suppose you've made a misstake, both  (a) and (b) in the above picture are equivalent, not (b) is the equivalent of (a) as you supposed.
As Gray said, there are two sources of PSRR+, one is from VDD connected with rtail and another is from VDD connected with ro7.
According to superposition priciple, we can calculate each one respectively, and then add them up, and the sum is the total PSRR+.

That's my opinion, welcome to recorrect...