Customer's circuit is as bellow and they care the CMRR most.
The test input is VCM=10V@10Hz, VDIFF=100uV@10Hz.
While input from INS+ and INS-, CMRR>119dB; but from IN+ and IN-, CMRR<80dB.
Customer's requirement is how to make CMRR>110dB while input from IN+ & IN-.
Thank you and happy new year!
Marc