Hi, I have this question. An instrumentation measuring system uses a differential amplifier having a CMRR of 120 dB and differential gain of 105. The maximum differential input signal is 60 μV. If the amplified noise voltage is specified to be not more than 1% of the maximum output voltage, calculate the maximum common mode voltage that can be present in the input to the amplifier. Just need to know if this is correct or I am on the right track. I have the formula CMRR=20log10(Adiff/Acm) Then 120=20log10(10^5/Acm) Then 120/20=log10(10^5/Acm) Then 6=log10(10^5/Acm) Then taking anti logs 1000000=10^5/Acm Transpose this into Acm=10^5/1000000=0.1volt Is this correct? as when I plug the 0.1 back into the original equation I do not get the original 120dB answer. Thanks.