An EMI-Resistant Common-Mode Cancelation Differential Input Stage in UMC 180 nm CMOS

This letter presents an on-chip common-mode cancelation circuit (CMCC), which increases the immunity to electromagnetic interference (EMI) of the input stage in a classic CMOS operational amplifier. Two test chips, containing a classic Miller amplifier and a Miller amplifier with CMCC, respectively, have been fabricated in the UMC 180 nm CMOS process. Measurements illustrate how the latter amplifier exhibits an increased immunity to EMI compared with the former.