Operational amplifier gain-bandwidth product enhancement technique for common-mode active EMI filter compensation circuits

Abstract

In this paper, the operational amplier (op-amp) gain-bandwidth product (GBP) enhancement technique for common-mode (CM) active EMI lter compensation circuits is proposed. To evaluate the proposed concept, the CM reduction performance of active EMI lters with: voltage canceling, current canceling, and closed-loop techniques, is chosen to be veried. The design procedures of enhanced op-amp GBP of CM active EMI lters are also provided. Finally, the CM reduction performances of the proposed approach are compared and veried experimentally. From the experimental results, it can be concluded that the proposed approach can improve the CM reduction performance of conventional active EMI lters from about 5 dBuV up to 20 dBuV at a certain frequency range.