How Active EMI Power Supply-Filter ICs Mitigate Common-Mode Emissions

A compact and efficient design of the electromagnetic interference (EMI) input filter is one of the main challenges in a high-density switching regulator, and is critical to achieving the full benefits of electrification in automotive, enterprise, aerospace and other highly constrained system environments. This technical white paper frames the theoretical background and general principles of AEF circuits in terms of sensing, injection and control techniques, with practical circuit realizations using a family of stand-alone AEF ICs from Texas Instruments for CM noise cancellation in single-phase and three-phase AC power systems. Measured results from a 3.3-kW power factor correction (PFC) AC/DC regulator will illustrate the benefits of EMI mitigation and board space savings. Click here to view the Texas Instruments' TIDM-1007 Reference Design. Click here to download the White Paper.