The EMI Design Suite includes a number of EMI design templates for Buck, Boost, PFC, PSFB converters, and motor drives. These EMI design templates help the user to walk through the typical conducted EMI pre-compliance iteration steps and automatically design the EMI filters with proper attenuations for both Differential Mode (DM) and Common Mode (CM) conducted emission noises, and generate a complete system that is operational and ready to simulate. For example, the buck (CISPR-22 Class B) design template is for a buck converter system that meets CISPR-22 Class B EMI standard.
The EMI Design Suite has the capability to put together an EMI pre-compliance testing system quickly with investigated circuit models and parasitic components, EMI filters, Line Impedance Stabilization Network (LISN), and DM/CM EMI noise signal analyzer. That allows engineers to evaluate and design an EMI filter in an early stage and provide guidance for circuit board and system layout. They can also study the effect of the existing layout with consideration of various CM and DM parasitic components in the system before the power converter hardware is designed. Hence, many iterations of re-layout of the board and system are avoided and the EMI pre-compliance process speed is substantially increased.
The EMI pre-compliance set-up of a boost converter system consists of an EMI filter, LISN, Signal Analyzer, CM capacitance block, and a boost power converter system. The design template for a Boost Converter (MIL-461) is shown below.
After EMI parasitic parameters, X-cap, Y-cap values, and the amplitudes of CM/DM noises of worst frequencies as well as corresponding EMI standard levels are entered, the EMI filter is automatically designed and the entire circuit is ready to be simulated and investigated for EMI performance.