Starting EMI Evaluation and Design at an early stage of product development to ensure the success of EMI compliance

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.

Structured EMI Design Process

Speed up EMI pre-compliance

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 single-phase Boost Converter (MIL-461) is shown below.



EMI Templates 2021b
Other design templates provided are:


  • General design template
  • Buck Converter (CISPR-22 Class-B)
  • PFC (FCC Class-B)
  • Phase-shift full-bridge DC-DC (CISPR-25 Level-4)
  • PMSM Drive (CISPR-25 Level-3)
  • Vienna Rectifier (CISPR-22 Class-B)


The newest addition to the templates (added in PSIM 2021b) and the first 3-phase power converter system template using a Vienna rectifier is shown below. This template utilizes 3-phase elements (EMI Filter, LISN, Signal Analyzer) and supports L-type, pi-type, and T-type filters.

Explore the EMI Design Suite

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.

Aside from the L-type filter, with the latest version PSIM 2021b, we are now offering pi-type and T-type filters for higher attenuation of up to 60 dB.

These EMI filters also include ESR and ESL to Capacitor Cx and Cy, and inter-winding capacitance to common-mode choke.

EMI Filter Types 2021b

EMI Design Suite Overview


Quickly put together a power converter system

incl. parasitic inductances/ capacitances and EMI filters with detailed electronic circuit models

Reduce the time for EMI filter design, debugging, and certification significantly

Qualitative and step-by-step guidance in EMI analysis and filter design

Study different “what if” scenarios and the effect of switching transient

Guidance for board and system layout

Study the effect of the existing layout

with consideration of various common-mode and parasitic components

Common platform for system/HW/testing engineers

to communicate and work through the EMI design/testing related issues