SaberRD Design Example: EMI Analysis of Flyback Converter

Balaji Siva Prasad Emandi

Introduction:
Switch Mode Power Supplies are being used extensively because of reduced size, weight and cost of the equipment. The consequence of this is the Electromagnetic Interference (EMI) which is an unwanted high frequency signal interfering with desired signals.
This Design example demonstrated the EMI Analysis of a Flyback Converter. The design is tested for various techniques to reduce common-mode noise. The common-mode noise from the converter is compared with the CISPR and FCC standard limits to see if the design complies with the standards. The Flyback transformer is modeled to include the capacitive coupling between windings and leakage inductances. The use of FFT calculation, available in Saber, is demonstrated to check if the design complies with the industry standards for EMI Specifications. The use of AIM scripting language is also introduced.
The details of how FFT calculation can be used measuring conducted EMI is explained in a SolvNet article. The article can be accessed at the following link.
https://solvnet.synopsys.com/retrieve/2559144.html

Circuit Snapshot:
Refer to the attached snapshot "flyback_EMI_Analysis_schematic.PNG".

How to use the Example:
Download the attached flyback_emi_analysis.zip" and unzip the contents. Open the Flyback_emi.ai_dsn in SaberRD and run the experiments listed in the Experiment Analyzer.
For more details of the design, how to run the design, etc., refer to the README.pdf file in the folder.

Note:
This design example works only in SaberRD commercial edition 2015.03 and above.