The presentation will show you a practical step-by-step approach to EMC interference suppression for an isolated power module with a strong emphasize on unregulated narrow input range modules.
As a basis for proper EMI filter design, the principle of operation of the power electronics topology within this module, in this case self- oscillating push-pull converter, will be explained. Subsequently, the parasitics that have an effect on the EMI performance are shown and discussed. Key parasitics considered here are the transformer inter-winding capacitance, coupling capacitance between the neutral and physical earth, and the equivalent series resistance (ESR) of the input capacitor. Common mode current is generated by the rate of change of the voltage with time, dv/dt, at the switching node. A bridging capacitor from primary to secondary will be introduced and explained as a solution. The webinar will be closed with a rule of thumb to determine the value of the bridging capacitor.
We will provide a sneak preview of our upcoming power module with an integrated bridging capacitor.
