How are EMI filters designed for power electronic converters?

EMI filters attenuate conducted emissions from switched-mode converters. Differential mode (DM) noise flows in power conductors; filtered with X-capacitors and DM inductors. Common mode (CM) noise flows to ground via parasitic capacitances; filtered with Y-capacitors and CM chokes. Design process: measure emissions, determine required attenuation, calculate filter cutoff frequency, select components with adequate current/voltage ratings. Damping prevents resonance. High-frequency performance limited by component parasitics. Compliance with standards (CISPR, FCC) requires proper filter design.