How to meet the EPSCISPR11 emission limits?

To ensure EPS meets the conducted and radiated emission limits of CISPR 11 (GB4824), systematic suppression measures are required. Conducted emission (CE) compliance relies on effective input/output EMI filters, good grounding, and optimized PCB layout. Radiated emission (RE) compliance relies more heavily on shielding and layout:

1. Source suppression: Optimize switching device drive to reduce dv/dt and di/dt; employ soft-switching technology; minimize power loop area.

2. Comprehensive shielding: Use a complete metal cabinet and ensure shielding continuity at all seams and openings (vents, cable entry points) (using gaskets, waveguide windows, shielded connectors).

3. Cable handling: All incoming and outgoing cables must be shielded, and the shielding layer should be lapped and grounded 360 degrees at the cabinet entry point. Use ferrite cores on necessary cables.

4. Filtering coordination: Effective filters reduce conducted noise, indirectly reducing radiation caused by cables. Compliance is a holistic project from chips, PCBs, modules to cabinets and cables, requiring repeated verification during the design and rectification phases.