How to Suppress Noise Generated by Internal Motors and Switching Power Supplies in Ventilators?

Noise suppression must be addressed at the source during the circuit design stage. For motor drive circuits, high-frequency beads or ferrite rings with excellent high-frequency characteristics should be placed as close as possible to the power pins of the power MOSFETs or driver ICs to absorb high-frequency noise. Simultaneously, low-ESR ceramic decoupling capacitors should be connected in parallel at the motor power entry point, forming an LC filter network together with the beads. For switching power supplies, key measures include selecting modules with integrated shielded inductors, using π-type filter circuits at the secondary side output, and ensuring that all high-current loop areas are minimized. In PCB layout, sensitive analog circuit areas should be adequately isolated from these noise sources, and shielding cans should be used for physical separation when necessary.