How can the common-mode inductor of the intelligent low-voltage monitoring unit be matched to low-voltage scenarios?

In low-voltage scenarios, common-mode interference is concentrated in the 10kHz-10MHz frequency range, requiring targeted matching of the common-mode inductor. For low-frequency interference (10kHz-100kHz), a CMZ3225A-701T high-value inductor (700μH) with a saturation current of 2A is selected. For mid-frequency interference (100kHz-1MHz), a CML4532A-101T (100μH) with a self-resonant frequency of 15MHz is selected. For high-frequency interference (1MHz-10MHz), a CML3225A-510T (510μH) is selected, paired with a PBZ1608E600Z0T ferrite bead. During installation, the common-mode inductor should be placed close to the interface, with a lead length less than 3mm. Through spectrum matching, the common-mode rejection ratio (CMRR) is greater than 35dB in the 10kHz-10MHz band, meeting the EN55032 Class B conducted emissions requirements.