How to design power line interface isolation for power line carrier PLC?

The design of the power line interface isolation for a power line carrier PLC must ensure both safety and signal integrity. An isolation transformer with a 1:1 turns ratio, a primary-to-secondary withstand voltage of 3000VAC, and an insulation resistance greater than 100MΩ is used. The transformer core is made of a high-permeability material, such as PC44, and the operating frequency covers the carrier band. A common-mode inductor CML3225A-510T is deployed on the secondary side of the transformer to suppress common-mode noise. Signal transmission uses optocouplers or digital isolators, such as ADuM1410, supporting speeds up to 1Mbps. On the PCB, the isolation area has slots greater than 2mm in width to prevent creepage. The system passes withstand voltage tests (1500VAC/60s) and insulation tests (500VDC, >100MΩ). This isolation design enables the system to pass safety certifications and improves immunity by 30dB.