How should the strong and weak current circuits of the PAC (Power Amplifier) motherboard be isolated and laid out?

The isolation layout of strong and weak current circuits on the PAC motherboard of the intelligent controller is the foundation for preventing noise coupling. Strong current areas (such as switching power supplies and relay drivers) should be located near the power interface at the edge of the board, while weak current areas (such as the CPU and ADC) should be placed in the center of the board or away from the strong current areas, with a minimum distance of 20mm between them. An isolation strip with a width of no less than 5mm should be installed between the strong and weak current circuits, without any traces or copper foil. If necessary, slots (1mm wide) should be cut and filled with insulating material.

Power lines entering from the edge of the board should be filtered before entering the weak current area. Filtering devices (such as CMZ7060A-701T) should be placed at the edge of the isolation strip. When signal lines cross the isolation strip, isolation devices (such as optocouplers and isolation transformers) or common-mode inductors (such as CMZ2012A-900T) should be used. After the layout, the coupling capacitance between strong and weak current circuits should be less than 1pF. Tests show that the isolation layout can reduce noise in the weak current area by 30dB and improve ADC sampling accuracy by 2 bits, meeting the IEC61000-4-8 power frequency magnetic field immunity test requirements.