How should the spacing between power lines and signal lines in a PCS (Power Control System) be standardized?

Maintaining proper spacing between power lines and signal lines in a PCS (Printed Circuit Board System) is a fundamental design rule for preventing coupled interference. There is no absolute standard for spacing requirements, but the following principles should be followed:

1. Voltage level determines safe spacing: First, meet safety regulations regarding clearances and creepage distances, especially on the AC side and high DC voltage sections.

2. 3W/20H rule: For high-frequency signals, it is recommended that the distance between lines be at least three times the line width (3W rule) to reduce crosstalk; if the signal line is close to the board edge, it should be recessed by at least 20 times the dielectric thickness (20H rule) to reduce edge radiation.

3. Layered isolation: The best practice is to place power lines and sensitive signal lines on different PCB layers, separated by a ground plane.

4. When unavoidable: If crossing is unavoidable, try to cross perpendicularly to reduce parallel length. For critical sensitive lines, use ground lines or guard traces to separate them from power lines.