Essential Principles of Effective Switching Power Supply PCB Layout

• Point 1: Use multiple capacitors in parallel to enhance impedance characteristics.
• Point 2: Minimize parasitic parallel capacitance of the inductor.
• Point 3: Avoid routing power or signal traces over the ground plane.
• Point 4: Minimize the area of the high-frequency loop.
• Point 5: Ensure vias placement does not disrupt high-frequency current path on the ground.
• Point 6: Different ground layers are necessary for small circuits, connected at a single point.
• Point 7: Keep the drive circuit loop between control chip and FETs as short as possible.
• Point 8: Connect components in the switching power supply and control signal circuit to the ground plane.

Grounding wire design is crucial in PCB layout to prevent interference. Here are some key considerations:

• 1. **Single-Point Grounding**: Connect different ground points to a common terminal to avoid interference.
• 2. **Thicken the Ground Wire**: Use short and wide grounding lines to maintain stable power supply operation.

When designing grounding wires, ensure the ground lines are wider than power lines and utilize unused PCB areas for grounding. Follow these principles for global wiring:

• (1) **Wiring Direction**: Align component arrangement with the schematic diagram for easy production, inspection, and maintenance.

PCB Design Best Practices

• Minimize Bending in Wiring: To ensure optimal PCB layout, it is crucial to avoid excessive bending in the wiring. Maintain a consistent line width on printed arcs and aim for corners with angles of at least 90 degrees.
• Avoid Crossed Circuits: Crossed lines on the circuit board should be avoided. Employ techniques such as “drilling” and “winding” to prevent intersections. Simplify complex circuits with bridge wires when necessary.
• Input and Output Ground: When dealing with a low-voltage DC-DC converter, ensure that the input and output circuits share a common reference ground. Connect copper ground wires on both sides of the board to establish a unified ground.

When designing a PCB, adherence to these best practices will help optimize performance and reliability.