1. The analog ground and digital ground of a separately functioning PCB should be connected at a single point near the system ground. If the power supply voltage is the same, connect the analog and digital circuits’ power at a single point at the power inlet. If the power supply voltages differ, position a 1~2nF capacitor to provide a path for the signal return current between the two power supplies.

2. If the PCB is inserted into the motherboard, ensure the power and ground for the analog and digital circuits on the motherboard are also separated. The analog and digital grounds should be grounded at the motherboard’s ground, with the power connected at a single point near the system ground. If the power supply voltages are the same, connect the analog and digital power supplies at a single point at the power inlet. If the power supply voltages differ, place a 1~2nF capacitor near the two power supplies to provide a path for the signal return current.

3. When mixing high-speed, medium-speed, and low-speed digital circuits, allocate different layout areas for each on the printed board.

4. Separate low-level analog circuits and digital logic circuits as much as possible.

5. In multilayer PCB design, the power plane should be positioned close to the ground plane and arranged below it.

6. In multi-layer PCB design, the wiring layer should be placed adjacent to the entire metal plane.

7. Separate digital and analog circuits during multilayer PCB design, placing them on different layers if possible. If they must be on the same layer, use methods such as trenching, grounding lines, and separation. Analog and digital grounds and power supplies must remain separate and not mixed.

8. Clock circuits and high-frequency circuits, being primary sources of interference and radiation, should be arranged separately and positioned far from sensitive circuits.

9. Monitor waveform distortion during long-line transmission.

10. To minimize the loop area of interference sources and sensitive circuits, use twisted-pair and shielded wires. Twist the signal wire and ground wire (or current-carrying circuit) together to maintain the closest distance between them.