For two-layer boards, controlling EMI radiation is mainly considered from wiring and layout;

The electromagnetic compatibility issues of single-layer and double-layer boards are becoming increasingly prominent. The main reason for this phenomenon is that the signal circuit area is too large, which not only generates strong electromagnetic radiation, but also makes the circuit sensitive to external interference. The simplest way to improve the electromagnetic compatibility of the circuit is to reduce the loop area of key signals; Key signals mainly refer to signals that generate strong radiation and signals that are sensitive to external boundaries.

Single and double layer boards are typically used in low-frequency simulation designs below 10KHz:

1) Route the power supply in a radial pattern on the same layer and minimize the total length of the lines;

2) When using power and ground wires, approach each other closely; Lay a ground wire next to the critical signal line, which should be as close as possible to the signal line. This creates a smaller loop area and reduces the sensitivity of differential mode radiation to external interference.

3) If it is a double-layer circuit board, a ground wire can be laid along the signal line on the other side of the circuit board, close to the bottom of the signal line, as wide as possible.