PCB anti-interference measures are as follows:

1. Reasonable circuit board wiring technology (surrounding wiring, line selection, layered processing). The wiring of power and ground wires should be as thick and short as possible to reduce loop resistance. The angle is stable, try not to appear below the 90 ° folding angle.

2. The low-frequency circuit is grounded in a single-point parallel connection, or partially connected in series and then connected in parallel. The high-frequency circuit adopts multi-point grounding.

3. Surround the crystal oscillator circuit, A / D converter and other high-frequency components as much as possible with a copper grid. The farther the signal cable is from the power cable, the better.

4. The analog input line is not parallel to the digital signal line. Important signal lines are not far away, analog input lines are not parallel to digital signal lines, and important signal lines are not parallel to digital signal lines.

5. The power and low-frequency signal connection lines use small-distance twisted pairs. When multiple signal lines are connected by a flat row, insert an isolated ground between the signal lines.

6. Minimize the electromagnetic interference between the circuit and the PCB and between the circuit boards. SMT processing electronic products pursue miniaturization, and the previously used perforated plug-in components have been unable to shrink. The functions of electronic products are more complete, and the integrated circuits (ICs) used have no perforated components, especially large-scale, highly integrated ICs, and have to use surface-mount components. The PCB power line and ground line should be as close as possible to the area surrounded by the offspring to reduce the electromagnetic interference caused by the external magnetic field cutting the power loop, and also reduce the electromagnetic radiation outside the loop.