How to meet EMC requirements as far as possible without causing too much cost pressure

There are usually several reasons for the increased cost of PCB board to meet the requirements of EMC.The first is to increase the number of strata to enhance the shielding effect.The second is to increase the ferrite bead, choke and other reasons to inhibit high frequency harmonic devices.In addition, it is usually necessary to match the shielding structure on other institutions to make the whole system meet the EMC requirements. The following are just a few of the PCB board design tips to reduce the electromagnetic radiation effects generated by the circuit. Choose devices with a slower slew rate to reduce the high-frequency component of the signal as much as possible. Ensure that the high-frequency components are not placed too close to external connectors. Pay attention to the impedance matching, routing layer and return current path of high speed signal to reduce the reflection and radiation of high frequency. Sufficient and appropriate de-coupling capacitors are placed in the power pins of each device to mitigate noise at the power layer and the formation. Pay special attention to whether the frequency response and temperature characteristics of the capacitor meet the design requirements. The ground near the external connector can be properly separated from the ground, and the ground of the connector can be connected to the chassis ground. The ground guard/shunt traces can be properly applied to some particularly high speed signals. However, pay attention to the influence of guard/shunt traces on the characteristic impedance of the line. The power supply layer is 20H smaller than the formation, and H is the distance between the power supply layer and the formation.