In the design of electronic circuits, more consideration is given to the actual performance of the product, and not too much consideration will be given to the product’s electromagnetic compatibility characteristics and the suppression of electromagnetic disturbances and electromagnetic immunity characteristics, in order to achieve its compatible purpose will be in the actual PCB design can be used in the following circuit measures.
(1) for each integrated circuit with a high-frequency decoupling capacitor. Each electrolytic capacitor side to add a small high-frequency bypass capacitor.
(2) Use high-capacity tantalum capacitors or polyester capacitors instead of electrolytic capacitors for charging and discharging energy storage capacitors on the board. When using tubular capacitors, the case should be grounded
(3) The signal entering the printed board should be filtered, and the signal from the high-noise area to the low-noise area should also be filtered, while using the method of series termination resistors to reduce signal reflection.
(4) MCU useless terminal should be connected to power or ground through the corresponding matching resistor. Or defined as an output, the IC should be connected to the power, ground terminal are to be connected, do not dangle
(5) The idle gate circuit inputs should not be left hanging, but connected to power or ground through the corresponding matching resistors. Idle unused op-amp positive input to ground, the negative input to the output.
(6) Try to provide some form of damping for relays, etc. (high-frequency capacitors, reverse diodes, etc.).
(7) Can be connected in series with a resistor on the PCB alignment to reduce the rate of jumping along the upper and lower control signal lines.