Very practical high frequency PCB circuit design 70 questions
The analog signal line cannot cross is required because the digital signal slightly faster the return current path (return current path) will try to walk along the line near the lower part of the source of flowing into the digital signal, if the analog signal line cross, returns the current generated by the noise will appear in the analog circuit in the region.
When there are multiple number / module blocks in a PCB(High Quality PCBs china) board, the usual practice is to separate numbers / modules. What are the reasons for that?
The reason for dividing the number / module is that the digital circuit generates noise in the power and the ground when switching between the high and low potential, and the magnitude of the noise is related to the speed of the signal and the magnitude of the current. If the ground plane is not split and the noise generated by the digital circuit is large, and the circuit of the analog region is very close, even if the analog signal does not cross, the analog signal will still be disturbed by ground noise. That is to say, the division of digital and analog modes can be used only when the analog circuit area is far from the circuit area which produces large noise. Key board PCB supplier china