Engineers who have been doing PCB layouts for years have summarized some of the main areas of concern, of which the Power loop is a place worth considering. So, how to do the Power circuit in PCB board design?
First, the power board is more important to withstand the power loop part, in the layout should first know the power part of the circuit characteristics, in the power circuit is mainly divided into DI/DT circuit and DV/DT circuit, walk when the layout of the two lines is not the same.
Because the unit time of the DI/DT circuit is large when the current changes, this part of the circuit should be as small as possible to the loop region of the entire circuit. DV/DT circuit voltage changes in unit time will be relatively large, it is easy to cause external interference, so the circuit in the loop copper skin can not be too wide, in order to meet the bearing current, copper skin width as small as possible, different layer overlapping area as small as possible.
Two, the driving part of the line should first consider the area of the whole driving ring, as small as possible, in order to stay away from the interference source, and as close to the driving part.
Sampling signals must avoid interference with other signals as far as possible. If possible, the sampled signals can be differentially sampled and given a complete ground plane at the corresponding wiring position.