Single board design related

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Single board design related [Copy link]

Do the signal ground and power ground of a single board have to be separated? The power is mainly the stepper motor or power MOS tube (working in switch mode). What we are doing now is to separate the signal ground and the power ground, and place a 1210 0 ohm resistor in the middle in the form of assembly variables. When looking at some foreign designs, there is no so-called signal ground or power ground, just a unified reference ground. When I do it myself, sometimes ground isolation will be a little inconvenient. Adding isolated power supply or isolation chip will increase the cost and reliability will also be affected. I am confused about this aspect now, so I would like to see if you have any good suggestions

maychang

My feeling is that it is not just the original poster, most electricians who lay out panels do not understand the impact of the current on the ground wires. Let me draw a diagram and explain it slowly.

qwqwqw2088

The ground wire in the PCB is isolated by single-point grounding. Optocouplers can be used, which does not cost much. The reliability mainly depends on the load power size. If there is interference, the high power does not need to go through the PCB line. It can be directly isolated by using the external shielded line and low-power optocoupler.

btty038

I usually separate the analog and digital and then divide them into local unit circuits