Unreasonable ground wire design will cause interference on the printed circuit board, fail to reach the design target, or even fail to work. The ground wire is the reference point of the potential in the circuit, and it is also the current common channel. The ground potential is theoretically zero potential, but in fact, due to the impedance of the wire, the potential is not zero everywhere. As long as the ground wire has a certain length, it is not an equipotential point that is zero everywhere. The ground wire is not only an indispensable common channel of the circuit, but also a channel of interference.

One point grounding is the basic principle of eliminating ground wire interference. The ground wires of all circuits and equipment must be connected to a unified ground point, and this point is used as the zero potential reference point (surface) of the circuit and equipment. One-point grounding is divided into a common grounding line in series with one-point grounding and an independent grounding line in parallel with one-point grounding.

One-point grounding with a common ground wire is relatively simple. The ground lead of each circuit is relatively short and its resistance is relatively small. This grounding method is often used for grounding in equipment cabinets. The independent ground wire is connected in parallel with one point to ground. Only one physical point is defined as the ground reference point. The other points that need to be grounded are directly connected to this point. The ground potential of each circuit is only related to the impedance of the ground current base of this circuit. The impact of other circuits.