Grounding can be divided into four categories: floating ground, single-point grounding, multi-point grounding, and hybrid grounding.
1. Floating ground
(1) Purpose: To isolate the circuit or equipment from the common wires that may cause the circulation of the common ground wire, and the floating ground also makes it easier to cooperate with circuits of different potentials.
(2) Disadvantages: It is prone to electrostatic accumulation and strong electrostatic discharge.
(3) Compromise: access to the bleeder resistor.
2. Single point grounding
(1) Method: Only one physical point in the line is defined as the ground reference point, and all grounds that need to be grounded are connected here.
(2) Disadvantages: Not suitable for high frequency occasions.
3. Multi-point grounding
(1) Method: All points that need to be grounded are directly connected to the ground plane closest to it, so that the length of the grounding wire is the shortest.
(2) Disadvantages: Maintenance is more troublesome.
4. Hybrid grounding
Method: Select single-point and multi-point grounding as required.
The large-area copper-clad grounding in the PCB is actually multi-point grounding, so a single-sided PCB can also achieve multi-point grounding. Multi-layer PCBs are mostly high-speed circuits, and the increase of ground layers can effectively improve the electromagnetic compatibility of PCBs, which is the basic means to improve signal anti-interference.
