PCB News - The division of digital and analog power planes of circuit board manufacturers

The division of digital and analog power planes of circuit board manufacturers

In the analog-digital hybrid circuit, independent digital power and analog power are usually used to supply power separately. Split power planes are often used on PCBs with mixed analog and digital signals. It should be noted that the signal line close to the power layer cannot cross the gap between the power sources, and only the signal line on the signal layer close to the large area "ground" can cross the gap. The analog power supply can be designed in the form of PCB traces or fills instead of a power plane, so that the division of the power plane can be avoided.

An important step in the PCB layout process is to ensure that the power plane (and ground plane) of each component can be effectively grouped and will not overlap with other circuits, as shown in Figure 11-9. For example, in A/D circuits, the digital power reference layer and digital ground reference layer (digital ground plane) are usually located on one side of 1C, and the analog power reference layer and analog ground reference layer (analog ground plane) are on the other side. Connect the digital ground layer and the analog ground layer at a point below 1C (or at least very close to 1C) with an on resistor or a ferrite magnetic ring.

The division of digital and analog power planes of circuit board manufacturers

Shenzhen PCB manufacturers strictly follow the division rules of digital and analog power planes.

If multiple independent power supplies are used and these power supplies have their own reference layers, do not allow unrelated parts of these layers to overlap. This is because two conductor surfaces separated by a dielectric form a capacitor. When a part of the analog power layer overlaps with a part of the digital ground layer, the overlapping part of the two layers forms a small capacitor. In fact, this capacitance may be very small. In any case, any capacitor can provide a path for noise from one power supply to another, thereby rendering isolation meaningless.

The above is an introduction to the digital and analog power planes of circuit board manufacturers. Ipcb is also provided to PCB manufacturers and PCB manufacturing technology