PCB novice engineers must have encountered the problem of difficult wiring and layout. The electromagnetic interference generated by switching power supply often affects the normal operation of electronic products. Correct PCB layout of switching power supply becomes very important. A power supply that is perfectly designed on paper may not work properly on initial commissioning due to a number of issues with the power supply’s PCB layout. So is there any good way to solve it? This article summarizes the eight key points of PCB rapid wiring of switching power supply for everyone.

The electromagnetic interference generated by the switching power supply often affects the normal operation of electronic products, and the correct PCB layout of the switching power supply becomes very important. In many cases, a power supply that is perfectly designed on paper may not work properly on initial commissioning due to a number of issues with the power supply’s PCB layout.

Nowadays, the replacement speed of electronic products is extremely fast, and it is almost too fast to cover the ears. Product design engineers are more inclined to choose AC/DC adapters that are easy to purchase in the market, and install multiple sets of DC power supplies directly on the lines of the system. board. Since the electromagnetic interference generated by the switching power supply will affect the normal operation of its electronic products, the correct layout of the power supply PCB becomes very important. This article summarizes the basic points of eight-point switching power supply PCB layout based on experience.

Point 1: The capacitance of the bypass ceramic capacitor should not be too large, and its parasitic series inductance should be as small as possible. Multiple capacitors in parallel can improve the impedance characteristics of the capacitor;

Point 2: The parasitic parallel capacitance of the inductor should be as small as possible, and the farther the distance between the inductor pin pads, the better;

Point 3: Avoid placing any power or signal traces on the ground;

Point 4: The area of ​​the high-frequency loop should be reduced as much as possible;

Point 5: The placement of vias should not damage the path of high-frequency current on the formation;

Point 6: A different circuit on the system board requires different ground planes, and the ground planes of different circuits are connected to the power ground plane through a single point;

Point 7: The driving circuit loop from the control chip to the upper and lower FETs should be as short as possible;

Point 8: The power-off power circuit and the control signal circuit components need to be connected to different ground layers, and these two ground layers are generally connected through a single point phase.