Summary of eight key points of fast switching power supply PCB layout

Switching power supply generated by electromagnetic interference, often affect the normal work of electronic products, the correct switching power supply PCB layout has become very important. In many cases, a power supply that is perfectly designed on paper may not function properly during initial commissioning because of many problems with the PCB layout of the power supply. In this case,In this case,

Now electronic products replacement fast, is simply lightning speed, product design engineers are more inclined to choose in the market is very easy to purchase AC / DC adapter, and the number of DC power supply installed directly in the system line On the board. As the switching power supply to produce electromagnetic interference will affect the normal work of its electronic products, the right power PCB layout becomes very important. This paper summarizes the basic points of eight-point switching power PCB layout based on experience.

Here is a summary for everyone to summarize what these eight points are.

Point 1 bypass ceramic capacitor capacitor can not be too large, and its parasitic series inductance should be as small as possible, a number of parallel capacitor can improve the impedance characteristics of the capacitor;

2 inductance parasitic shunt capacitance should be as small as possible, the distance between the inductor pin pad the farther the better;

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

Point 4 High-frequency loop area should be reduced as much as possible;

Point 5 The placement of vias should not disrupt the path of high frequency currents on the formation;

Point 6 A different circuit on the system board requires a different ground plane. The ground planes of different circuits are connected to the power ground plane through a single point.

Point 7 control chip to the top and bottom FET drive circuit loop to be as short as possible;

Point 8 Power supply circuit and control signal circuit components need to connect to a different ground layer, the two strata are generally connected through a single point.