Experience Sharing in PCB Design of Switching Power Supplies

The power circuit is an important component of an electronic product, and the design of the power circuit directly affects the performance of the product. The power circuits of our electronic products mainly include linear power supplies and high-frequency switching power supplies.

In theory, a linear power supply refers to how much current the user needs, and how much current the input terminal needs to provide; Switching power supplies provide as much power as the user needs at the input end.

Linear power supply:

Advantages of linear power supply: stable performance, no interference such as high-frequency ripple.

The drawbacks of linear power sources include heat generation and low energy utilization. There is no choice of high-power power supply.

Switching power supply:

Advantages of switching power supply:

1. Small size and light weight: Due to the absence of a power frequency transformer, the volume and weight are only 10-30% of those of a linear power supply.

2. Low power consumption and high efficiency: The power transistor operates in a switching state, so the power consumption on the transistor is low and the conversion efficiency is high, usually 60-95%, while linear power sources only have 20-40%.

Disadvantages of switching power supply:

Possible electromagnetic compatibility issues (which can be resolved through debugging) may be more expensive than current power sources (according to Moore's law, this will be resolved over time).