What are the precautions in the power supply design process?

Date：2022-08-30 16:23:37Views：680

With the increasingly extensive and diversified applications in the industry, the power supply products also continue to develop in the direction of high frequency, high efficiency, high density, low voltage, large current and diversification. With the rapid development trend, the PCB design of power products is facing greater challenges, mainly including power conversion efficiency, thermal analysis, power plane integrity and EMI (electromagnetic interference). At the same time, the packaging structure and external dimensions of power products are increasingly standardized to meet the requirements of the global integrated market.

First, power conversion efficiency. Conversion efficiency refers to the ratio of the output power of the power supply to the input power actually consumed. In practical applications, electric energy cannot be completely converted, and there will be certain energy consumption in the middle. Therefore, no matter what kind of circuit, there must be efficiency problems in power conversion. For linear power supply, heat dissipation of LDO shall be considered; For switching power supply, the loss of switch tube should be considered.

Secondly, energy loss will inevitably generate heat, which involves heat dissipation. In addition, as the load becomes heavier, the power consumption of the power supply chip increases. Therefore, the thermal distribution is a problem that must be considered in the power supply design.

The third is the power plane integrity design. To maintain the integrity of the power supply is to maintain the stable power supply of the power supply. In actual systems, there are always noises of different frequencies. For example, the natural frequency of PWM or the variable frequency control signal of PFM, the fast di / dt will produce the signal of current fluctuation, so a low impedance power supply plane design is necessary.

Finally, there is EMI (electromagnetic interference). Switching noise will be generated when the switching power supply is continuously switched on and off. If the loop inductance is not considered in the design process, the excessive return path will cause EMI problems.

The above is the relevant contents of the power supply design considerations of the Chuangxin testing small compilation. I hope it will be helpful to you. Experience shows that in the design process, if possible risks can be predicted and avoided in advance, the success rate will be greatly improved.