dcdc power supply module selection problem

When we need to have a demand for power modules, we are faced with a wide range of models, different parameters, and many brands of power modules. How to filter out the power modules that are both suitable and cost-effective is indeed a very troublesome thing!dcdc power moduleSeveral issues that need to be considered when selecting a model!

1. "Does this part of the circuit need to be isolated?" This is basically a question that every embedded system engineer will think about.

For the purpose of isolation, isolation can be divided into two categories: safety isolation and noise isolation. Due to the wide application of embedded systems, in hardware design, we often encounter complex situations such as multi-voltage power supply, digital-analog mixing, and high-speed and low-speed signals on the same board. A little careless handling will introduce interference, and at least reduce it. Product performance can interfere with communication and even cause system restart and paralysis. At this time, isolation is particularly important. In the design of embedded systems, isolated power modules are generally used to isolate power supply to different sections of the PCB, to minimize noise interference and improve system stability.

In addition, embedded systems containing industrial buses often face harsh environments such as surges, arc interference, and lightning strikes. Therefore, it is necessary to safely isolate the bus part and the embedded system part. Isolation can not only eliminate the interference of the ground loop, but also block the influence of external harsh environmental factors from entering the core system through the bus, ensuring the safety of the core system.

2. The greater the isolation voltage, the better?

Isolation voltage is an important indicator of isolated dcdc power modules. Its specifications can generally be divided into 1000VDC, 1500VDC, 2000VDC, 3000VDC, 6000VDC and other specifications. The isolation voltage here refers to the power supply within a certain period of time (usually 1 second) The higher voltage that the module can withstand and is applied between the input and output. If the isolation voltage level is higher, the protection device and design process requirements inside the power module are higher. In simpler words, the higher the cost. So how do we choose the appropriate isolation voltage when dealing with dcdc power modules?

For the selection of the isolation voltage of the power module, it needs to be selected according to the application. Generally speaking, the requirement for the isolation voltage of the power supply module is not very high for occasional use, but a higher isolation voltage can more ensure that the module power supply has a smaller leakage current, so that the module power supply has higher safety and reliability at the same time The EMC characteristics of the power module are also better, because the core devices of the embedded system have the characteristics of high integration and small package, so they are relatively fragile. Therefore, the isolation voltage level commonly used in the general application industry is 1500VDC or above. But in some special industries such as medical, outdoor communication base stations, high-voltage power, etc., the isolation requirements for power modules are even higher.

With the rapid development of technology and rapid product development has become the norm, the powerful processing capabilities of embedded systems have weakened the hardware design, and a lot of work has been handed over to the software. With a standardized hardware platform, standard interfaces, and rich drivers, it is possible to bring products to the market through rapid prototyping. Even in the increasingly compact project cycle, more and more embedded system design engineers have strongly realized that the correct and reasonable selection of dcdc power modules can not only save the trouble of power supply design and debugging, but also This improves the reliability of the overall module system and shortens the entire product development cycle.