Input/output pin issues Most power modules are pin type, so it is important to check carefully before purchasing. Generally, the input terminals of AC-DC power modules are not positive or negative because they have a rectifier bridge inside and can be used for both AC and DC. And for DC-DC power modules, it is important to distinguish the pins. If they are wired, the positive and negative poles should be distinguished, commonly in red and black. To avoid reverse connection, measures such as anti reverse diodes can be added during design.
Hot plug issue Hot plugging refers to the process of plugging and unplugging modules while they are live and loaded. At present, most power modules do not support hot plugging, and the modules that require hot plugging are redundant modules and backup modules. They can prevent module damage caused by peak voltage generated during plugging and unplugging due to the addition of control circuits.
The issue of electrical clearance and creepage distance between input and output of module baseboard In the performance parameters of the power module, there is a parameter called isolation voltage, which requires selecting a suitable withstand voltage value for practical applications. At the same time, attention should be paid to the electrical clearance parameters of the module base plate to meet the electrical isolation parameters of the product. Due to the presence of high voltage, the electrical clearance of AC-DC power modules is generally above 8mm, while DC-DC power modules generally have 3-7mm depending on the parameters.
Level issue At present, it can be roughly divided into three temperature levels: commercial, industrial, and military. When using it, attention should be paid to the application environment to avoid system paralysis caused by working temperatures exceeding the rated value. In the product technical manual, there is usually an EMC characteristic description, indicating the relative level that has been passed. At the same time, there is also a reference application circuit, and users can design the circuit according to their actual situation. It can avoid problems such as repeated modifications due to bare metal not meeting requirements or adding multiple components.
Dual power module load issue It is common to encounter phenomena such as continuous restart of auxiliary output and voltage drop when debugging dual power modules. This is due to the main road being lightly loaded or unloaded, while the auxiliary road is overloaded. Generally, the auxiliary circuit voltage relies on transformer coupling to stabilize the output, and its stability is closely related to the load. Therefore, it is required that the main circuit load is not less than 20% of the rated value.
