Analyze the characteristics of dcdc power modules

The dcdc power module is now widely used due to its small size, outstanding performance, and convenient use. Because the module power supply is easy to install and has many structural advantages, it can often be seen in the fields of mobile communication and AC equipment. The planning related to module power supply shows that the use of module power supply is very extensive. So why the dcdc power module can be widely used, so what are its characteristics and advantages, then the editor will analyze the characteristics of the dcdc power module for you!

Although the reliability of the power supply module is relatively high, it may also have shortcomings. In the dc/dc module, the shortcomings that may occur are generally as follows: 1. The output voltage of the module drops during the operation; 2. The module stops working;

3. The output voltage of the module is too high; 4. The input of the module is short-circuited; 5. The output current of the module is too large.

The modules can be strictly inspected to ensure the reliability of their use, and the power-on inspection can be carried out to remove substandard products. The shortcomings of the first two DC-DC power modules generally do not bring great danger.

The third failure method is more dangerous. It can burn the application circuit. The overvoltage protection is generally completed by the overvoltage protection circuit. Others can also be completed by adding a Zener diode at the output. When planning, choose the parameters of the diode reasonably to avoid the change of the voltage regulation point due to the different temperature i. Some modules have their own overvoltage protection. Generally speaking, modules below 25w have no overvoltage protection function, and modules above 25w are planned with overvoltage protection circuits. The overvoltage protection point is generally planned to be 135%-145% of the rated voltage. In the specific planning, it is necessary to confirm whether the module has these functions, and avoid repeated planning.

The fourth type will cause input over-current and burn out the printed circuit board in severe cases. Generally, it can be protected by selecting a suitable fuse at the input end. The fuse is generally placed near the input end of the power module when wiring. The intention of this plan is to reduce the bow|line inductance of the input line to avoid the lead inductance caused by the overvoltage of the input end when the fuse is blown.

The fifth type of dcdc power module failure can be achieved by selecting a power module with over-current protection. General power modules have over-current protection functions. This type of module can be completed by detecting the current of the primary or secondary side of the modifier. But to lose a certain efficiency. When selecting a voltage module, the larger the power rating, the better. Assuming that the derating is too large, when the user board is short-circuited, due to the existence of the transmission voltage drop, the output current is not enough to complete the module overcurrent protection, which may cause the chip to overheat or even be damaged.

Main features of dcdc power module

Small size, high reliability;

Output voltage stabilization, accuracy can reach 1%; high performance price ratio;

Multiple input and output voltages;

Built-in input filter, low electromagnetic compatibility characteristics; aluminum shell frosted oxidation, six-sided shielding.

-General occasions do not require very high isolation voltage of the module power supply, but higher isolation voltage can ensure that the module power supply has a smaller leakage current, higher safety and reliability, and better EMC characteristics, so at present The general isolation voltage level in the industry is above 1500VDC.