What are the tips for choosing dcdc power modules

The power supply has a great influence on the stability of the system during system operation. A power supply module with poor quality stability will not only cause unstable system operation, but also cause component damage in serious cases. It is very important to choose a good power supply module. Subject.

Choose a stabledcdc power module, Its advantage is that it can reduce the time required for R&D personnel to design, so that R&D personnel can focus on their own product areas, optimize products, shorten product development and verification time, and allow products to be quickly launched on the market. Business opportunities for leading and winning.

1. Efficiency:

In the era when high-efficiency and energy-saving are advocated globally, efficiency is an important factor in model selection. It can reduce energy loss during power conversion, reduce heat treatment problems and increase module life. Therefore, in the selection of efficiency, the higher the better. .

The loss of the system during standby is also one of the issues that have been emphasized in recent years. In some applications, the system operation takes a long time in the standby state, and a power module with lower standby loss is a good choice; Nanjing Fu In the standby loss part of Laixiang Electronics' new series of products, through special treatment and design, the power loss during standby can be greatly reduced, and the overall efficiency under different load conditions can be improved, in line with the latest energy-saving requirements.

2. Operating temperature:

General temperature operation can be divided into commercial regulations (0℃~+60℃), industrial regulations (-25℃~+71℃), military regulations (-55℃~+85℃), etc. The actual conditions should be considered when selecting dcdc power modules For the operating temperature range of the system, select an appropriate temperature level.

Different temperature levels will affect the material design and selection of the power module. Choosing a suitable temperature level is a very important consideration. This will affect the stability and reliability of the dcdc power module. If the system operating temperature exceeds dcdc The use range of the power module, severe cases will cause the module to fail. If the product is operated at the limit of the temperature range, it needs to be used at a reduced load, or appropriate heat dissipation design, such as increasing the convection wind speed or increasing the heat sink, to ensure the stability of the product

3. Input voltage:

The input voltage refers to the normal operation range of the dcdc power module. Generally, the common power system is usually divided into 5V, 12V, 24V, and 48V. When the power module input voltage range is selected, depending on the input voltage range, the industry has double voltage Input and quadruple voltage input are selectable.

When selecting the input voltage, you need to pay attention to the voltage provided by the front-end power supply and whether its variation is within the operating voltage range of the dcdc power supply module. Therefore, if you choose a power supply module with double voltage input or quadruple voltage input, you can see the front-end power supply. Depending on the voltage fluctuation and stability. If the input voltage is too high or too low, it may cause abnormal operation or damage of the dcdc power module. This point must be paid special attention.

In addition, in actual applications, the voltages provided by general industrial products are mostly 12V and 24V, communication products are 24V and 48V, and the railway part uses 24V, 36V, 48V, 72V, 96V and 110V.

4. Rated power:

Generally, it is recommended that when users use it, the actual power should be rated power 7~8. Under this principle, the dcdc power module has better performance, longer life, and more effective.

If the rated power of the selected dcdc power module is much higher than the actual power used, although the performance and life are helpful, it will be more wasteful in terms of cost; if the actual power used is greater than the rated power of the dcdc power module This is of course an unreasonable design. Short-term overload operation is no problem, but long-term operation under overload conditions will affect the life of the product. In terms of Nanjing Fleishang electronic products, although most of them have 110%~180% overload protection design, it is still necessary to avoid the situation of overload operation.

5. Working frequency:

The working frequency of a dcdc power module is inversely proportional to the volume of the module, but proportional to the loss. Generally, the higher the frequency, the size of the dcdc power module can be reduced, but the conversion efficiency will be reduced; otherwise, the volume will be larger, but the conversion efficiency will increase.

The operating frequency of the power module is divided into two forms, one is fixed frequency, and the other is variable frequency.

For fixed frequency dcdc power modules, the working frequency is mostly designed in the range of 150K~500K Hz, and the frequency error is usually within +-10%ex.250KHZ+-10%.

The frequency of variable frequency dcdc power supply modules varies with different input voltages and load conditions.

Using low-power products, frequency conversion design is a good choice. The pros and cons of fixed frequency and frequency conversion depend on the actual application of the customer. Generally speaking, fixed frequency products will be easier to deal with EMI.

6. Isolation:

Generally, products with a power supply on the primary side need to have the function of isolation. In addition to improving the safety and reliability of the system, isolation can also improve the EMC characteristics and protect the secondary side.

In terms of dcdc power modules, the Isolation voltage is mostly required to be 1500V, while Nanjing Fleaxiang electronic products can reach 1600V; in addition to 1600V, standard products also have 2250V, 3000V or higher Isolation to choose from, and pass UL, TUV , CE... and other certifications are more guarantees for product selection.

7. Regulation:

Voltage stabilization refers to the stability of the output voltage. The main influencing factors are input voltage and output load. The stability of input voltage changes (LineRegulation) refers to the relative change of the output voltage when the input voltage changes; the stability of load changes (Load Regulation) refers to the stability of the output voltage when the load changes; when using unregulated products, when the input voltage or load conditions are different, the output voltage will be unstable, and the system will also be unstable, even after Damaged end parts.

8. Safety regulations: When designing products, it is necessary to consider EMI compliance with international standards, so power modules that comply with EMI regulations must be selected, and the requirements for the selection of filter components used in EMI products dcdc power modules are relatively high, and the cost will be higher. , All standard products of Fulaixiang are certified by safety regulations, which can save the time for customers to send and test, and customer products are sent for testing according to customer needs, which can be made to meet customer's various safety requirements.

9. Power supply size: As far as the appearance size of the dcdc power supply module is concerned, it is different due to the different designs of each company. When selecting the appearance size required by the user, please pay attention to the following points:

A. According to the international standard pin selection: In this way, there is no need to worry about the product being limited to one or two suppliers. The general appearance size and output pin design are compatible with major manufacturers.

B. Scalability of the same size: The product is designed to provide the same size but different power. The dcdc power supply module is used. If the system needs to be upgraded and the demand for the power supply increases, if the dcdc power supply module is selected at this time, it has the same The appearance size and pin position can be selected, so that the time and cost of the system PCBRe-layout can be saved, and the product can have more flexibility.