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Industrial control power supply manufacturers will take you to a comprehensive understanding of power modules from 5 aspects!

Edit:Nanjing Fulaixiang Electronics Co., Ltd.UpDate:2018-06-29

The power module is a power supply that can be directly mounted on a printed circuit board. Its characteristics are that it can be an application-specific integrated circuit (ASIC), digital signal processor (DSP), microprocessor, memory, field programmable gate array (FPGA) ) And other digital or analog loads to provide power. Generally speaking, this type of module is called a point-of-load (POL) power supply system or a point-of-use power supply system (PUPS). Due to the many advantages of the modular structure, the modular power supply is widely used in switching equipment, access equipment, mobile communications, microwave communications, optical transmission, routers and other communications fields, as well as automotive electronics, aerospace, and so on.Industrial control power supplyfactoryTake you to fully understand the power module from 5 aspects!


1. The role of the power supply module


Isolation, protection (short-circuit protection, over-voltage protection, under-voltage protection, over-current protection, other protection,) voltage exchange, voltage stabilization, noise reduction and other functions. Although the load current of each power module suddenly decreases, the output power of the system will not be affected in any way.


When the power module is plugged in with power, the converter temporarily maintains the off state before all the input and output terminals are connected. Otherwise, during hot plugging, irregular on-off of the contact points of the connector may damage the converter module, or even damage the entire system in severe cases.

  

2. The use characteristics of the power supply module


The ac/dc converter with integrated chip control has excellent anti-interference characteristics and electromagnetic compatibility. The pins use 5PIN, 24PIN and other dual in-line plugs, and are packaged in metal copper and high flame-retardant plastic shell without any external components. To work.


The power module is suitable for various analog circuits, A/D conversion, various amplifiers and high-precision measuring instruments and equipment. Its shell is made of aluminum alloy radiator. The performance of the power supply module.

  

3. The composition of the power module virtual test system


With the development of virtual instrument technology and computer testing technology, it is possible to introduce computer virtual testing technology in the traditional power supply testing field. We designed a new type of power supply test instrument according to market demand. It uses virtual measurement methods based on digital adjustment and computer analysis instead of the original analog measurement method, and achieves accurate and rapid measurement of various performance indicators of power products. , And can make various data statistics and analysis.

  

4. Potting of ac-dc power module


The potting of the ac-dc power module is very important. This process not only involves the protection of the ac-dc power module (waterproof, moisture-proof, dust-proof, anti-corrosion, etc.), but also involves the heat of the ac-dc power module. design.

  

5. Power supply module selection guide


Several aspects that need to be considered when selecting a power supply module: rated power, package type, temperature range and derating use, isolation voltage, power consumption and efficiency


1. Rated power


Generally, it is recommended that the actual power used is 30-80% of the rated power of the module power supply (the specific ratio is also related to other factors, which will be mentioned later.). All aspects of the module power supply performance within this power range are fully and stable. reliable. All module power supplies have a certain overload capacity, but it is still not recommended to work under overload conditions for a long time, after all, this is a short-term emergency measure.


The second is to choose according to the temperature range. If a product with a smaller temperature range is selected due to cost considerations, but sometimes the temperature is approaching the limit, what should be done? Use derating. That is to choose a product with a larger power or package, so that the temperature rise of the "big horse-drawn car" will be lower, which can alleviate this contradiction to a certain extent. A compromise should be considered.

Commercial grade (0 ℃ to +70 ℃)

Industrial grade (-40 ℃ to +85 ℃)

Military grade (-55 ℃ to +125 ℃)

  

2. Package form

  

There are various packaging forms of module power supplies, including those that comply with international standards and non-standard ones. For the same company's products, the same power product has different packages, and the same package has different power. Then how to choose the package form? There are three main ones. Aspects: ① The volume should be as small as possible under certain power conditions, so as to give other parts of the system more space and more functions; ② Try to choose products that conform to international standard packaging, because the compatibility is better, not limited to one or two suppliers ; ③ It should be extensible to facilitate system expansion and upgrade. All comply with international standards, are half-brick and full-brick packages widely used in the industry, and are fully compatible with famous brands such as VICOR and LAMBDA. The power range of half-brick products covers 50-200W, and full-brick products cover 100-300W.


3. Temperature range and derating use


Generally, the module power supplies of manufacturers have several temperature range products to choose from: commercial grade, industrial grade, military grade, etc. When choosing a module power supply, the actual operating temperature range must be considered, because the temperature grade is different, the material and manufacturing process are different. Prices vary greatly, and improper selection will also affect the use, so we have to carefully consider. There are two options: one is to choose according to the use power and packaging form. If the actual use power is close to the rated power under a certain volume (package form), then the nominal temperature range of the module must strictly meet the actual needs or even Slight margin.


dc/dc means direct current to (to) direct current (conversion of different direct current power values), as long as it meets this definition, it can be called a dcdc converter. Specifically, it refers to converting the input DC power into AC power through a self-excited oscillation circuit, and then converting the voltage through a transformer to DC power output, or converting AC power to high-voltage DC power output through a voltage doubler rectifier circuit.


The dc/dc module power supply is widely used in communication, network, industrial control, railway, military and other fields because of its small size, outstanding performance, and convenient use. How to choose the dc/dc module power supply correctly and reasonably? From the perspective of the development and design of the dc/dc module power supply, I will talk about this issue for the reference of the majority of system designers.


4. Frequency conversion and fixed frequency


Like all switching devices, dc/dc converters will produce noise during operation, so the filter performance is also an important basis for selection. The integrated dc/dc converter usually uses variable frequency switching technology or fixed frequency switching technology. The fixed-frequency switching converter is much simpler in this respect, and even an LC filter can be used.


5. Working frequency


Generally speaking, the higher the operating frequency, the smaller the output ripple noise, and the better the dynamic response of the power supply. However, the higher the requirements for the components, especially the magnetic materials, the higher the cost, so the domestic module battery talent power supply product switch The frequency is mostly below 300kHz, even some only about 100kHz, so it is difficult to meet the requirements of dynamic response under load changes, so high-demand applications should consider using products with high switching frequency. On the other hand, when the switching frequency of the module power supply is close to the signal operating frequency, it is easy to cause beat oscillation, and this should be taken into consideration when selecting.


6. Isolation


Most of the circuits must be isolated, that is, the load and the noise of the load to the local power supply are separated from the other loads and noise of the power grid. Only isolated converters can meet this requirement. In addition to the above requirements, the use of isolated converters can also achieve differential output and bipolar output. In addition, connect the output high voltage end of the isolated converter to the power ground of the load to form a negative power supply. Since the voltage reference point is not ground, the load can obtain a higher voltage. The high voltage applied between the input terminal and the output terminal that the converter can withstand within a certain time limit (usually 1 second) is called the isolation strength of the converter. Therefore, when designing a low-noise power supply, a dc/dc converter with high isolation strength and low isolation capacitance should be selected to reduce leakage current.


Generally, a high isolation voltage is required in medical equipment. In this case, the leakage current is small and the harm to the body is small. In general occasions, the isolation voltage requirements of the module power supply are not very high, but higher isolation voltage can ensure that the module power supply has smaller leakage current, higher safety and reliability, and better EMC characteristics. Therefore, the current industry The general isolation voltage level is above 1500VDC.


7. Power consumption and efficiency


According to the formula, Pin, Pout, and P consumption are respectively the module power input, output power and its own power loss. It can be seen that under certain conditions of output power, the smaller the module loss P, the higher the efficiency, the lower the temperature rise, and the longer the service life. Of course, the smaller the loss, the more it meets the requirements of energy saving.

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The above is the power module summarized by the industrial control power supply manufacturer, I hope it will be helpful to you!


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