(FPGA) and other digital or analog loads. So what should I pay attention to when choosing a power module?
I. Rated Power Theoretically speaking, when selecting modules, the greater the power, the better, so that the system can run under higher requirements. But the greater the power, the larger the volume and the higher the cost. Therefore, when designing the power supply module, it is best to choose products with working power of 30-80% of the used power supply module, because for general modules, the performance of module power supply is relatively stable and reliable within this power range, which is more conducive to the long-term operation of the module. Choosing too large a power supply product will cause waste; If the power is just right or too small, it will easily lead to overload, light systems will be unstable, and heavy components will be burned. Although some power module products can be overloaded at present, they can only be used in an emergency, and long-term use is not recommended. Of course, this depends on different products and different requirements. You can choose the most suitable power module according to your product characteristics and needs.
Second, there are many kinds of packaging forms for power modules. Some commonly used products meet international standards, and there are many non-standard products. Moreover, the products of the same company will have different packaging forms for the same power; On the contrary, the same package will have different power, which can be reasonably selected according to the requirements of its own products. Generally, three points are considered: 1. On the premise of determining the power, the package size should be as small as possible to meet the heat dissipation requirements of the product, which is more conducive to the volume control of the product and can also leave room for more important components. Of course, if the size is not very important, in order to make the product more weighty, you can also choose a larger size to get better heat dissipation effect. 2. Try to choose products that are in line with international standards. Because these products are mature products that have been widely used and verified, the risk of product development is reduced. And later, for some reason, it was easier to change the same standard products of other brands. 3. It is best to have expansibility, which is convenient for later expansion and upgrade. For example, the same package, due to the later product upgrade, can be replaced with more power but the size and package remain unchanged, so that the product upgrade can be completed quickly. Therefore, it can be seen that the packaging form is also considered according to your own needs. Especially for some products with their own characteristics, manufacturers can be required to develop independently to meet the requirements of their own products, which can prevent others from copying products and protect their own products to a certain extent. And then constantly improve in use to make power products better and better.
Third, the temperature range and working environment At present, the classification of power modules is mainly commercial, industrial and military, and different levels have requirements for the environment, such as working temperature, vibration, humidity and dust. Therefore, when selecting modular products, we should fully consider the environment in which the products are located. If the choice is improper, it will affect the use. Users should take this requirement seriously, and if they have special requirements, they should explicitly ask the technical engineer to avoid affecting the work progress. There are two options: one is based on the power used and the packaging form. If the actual power used is close to the rated power in a certain volume (package form), then the nominal temperature range of the module must strictly meet the actual needs and even have a slight margin. The second is to choose according to the temperature range. What should I do if I choose a product with a smaller temperature range for cost reasons, but sometimes the temperature is close to the limit? Not in favor of use. That is to say, choose products or packaging with higher power to make the temperature rise of "big horse-drawn car" lower, which can alleviate this contradiction to some extent. The derating ratio varies with different power levels, generally above 50W.
3~ 10W/℃ or choose the products with general temperature range, which has lower price, larger power margin and better packaging form. Consideration should be compromised.
For other special requirements, you can contact the engineer to confirm the use environment of the product.
Iv. operating frequency generally speaking, the higher the operating frequency, the smaller the output ripple noise and the better the dynamic response of the power supply. But the requirements for components, especially magnetic materials, are also higher. The switching frequency of module power supply is generally below 300kHz or even lower. Therefore, it is necessary to choose products with higher switching frequency in high demand occasions.
Verb (abbreviation of verb) isolation voltage Generally speaking, the isolation voltage of module power supply is not very high, but higher isolation voltage can ensure that module power supply has smaller leakage current, higher safety and reliability and better EMC characteristics. Therefore, at present, the isolation voltage level in the industry is above 65,438+500 VDC.
6. The fault protection function means that when the external circuit of the module power supply fails, the module power supply can automatically enter the protection state without permanent failure, and should automatically return to normal after the external fault disappears. The protection function of module power supply should at least include input overvoltage, undervoltage and soft start protection; Output overvoltage, overcurrent and short circuit protection, and high-power products should also have over-temperature protection.
Wide input voltage 2: 1 (highest: lowest) conversion efficiency 84% Wide working temperature range: -40~85℃ Flame retardant meets the requirements of UL94-V0 (plastic shell only).
Input and output isolation voltage:1500 VDC; Output short circuit and overcurrent protection (automatic recovery); Output voltage accuracy of copper case (E7)/ plastic case (E2): main circuit 1%, auxiliary circuit 3%.
Ripple and noise (20MHz, nominal input voltage):: Vo≤5.0V, ≤ 50mvp-p; Vo≥48V，≤ 180 MVP-p； Others: ≤1100mvp-p
The product is guaranteed for 5 years and can produce any voltage between 3.3 and 48 VDC.
Seven. Power consumption and efficiency When the output power is constant, the smaller the module loss P consumption, the higher the efficiency, the lower the temperature rise and the longer the service life. In addition to the normal loss at full load, there are two losses worthy of attention: no-load loss and short-circuit loss (module power loss at output short-circuit), because the smaller these two losses, the higher the efficiency of the module, especially the short-circuit failure to take timely measures may last for a long time. The smaller the short-circuit loss, the smaller the failure probability. Of course, the smaller the loss, the more in line with the requirements of energy saving.
The company mainly designs and manufactures AC /DC, DC/DC and DC/ AC modular switching power converters. Products have strong competitive advantages in technology and quality, and are widely used in post and telecommunications equipment, base stations and user power systems, monitoring systems, railway signals, power systems, medical equipment, instrumentation, industrial automation control, aerospace, military industry and other fields.