Design and development trends of power modules

In recent years, the demand for power modules has continued to develop towards high power density, high efficiency, high current and low voltage. The design of isolation modules mainly uses traditional circuit topologies such as single-ended flyback, single-ended forward, forward-flyback combination, push-pull, and bridge conversion. Non-isolated modules use BUCK, BOOST, etc. Regarding high efficiency, in order to improve efficiency, various soft switching technologies can be combined, including passive lossless soft switching technology, active soft switching technology, such as ZVS/ZCS resonance, quasi-resonance, constant frequency zero switching technology, zero voltage, and zero current Conversion technology and synchronous rectification technology, etc. Regarding large currents, multi-phase conversion can be used to increase the output current.

With the continuous advancement of semiconductor process technology, chips and components on PCB boards have higher functions, faster operation speeds, and smaller sizes, driving power management ICs to provide lower and more precise voltages, larger currents, and more stringent requirements. Voltage feedback accuracy, higher efficiency performance. On the other hand, the application fields of power management ICs continue to expand and deepen, achieving better control functions, smarter control loops, faster dynamic response characteristics, and simpler peripheral layout designs. Therefore, simplifying design, digitalization, modularization and intelligent power IC are inevitable development trends.

Power modules are a development trend of switching power supplies. With the development of power supply technology, it is possible to achieve modularization of switching power supplies. Power supply is very important in system design, because if the power supply is not good, it will lead to instability of the electronic equipment system. Let’s discuss the design of power modules and briefly analyze future development trends.

In addition to developing new components and new technologies, how to combine and optimize these existing technologies to achieve high power density and high efficiency is also a major challenge in module power supply design. Taking brick power modules as an example, the current mainstream is 1/8 brick power module. To further optimize 1/16 brick power module products, the efficiency must be further improved.

Also, the change of power supply products from 1/8 brick to 1/16 brick is not just a matter of volume. The change of a product involves many aspects. High power density puts forward higher requirements for R&D, production technology, quality assurance, etc. How to maintain high power output while reducing product volume is a very difficult challenge.

At present, power modules have been miniaturized, but whether they can be made even smaller is a great challenge to process and system design. In some system designs, there are restrictions on module height, and traditional power modules obviously cannot meet the requirements. Therefore, making the product thin and having a thin power supply for every parameter is also a major challenge.

In terms of large current, this was difficult to achieve in the past because the product was too small and the current was too large. However, with the development of technology, many manufacturers have launched high-current products, and their sizes are getting smaller and smaller. In terms of EMI, because electronic equipment is widely used, interference is becoming increasingly serious. In order to reduce system noise and interference, high EMI must be improved.

In terms of improving efficiency, saving energy and reducing consumption, from a circuit perspective, there are two aspects of losses that need to be considered. One is the MOS tube switching loss, and the other is the battery conversion efficiency of the inductor as an energy storage device. These two parts of losses make you lose money. This method overcomes the shortcomings of traditional power supplies, and it is difficult to achieve an efficiency of more than 94%. Because your MOS tube is not an ideal switch and the inductor is not an ideal inductor, there will definitely be losses. In the future, product size, shape, efficiency, and EMI will be the primary challenges facing power supply development.

As electronic equipment develops towards miniaturization, the space left for module power supply is usually very limited, and some systems are even closed. Therefore, heat dissipation becomes the first issue to be considered. Improving power efficiency and reducing heat loss are related to the stable operation of the power module and the reliable operation of the entire system.

In the fields of railways, medical treatment, military industry and other fields, the demand is growing. Because it involves public transportation, personal safety and other issues, the first consideration is the high reliability of the module, work safety and other requirements. The power module must be able to work normally for a long time under severe vibration or harsh environment, and no errors are allowed. This is a challenge to the technology development and production processes of domestic power module manufacturers. Both development and production lines must be very reliable.

For power supply sequencing and tracking technology, designers have traditionally built separate onboard circuits to handle the voltage sequencing problem, which uses a lot of components and takes up a lot of space. Some power supply manufacturers have now integrated this technology into chips or modules to make it easier for system designers to complete their designs.