How to increase the operating frequency of power adapters

The speed of the power adapter theoretically has zero loss and minimal noise, which is a way to increase the operating frequency of the power adapter. The megahertz level converter using resonant switching has been put into practical use, and the technological demand and development trend of power adapters can be summarized as follows:

① Miniaturization, thinning, lightweighting, and high cost: The volume and weight of power adapters are mainly determined by energy storage components (magnetic components and capacitors). Therefore, the miniaturization of power adapters is essentially to minimize the volume of energy storage components as much as possible. In the following four aspects, the increase in switching frequency can not only effectively reduce the size of capacitors, inductors, and transformers, but also suppress downward variation and improve the dynamic performance of the system. Therefore, high-frequency is the main development direction of power adapters.

② High reliability - Power adapters use ten times fewer components than continuous working power supplies, thus improving reliability. From a lifespan perspective, the lifespan of components such as electrolytic capacitors, optocouplers, and exhaust fans determines the lifespan of the power supply. So, we need to focus on design and use as few components as possible to improve integration. This not only solves the problems of complex circuits and poor reliability, but also increases protection and other functions, simplifies the circuit, and improves the average time between failures.

③ One of the drawbacks of low noise power adapters is that they produce a lot of noise. Simply pursuing high frequency will also increase noise. Adopting partial resonant conversion circuit technology can theoretically increase frequency and reduce noise. So, minimizing the impact of noise as much as possible is another development direction for power adapters.

④ Using computer-aided design and control - using CAA and CDD technology to design the latest transformation topology and optimal parameters, making the power adapter have the simplest structure and optimal operating conditions.

Introducing microcomputer detection and control into the circuit can form a multifunctional monitoring system that can detect, record, and automatically alarm in real-time. The development of power adapters has always been closely related to the development of semiconductor devices and magnetic components. The implementation of high-frequency technology requires corresponding high-speed semiconductor devices and high-performance high-frequency electromagnetic components. The development of new high-speed devices such as power MOSFETs and IGBTs, the development of low loss magnetic materials for high-frequency use, the improvement of the structure and design methods of magnetic components, the increase of the dielectric constant of filter capacitors and the reduction of their equivalent series resistance have always played a huge driving role in the miniaturization of power adapters. In short, in the field of power adapter technology, people are researching low loss circuit technology while developing new components. The two mutually promote and drive the development of power adapters towards small, thin, high-frequency, low-noise, and high reliability with an annual market growth rate exceeding double digits.