With the rapid development of power electronic technology and switching industry, power electronic equipment and people's work and life increasingly close relationship, and electronic equipment are inseparable from reliable power supply, into the 1980s computer power fully realized switching power supply, the first to complete the replacement of computer power, into the 1990s switching power supply has entered a variety of electronic, electrical equipment fields. SPC switches, communications, electronic testing equipment power supplies, control equipment power supplies, etc., have been widely used switching power supplies, but also promote the rapid development of switching power supply technology. Switching power supply is a power supply that uses modern power electronics technology to control the time ratio of switching transistors to turn on and off to maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. Compared with the switching power supply and the linear power supply, the cost of both increases with the increase of the output power, but the growth rate of both is different. The cost of linear power supply at a certain output power point is higher than that of switching power supply, which is a cost reversal point. With the development and innovation of power electronics technology, switching power supply technology is constantly innovating, and this cost reversal point is increasingly moving to the low output power end, which provides a wide range of development space for switching power supply.

High-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and the switching power supply into a wider range of applications, especially in the field of technology applications, to promote the miniaturization of technology products, lightweight. In addition, the development and application of switching power supply is of great significance in saving energy, saving resources and protecting the environment.