Design Of The DC-DC Switching Power Supply Using Push-pull Driver

With the development of semiconductor technology and electronic technology, switching power supply is getting smaller volume, lighter quality, higher efficiency, more and more excellent reliability, and has been widely applied to all the aspects of life. DC-DC switching power supply is a very common form of switching power supply, therefore, for DC-DC switching power supply, the study of the topological structure and feedback circuit have become important parts of understanding the switching power supply.This paper analyzes the working principle, efficiency, advantages and disadvantages of DC-DC switching power supply, designing a push-pull DC-DC switching power supply with constant output voltage. With TI’s high speed PWM controller UC3825,this paper gives the block diagram of the.DC-DC switching power supply, designing the controller, push-pull driver, rectifier and filter, feedback control circuits in detail and discussing the type selection of transformer, switch transistor, rectifier diode. The result of the push-pull DC-DC switching power supply prototypeing test shows the push-pull DC-DC switching power supply prototype’s transfer efficiency can reach above 85% with output power from 100 W to 300 W.