The Research Of Synchronous Rectification In Low-voltage And High-current High-frequency Switching Power Supply

Along with the rapid development of information technology, communication technology and micro electronic technique, and the popularization of IC chip and DSP (digital signal processor), the performance of regulated power supply has become increasingly demanding. Low-input-voltage is helpful to reduce the power attenuation of the equipments and to increase the speed of high-speed processing systems. However, low voltage output and consequent high current means low efficiency for switching power supply. Currently, the method to reduce rectifier loss based on synchronous rectification is used generally. Optimizing circuit topologies, driving synchronous rectifier diodes reasonably and raising the efficiency of low-voltage high-current DC-DC converters have now become the power electronic technology research hot spot.This paper gives an analysis and study on the circuit topologies and synchronous rectification of various kinds of low-voltage high-current DC-DC converters. The result shows that optimum combination is SR-active clamp forward converter. So this paper does an in-depth research in SR-active clamp forward converter and proposes a simple driving method. Through calculating and selecting the parameters of circuit components, an actual circuit is designed and simulated by the Saber software.