| The development of VRM (Voltage Regulator Module) has new target and challenge with the speedy development of information technology. VRM have to adopt new technology in order to meet the ever-changing market and development. So it is important and realistic to study new technology.Two-stage converter can take the place of single stage converter in order to reduce the loss of the bus, the input voltage of which can reach48V and the output voltage can be down to1V.Firstly, this paper introduces the development trend, the present situation and design difficulties of VRM. Secondly, It analyzes the main topology structure based on the development. Then, It also analyzes the core technology to improve the efficiency, which includes synchronous rectifier technology, soft-switching technology and magnetic integration technology. Next, It assures research object that can be called buck and double rectified asymmetrical half bridge based on above introduce. The theory of the topology is analyzed in detail, at the same time, the soft-switching technology and magnetic integration technology are studied. At last, simulation and experiment have been conducted to verify the correctness and feasibility.In this paper, the experimental prototype of Buck and double rectification is designed. The switchs of system can realize soft-switching.and the magnetic integration of post-stage circuit was also designed. The system uses a single voltage closed-loop control. Previous level switch duty cycle was regulated by the output voltage feedback and asymmetric half-bridge works in the open-loop control mode, the duty cycle of which is constant.This topology has advantages of high efficiency and simple control. |
PDF Full Text Request