Investigation On Cascade Current-fed Push-pull DC/DC Converter

Due to the lower working voltage and larger working current of next generation microprocessor, the voltage regulator modules(VRM) with input voltage of 5V and 12V are not suitable for the situation. Thus, it is necessary to raise VRM's input voltage to 48V in the future. It can cut down input current, hence dissipation on bus, resulting in enhancing of efficiency and greatly reducing of the volume of input filter.This paper firstly analyses the current status, common topology and future development of VRM, and bring forward the concept of Cascade Current-fed DC/DC converter based on those facts. And then the detail operation principles and working process of the Buck and Push-Pull Cascade current-fed DC/DC converter and the Interleaved Buck and Push-Pull Cascade current-fed DC/DC converter are introduced. The design principles of the Buck and Push-Pull Cascade current-fed DC/DC converter and the Interleaved Buck and Push-Pull Cascade current-fed DC/DC converter together with their control loops are also presented. At the last, the experiment results of two 48V in and 3.3V/10A out prototypes using these two topologies are presented and compared with each other.