An improved chipset of synchronous rectification controller applied in isolated topology

This paper begins by illustrating the issue of conventional synchronous rectification, vertical conduction, which largely reduces the efficiency, affects safety utilization of synchronous rectification controller. Next, the improved chipset is presented, including the master chip and slave chip, wherein the former is a current-mode pulse-width modulated (PWM) signal controller with pre-pulse-width modulated (PPWM) signal and the latter is a controller with the function of synchronous rectification drive and voltage feedback. To dig deeply into the idea exhibited from this improved topology, modulation of master chip signal and demodulation of slave chip signal are emphasized. Phenomenon of vertical conduction is eliminated in this topology so that the utilization could be reliable and simple, the efficiency could be enhanced. Finally, an example is presented to describe the use of the chipset.