MAXIMIZE EFFICIENCY METHOD FOR RESONANT CONVERTER WITH SELF-ADJUSTING SWITCHING POINTS

摘要

A maximize efficiency method for resonant converter with self-adjusting switching points is disclosed. The method is operated by a resonant converter, which comprises a transformer and a field effect transistor (FET). When the transistor is turned on, energy is stored in the transformer. When the transistor is turned off, a resonant signal is generated at a drain of the transistor. At this time, a suitable trigger time has to be found to turn on the transistor, so as to reduce switching power loss. The method measures the slope of the resonant signal at the trigger time. This is used as a reference to adjust the next cycle's trigger time. If the slope is negative at the time of trigger, a delta time is added to the trigger time in the next cycle, If the slope is positive, a delta time is subtracted from the trigger time for the next cycle.