Interleaved synchronous flyback converter with high efficiency over a wide operating load range

摘要

The present invention provides a switching power supply which operates at a high efficiency over a wide operating load range. When the output power is below a first power level, the first power converter stage operates in a hard-switching mode and the second power converter stage is off. When the output power is greater than the first power level and less than a second power level, the first power converter stage operates in a soft-switching mode and the second power converter stage is off. When an output power is greater than the second power level, the first power converter stage operates in a soft-switching mode and the second power converter stage operates in a soft-switching mode.