Patent ID: 6031747
Filing Date: 2000-02-29
Classification: H02M,Y02B,Y10S

Abstract:
A switching power supply, comprising:first and second power converter stages coupled in parallel, each of said converter stages comprising:a transformer having a primary winding and a secondary winding;a primary-side power switch connected in series to said primary winding of said transformer; anda secondary-side power switch connected in series to said secondary winding of said transformer;wherein when an output power of said first and second power converter stages is below a first power level, said first power converter stage operates in a hard-switching mode and said second power converter stage is off;wherein when an output power of said first and second power converter stages is greater than said first power level and less than a second power level, said first power converter stage operates in a soft-switching mode and said second power converter stage is off;wherein when an output power of said first and second power converter stages is greater than said second power level, said first power converter stage operates in a soft-switching mode and said second power converter stage operates in a soft-switching mode.