Patent ID: 6256214
Filing Date: 2001-07-03
Classification: H02M,Y02B

Abstract:
A self-driven synchronous rectifier circuit for a power converter, said circuit comprising:a first transformer having a primary winding and a secondary winding, said secondary winding having a first terminal and a second terminal;a first synchronous rectifier coupled to said first transformer secondary winding first terminal and having a control terminal floating relative to ground;a first drive circuit coupled to said first synchronous rectifier floating control terminal and controlling said first synchronous rectifier;a first control signal coupled to said first drive circuit, wherein said first control signal controls the first drive circuit as a function of a voltage polarity reversal across said first transformer, wherein said first control signal is derived from said first transformer secondary winding second terminal;a second synchronous rectifier coupled to said first transformer secondary winding second terminal and having a control terminal floating relative to ground;a second drive circuit coupled to said second synchronous rectifier floating control terminal and controlling said second synchronous rectifier; anda second control signal coupled to said second drive circuit, wherein said second control signal controls the second drive circuit as a function of a voltage polarity reversal across said first transformer.