Patent ID: 6061255
Filing Date: 2000-05-09
Classification: H02M,Y02B

Abstract:
A forward converter, comprising:a power transformer having a primary winding connected in series between a first input supply voltage node and a primary side node, and a secondary winding connected across a first and a second secondary side node;a power switch connected between the primary side node and a second input supply voltage node;a first synchronous rectifying device having a control node and operable to conduct current between the second secondary side node and a second output node;a second secondary winding of the power transformer connected between the second output node and the control node of the first synchronous rectifying element;a second synchronous rectifying having a control node and operable to conduct current between the first secondary side node and the second output node;a first winding of a magnetic energy storage element connected between the first secondary side node and a first output node;a second winding of the magnetic energy storage element magnetically coupled to the first winding and connected between the second output node and the control node of the second synchronous rectifying element; anda control circuit operable to turn off the second synchronous rectifying element at a predetermined time in response to a control signal applied to the power switch.