Method for controlling a synchronous rectifier and synchronous rectifier controller

摘要

A synchronous rectifier control method to rectify a voltage from an inductance (2; 2a) is provided, the induction of which is periodically built up and reduced. The rectifier comprises a switch (20; 20b) to be turned ON during a second time period of reduction of the induction, and to be switched OFF during a first time period of building up the induction of the inductance (2; 2a). The method comprises the steps of detecting the induction value build up during said first time period; determining the stop time for switching OFF said switching means (20; 20b) in the second time period depending on the induction value detected at the end of the first time period and the respective absolute value of a control voltage being proportional to said voltage supplied by the inductance (2; 2a) during the second time period. Further, circuits to implement the method are provided like a synchronous rectifier controller, a synchronous rectifier or a power converter. IMAGE