A novel primary current detecting concept for synchronous rectified LLC resonant converter

For the medium power level adapter applications with high output current and low output voltage, the synchronous rectifier is always necessary for LLC resonant converter obtaining high conversion efficiency. This document presents a novel primary current detecting concept for the current driving of SRs, which can help to reduce the complexity of secondary-side PCB layout and the conduction loss of current sensor when with the conventional secondary current detecting method.