Analysis and implementation of dual-output LLC resonant converter

A dual-output LLC resonant converter for LCD-TV applications is presented in this paper. Based on the LLC resonant behavior, the power MOSFETs are turned on at zero voltage switching (ZVS) and secondary rectifier diodes are turned off at zero current switching (ZCS). In the proposed converter, the primary windings of two transformers are connected in series so that the primary currents of two transformers are equal. In the secondary side of transformers, two full-wave rectifiers with dual-output configuration are connected in parallel to share the load current and to reduce the current stresses of the secondary windings of transformers. The principle of operation, steady state analysis and design consideration of the proposed converter are provided in detail. Experimental results based on a laboratory prototype with 12 V/14 A and -12 V/14 A outputs with 92.7% efficiency for LCD-TV applications were provided to verify the effectiveness of the proposed converter.