Design Optimization for LCD TV Power Supply with Resonant Technique

In this paper, a new soft-switching resonant converter with frequency control is proposed and used in LCD TV applications. The proposed resonant converter has the features of frequency modulation operation with fixed duty cycle, zero voltage switching (ZVS), and low voltage stress in the active switches and output diodes. Moreover, it can achieve high power density, high efficiency, low switching losses and low component counts, which make converter operation at low to medium power level feasible. In the paper, optimal design rule of the resonant converter is presented in detail, and a specific example for LCD TV application is designed and implemented to verify its feasibility.