Multiphase driving system for LCD back-light lamps with current balancing feature

This paper presents a multiphase driving system for liquid crystal display (LCD) back-light lamps with current balancing feature. The driving system adopts multiple inverters operated with interleaving fashion to drive cold cathode fluorescent lamps (CCFL), which can reduce input current ripple. Additionally, to prevent current imbalance among lamps, a multiphase transformer is introduced in the proposed system. Compared with the conventional single-phase driving system, the proposed one can have the merit of requiring less number of transformers and lower input current ripple. A three-phase driving system with current balancing transformer has been built, from which experimental results have verified the feasibility of the proposed multiphase driving system.