High efficiency hybrid current balancing method for multi-channel LED drive

In this paper, a novel hybrid current balancing method for multi-channel LED drive based on quasi-two-stage converter are proposed. In the proposed structure, each output module has two outputs and their output currents can be balanced by a capacitor based on charge balancing principle. A switching mode current regulator is adopted for each output module to balance the currents of the output modules. Since the current regulator only process part of the total output power, the cost is low and the efficiency is high. The proposed method combines the advantages of passive and active current balancing method, which is simple and flexible for load expandability. Performance of the proposed method is validated by the simulation and experimental results from a 120W prototype with four LED strings.