A Modular Multi-Channel Constant-Current LED Driver with High Frequency AC Square Voltage Bus

A multi-channel constant-current LED driver based on high-frequency AC square voltage is proposed in this paper, which is composed of a high-frequency DC/AC inverter and as many passive LCL-T resonant rectifiers as the number of the output channels. The passive rectifier whose output current is sensed and closed-loop controlled is called master rectifier and all the others are slave rectifiers. Considering the influence of the higher harmonics, the constant-current output performance of the driver is analyzed, and the influence of master channel on slave channel is obtained precisely in this paper. Based on the analysis results, the quantitative design of the parameters has been completed to satisfy the requirement of the slave normalized current. Finally, a 200-W prototype with five constant-current outputs is built to verify the correctness of theoretical analysis.