A single-stage LED driver with couple inductor in low input voltage

A single-stage LED is proposed the paper, the LED driver is made of three parts, the first part is a continuous conduction mode (CCM) boost circuit, which make the circuit have a twice voltage gain; the second part is a double tank LLC circuit, which decreases the peak current and improves the efficiency of the system, and here the couple inductor technique is adopted to increase the power density; the third part is the current balancing circuit, which is used to balance the current of different strings. A 35W prototype is proposed in the laboratory to prove the rightness of the analysis, and the efficiency is as high as 95% in the full load state.