Load-Independent Hybrid Resonant Converter for Automotive LED Driver Applications

In this article, a hybrid resonant LED driver for automotive illumination applications is proposed. The employed
LCC
resonant network provides load-independent output current characteristic and accomplishes full soft-switching operation of the semiconductor devices within the desired input voltage range. To provide constant frequency operation and nonpulsating input current, a continuous conduction mode boost structure is merged into the resonant network. Also, the analog dimming capability range of 50%–100% is attained for the LED string by adjusting the main switches operating duty cycle. Detailed theoretical analysis of the proposed LED driver is presented. To verify the analysis and effectiveness of the proposed topology, a 40-W laboratory prototype is designed and implemented for the input voltage range between 8–18 V.