An LED Driver Connecting a Nested-Type SC Converter and an SI Buck-Boost Converter in Parallel

For light emitting diode (LED) lighting applications, a novel hybrid LED driver with high voltage gains is proposed in this paper. Unlike existing LED sink drivers with series-connected structure, the proposed driver has the switched-inductor and switched capacitor (SISC) topology combining with an SI buck-boost converter and a nested-type SC converter in parallel. In the proposed topology, the LED cathode and anode are connected to the SI buck-boost converter and the nested-type SC converter, respectively. The characteristics of the proposed topology are analyzed theoretically. Furthermore, the validity of the proposed topology is confirmed by simulation program with integrated circuit emphasis (SPICE) simulations and breadboard experiments. The SPICE simulations and experiments reveal that the proposed driver can achieve high voltage gains and flexible controllability of outputs.