A hybrid multioutput divided power converter for LED applications

A novel converter based on the differential connection of a switched capacitor (SC) and buck-boost converter is presented in this article. This converter enables volume reduction while also increasing power processing efficiency by utilizing the high power density of SC converters and partial power processing. The introduced multioutput inverting buck-boost SC converter is presented as a light-emitting diode (LED) driver for mobile applications. The topology is capable of providing current to multiple LED strings at different voltages. A current-balancing technique based on charge matching is developed without the need for external-current-regulating components. Experimental results confirm a reduction in passive volume around 70% compared to conventional topologies for the targeted application while also increasing efficiency over the whole range, with a peak efficiency of 93%. In particular, light-load efficiency is improved up to 20%. The operation of the proposed charge matching control is confirmed through experimental and simulation results.