Multi-String RGBW LED Driver based on a Single-Input Multiple-Output (SIMO) Topology

This study presents the development and evaluation of a buck converter with a Single-Input, Multiple-Output (SIMO) topology tailored for RGBW LED applications. By addressing the challenges of current imbalance and cost in traditional multiconverter RGBW LED drivers, the proposed SIMO solution consolidates the functionality of four independent converters into a single, compact design. Utilizing a 48V input, the prototype delivers outputs of 26.51V, 30.94V, 33.13V, and 34.12V for red, green, blue, and white LED channels, respectively. A hysteresisbased inductor current control ensures high precision and stability across varying loads. Experimental results demonstrate the converter's high efficiency, ranging from 88% to 94%, depending on load conditions and dimming levels, while minimizing artifacts such as the rolling shutter effect through optimized switching strategies. This work highlights the SIMO converter's ability to significantly enhance the cost efficiency, compactness, and performance of RGBW LED systems, marking a critical advancement in LED driver technology.