A Multi-Output Multi-String High-Efficiency WLED Driver Using 40 nm CMOS Technology

In this work, a multi-independent-output, multi-string, high-efficiency, boost-converter-based white LED (WLED) driver architecture is proposed. It utilizes single inductor main switch with common maximum duty cycle controller (MDCC) in the feedback loop. A simple pulse skipping (PSC) utilized each high-side of multiple independent outputs. Despite presence outputs, over-voltage protection (OVP) circuit used at output to protect from any voltage above 27 V. An open strings addressed, addition LED’s short-circuit conditions. Excellent current matching between achieved, despite low ON-resistance (Rdson) transistors 40 nm process. Most circuits are designed digital CMOS logic overcome extreme process variations node. Compared parallel topology, 50% improvement efficiency achieved relative extremely unbalanced strings. Three proposal, but more can be supported same topology. Each string driven by 25 mA sink. input 3.2–4.2 V and an up supported.