Soft-Switching Techniques for Single-Inductor Multiple-Output LED Drivers

Although a plethora of prior-art single-inductor multiple-output (SIMO) light-emitting diode (LED) drivers have been reported, they remain inadequate for resource-constraint drone applications due to compromised power efficiency and weight. This article proposes a monolithic SIMO red–green–blue–white LED driver that features high power efficiency and light weight. The former is obtained by employing our proposed soft-switched cross-current-eliminated controller and proposed on-chip bidirectional current sensor. The latter is achieved by means of employing a tiny inductor attributed to boundary conduction mode and high switching frequency. To the best of authors’ knowledge, the proposed SIMO LED driver is the first-ever design that features soft switching for all power switches and innate elimination of current cross-regulation. In comparison with the state-of-the-art designs listed in the benchmark table, the proposed design features the highest power efficiency of 96.2%, smallest output inductor of 820 nH, shortest LED current settling time of 900 ns, and the highest switching frequency of 2 MHz.