A capacitor-free single-inductor multiple-output LED driver

This work presents a promising approach for driving multi-color RGBW high current LEDs for general lighting. Based on a DC input voltage, the applied topology correlates on a DC-DC flyback converter. Physical advantages in LED applications compared to resistive electrical load open room for elementary changes in the converter topology, which makes the presented work superior to state-of-the-art LED drivers in energy-efficiency, complexity, form-factor and cost. The presented capacitor-free single-inductor multiple-output LED driver offers multiple output voltages in order to gain high efficiency. Besides that, a single inductor is used to supply multiple outputs, without the necessity of capacitors. The presented work has been developed in a 0.18 μm technology. With a total output power of 6.5 W, the proposed LED driver light output is up to 600 lm, which is comparable to a standard 60 W light-bulb. The light output is related to a modern Retrofit LED lamp, but also has the enhancement of creating dimmable and tunable white colors.