Five-Level Dynamic Hybrid DC-DC Converter

In this paper, a topology for a hybrid 5-level buck converter is studied and implemented. The circuit architecture and operating principles are shown. The topology uses two flying capacitors to support up to five voltage levels at the inductor input, enabling several operation regions. Additionally, modulation of the duty cycle is possible. This allows wide coverage of output voltage values and a minimization of the output voltage ripples while using a small, low quality factor inductor, a suitable feature for on-chip and portable DC-DC converters. The test circuit is simulated and implemented off-chip using commercially available components to verify the functionality of the working principle. Under the same experimental test conditions, the 5-level hybrid converter achieves up to 15 % efficiency improvement over a traditional and a 3-level hybrid buck converter at selected conversion ratios and load currents.