Low-Voltage Stress Buck-Boost Converter with a High Voltage Conversion Gain

The conventional buck-boost converter has the advantages of simple structure, low cost, and the capability to achieve both voltage step-up and down. However, due to the negative impacts of the parasitic parameters of the device, the voltage conversion gain of the conventional buck-boost converter is greatly limited. A low-voltage stress buck-boost converter with a high voltage conversion gain based on a coat circuit is proposed in this paper to address the problem. Similar to a coat that can enhance human’s resistance to cold weather, by adding the proposed coat circuit to the conventional buck-boost converter, not only the range for the voltage conversion can be extended, but also the voltage stresses of the semiconductor components are effectively reduced. In this work, comprehensive analysis on the working principles and performance characteristics of the coat converter are provided. Experimental results are obtained and analyzed to validate of the theoretical analysis based on a 300W closed-loop prototype platform.