Using magnetic coupling to improve the bandwidth and phase margin of boost converters

In this paper, a novel technique that significantly improves the dynamic behaviors of conventional boost converter (CBC) with an auxiliary branch has been presented and the small-signal modeling of the proposed converter has been derived and analyzed. The auxiliary branch includes a capacitor, a diode and an inductor which couples with the main input inductor of the conventional boost converter. Thus, the proposed converter is able to move the frequency of the right half-plane (RHP) zero far away (above 1GHz) from the switching frequency (100kHz) to minimize the drawbacks of the RHP zero. Meanwhile, the phase margin of the proposed boost converter increases significantly compared to the conventional boost converter. The application of these techniques will allow the design of high efficiency voltage boost-based regulators with dynamic behavior similar to that of the buck-derived structures.