A Novel Zero-Voltage-Detector for Buck Converter in Discontinuous Conduction Mode(DCM)

This paper presents a Zero-Voltage-Detector (ZVD) circuit for buck converters working in discontinuous conduction mode (DCM). A novel comparator with pre-amplification property is proposed to provide fast sensing and comparison to optimize the switching timing of power transistors, hence minimizing the power losses caused by the reverse inductor current. The proposed DCM buck converter is fabricated using 0.18um CMOS technology with a chip area of 0.9mm ² . The simulated sensing delay of the proposed ZVD is only about 6ns. It achieves $\gt 85$% power efficiency for load currents of $\gt 10$ mA when the input and output voltages are 3.3V and 2.4V respectively.