Abstract：A digital control method is proposed to improve the light-load efficiency of the Buck converter with constant on-time (COT) control. Different from the traditional constant on-time control, the proposed method increases the on-time of constant on-time controlled Buck converters at light-load states to reduce the switching loss and improve the light-load efficiency. In addition, the proposed method uses digital control to determine the zero-crossing point of the inductor current based on the switching frequency without adding the external detection circuit, which makes the synchronous switcher work in discontinuous conduction mode (DCM) and reduces conduction loss. The feasibility of the proposed method is verified by theoretical analysis and corresponding experiments.
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2021, Vol. 22 
