Gate-drive circuit for zero-voltage-switching half-and full-bridge converters

Resonant techniques like zero-voltage switching (ZVS) and zero-current switching (ZCS) are widely applied to raise the switching frequency and efficiency of converters. An important subclass of converters using resonant techniques is formed by ZVS half- and full-bridge converters. While different varieties of this subclass of converters have been reported, the gate-drive circuit is seldom described. In this paper, a new gate-drive circuit applicable in ZVS half- and full-bridge converters is proposed. The circuit shows excellent features such as transformer isolation, no ringing of the gate-source voltage of the switches, programmable dead time, no active components besides one low-side driver, insensitivity to component value variation, negative gate-source voltage at switch-off, and low drive power. Moreover, the circuit can be used in variable-frequency applications. The theoretical results obtained are verified by experiments.