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

Resonant techniques like zero-voltage switch (ZVS) and zero-current switch (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 beside 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.