A MOS gate drive with resonant transitions

A resonant gate-drive circuit for MOS power transistors is described. The gate drive provides quasi-square-wave gate-to-source voltage with low impedance between gate and source terminals in both on and off states. Input capacitance of the power MOS transistor is charged and discharged in a resonant circuit so that switching losses in the gate drive are eliminated. This is particularly important in high-frequency and low-power applications. A detailed loss analysis yields closed-form solutions for gate-drive and total switch losses. These results are used to select the MOS power transistor with minimum losses, and to compare the gate drive with resonant transitions against the conventional gate drive.