2.65 MHz high efficiency soft-switching power amplifier system

Power converters operating at megahertz frequency potentially offer high power density and miniaturization. Their exploitation has been hindered by high switching losses not only in the power stage but also in the gate driver. Gate drivers with square-wave and sinusoidal-wave shapes are analyzed and a new high efficiency soft-switching gate driver with gate capacitive energy recovery is proposed and implemented. The conditions to achieve zero-voltage-switching (ZVS) operation and design considerations for a 2.65 MHz power converter are also presented. It is shown that the 2.65 MHz, 100 W power converter has 92.6% overall efficiency.