High switching frequency DC-DC converters are present in many applications where wide regulation bandwidth and high efficiency are needed. A resonant gate driver is presented for improvement of efficiency at light-to-medium load conditions. Gate power losses that are a main contributor to total losses are reduced thanks to energy recovery. A testchip designed in 0.25-mm BiCMOS shows as much as a 30% decrease in power losses compared to a conventional driver at 200 MHz switching frequency. The proposed resonant gate driver is fully integrated with its inductor unlike earlier works. The limitation in the reduction of gate losses is detailed and confirmed experimentally.