The article presents an innovative integrated half-bridge resonant power converter that employs zero-voltage switching (ZVS) to minimize switching power consumption and enhance system efficiency. The design utilizes gallium nitride (GaN) devices, integrating both switches and gate drivers on the same silicon substrate in a dual complementary half-bridge configuration. The gate driver uses a direct-coupled FET logic (DCFL) architecture for the high-side drive and leverages the reverse conduction capabilities of GaN transistors to emulate the switching diodes for the bootstrap circuits. It is designed to provide strong current drive capability while minimizing gate ringing. Additionally, it offers negative voltage drive when the power switch is turned off, eliminating leakage current risk. This integration results in a more compact power converter design. The half-bridge resonant buck converter employing the proposed gate driver can deliver an output current exceeding 40 A with an input voltage of 48 V. It achieves a maximum power output of 500 W when converting from 48 V to 12 V, with a peak efficiency of ${9 7. 1 \%}$ at 200 W output power.