A 35 V-5 V monolithic integrated GaN-based DC-DC floating buck converter

The paper presents the development of a GaN DC-DC power converter with a pre-driver module and power device based on a monolithic integrated GaN E/D-mode metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) platform. The pre-driver module with direct coupled field effect transistor logic circuit structure has been monolithically integrated with a GaN power transistor on a Si-based AlGaN/GaN commercial epitaxial wafer. The MIS-HEMTs structure adopts an insulated gate dielectric layer to suppress the leakage current and increase gate voltage robustness. The GaN-based floating buck converter employs a 1 mH inductor and a 9 & mu;F capacitor to achieve 35 V-5 V power conversion. As a result, the pre-driver module is capable of delivering a 10 V driving voltage. GaN monolithic integration of the pre-driver module and power device can reduce the system area in the DC-DC application, which allows for an integrated chip size of 1.8 mm(2).