Performance Evaluation of Point-of-Load Chip-Scale DC-DC Power Converters Using Silicon Power MOSFETs and GaN Power HEMTs

Performance evaluation of low-voltage silicon and GaN power FETs is presented for chip-scale DC-DC power converter applications. The circuit calculations are based on an improved circuit model for the FET with accurate description of terminal capacitances and on-resistance. It is shown that GaN power FETs combined with silicon MOS power diodes can potentially lead to nearly 82% power conversion efficiency at 25°C for a 12V/1V, 10W DC-DC converter when switched at 5 MHz in a synchronous buck converter topology.