A 32-A, 5-V-Input, 94.2% Peak Efficiency High-Frequency Power Converter Module Featuring Package-Integrated Low-Voltage GaN nMOS Power Transistors

A buck converter using a low-voltage GaN nMOS power transistor with 5-10x superior switching figure-of-merit over Si laterally-diffused MOS (LDMOS) and stacked CMOS at 5 V has been employed to build a high-frequency (3-20 MHz), high-density (9 A/mm(2)) buck converter for high-performance-compute applications. The GaN-based converter is co-packaged with a CMOS Companion Die on a 4 mm x 4 mm package and employs on-die gate clamps to minimize the impact of package parasitics for high efficiency. For 5-V input to 1-V output conversion, the converter achieves 94.2% peak efficiency at 3.1-MHz switching frequency with a 40-nH inductor, and >80% peak efficiency at 20 MHz with an air-core inductor.