A 32-A, 5-V-Input, 94.2% Peak Efficiency High-Frequency Power Converter Module Featuring Package-Integrated Low-Voltage GaN nMOS Power Transistors
Nachiket Desai, Han Wui Then, Jingshu Yu, Harish K. Krishnamurthy, William J. Lambert, Nicolas Butzen, Sheldon Weng, Christopher Schaef, Kaladhar Radhakrishnan, Krishnan Ravichandran, James Tschanz, Vivek De
Abstract
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/mm²) 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.