High-Frequency High Power Density 3-D Integrated Gallium-Nitride-Based Point of Load Module Design

Abstract

The demand for the future power supplies that can achieve higher output currents, smaller sizes, and higher efficiencies cannot be satisfied with the conventional technologies. There are limitations in the switch performance, packaging parasitics, layout parasitics, and thermal management that must be addressed to push for higher frequencies and improved power density. To address these limitations, the utilization of Gallium-Nitride (GaN) transistors, 3-D integrated technique, low-profile magnetic substrates, and ceramic substrates with high thermal conductivity are considered. This paper discusses the characteristics of GaN transistors, including the fundamental differences between the enhancement mode and the depletion mode GaN transistors, gate driving, and the deadtime loss, the effect of parasitics on the performance of high-frequency GaN point-of-load (POLs), the 3-D copackage technique to integrate the active layer with low profile low temperature cofired ceramic magnetic substrate, and the thermal design of a high -density module using advanced substrates. The final demonstrators are three 12-1.2-V conversion POL modules: a single-phase 20 A 900 W/in 3 2-MHz converter using enhancement mode GaN transistors, a single-phase10-A 800 W/in 3 5-MHz converter, and a two-phase 20-A 1100 W/in 3 5-MHz converter using the depletion mode GaN transistors. These converters offer unmatched power density compared to state-of-the-art industry products and research.

Review of State-of-the-Art Integration Technologies in Power Electronic Systems

“…The active devices are soldered on the one side of the PCB or DBC substrate, and a low profile LTCC inductor is placed on the other side of the substrate. This module can operate at up to 5 MHz [117]. The power density of the 3D integrated POL converter can achieve a power density of as high as 1100 W/in 3 , which is around 10 times higher than that of industry products at the same current level.…”

High frequency PWM-controlled current-mode resonant DC-DC converter with boost conversion

“…In this converter, GaN-FETs were utilized as semiconductor switches, which were suitable for high-frequency switching operation. Also, another researches have been proved utilizing GaN-FET for high frequency converter is very practical [2][3][4][5]. Current-mode resonant DC-DC converters are usually controlled by pulse frequency modulation (PFM).…”

Loss Analysis and Soft-Switching Behavior of Flyback-Forward High Gain DC/DC Converters with a GaN FET

“…The authors of [9]- [13] studied the application of EPC enhanced mode GaN devices to MHz Buck converters and LLC resonant converters. They also discussed the impact of GaN device layout, magnetic components and distribution parameters on circuits.…”

“…They also discussed the impact of GaN device layout, magnetic components and distribution parameters on circuits. [13] shows the 3-D Integrated Gallium-Nitride-Based Point of Load Module Design in detail.…”