Half-Bridge GaN Power ICs: Performance and Application

Abstract

For a variety of switching power topologies, especially modern soft-switching or resonant designs, half-bridge circuits are essential, ubiquitous building blocks. Operating these half-bridge circuits-i.e., providing power and signal to a floating high-side switch at very high frequencies-can shrink magnetics and enable a dramatic reduction in size, cost, and weight while delivering faster charging. However, such frequency increases have eluded the industry for decades as silicon (Si) devices have been too slow and suffered from parasitic impedances between the driver, high-capacitance Si field-effect transistors (FETs), and poorly performing level-shifters or isolators. As a result, most converters still run at 65-100 kHz. This article describes the exploitation of monolithic, laterally integrated, high-voltage, gallium nitride (GaN) technology to create high-efficiency, high-performance, half-bridge GaN power integrated circuits (ICs), and it shows practical achievements in application efficiency, simultaneously with increased switching frequency, which deliver higher power density.