A Resonant Gate Driver with Variable Gain and a Capacitively Decoupled High-Side GaN-FET

Abstract

Here we describe a gate-driver with resonant action that minimizes gating loss at high switching frequencies (10-20 MHz) while facilitating variable voltage gain that can exceed the supply rails. The gate voltage swing can be controlled with minimal duty cycle constraints, making this driver capable of meeting the diverse drive requirements of different switch technologies and converter topologies. A prototype uses two small N-channel gallium nitride (GaN) transistors within the drive structure, significantly decreasing parasitics. To do so, a capacitive decoupling technique is used to allow the high-side Nchannel device's 'flying' driver to receive power; a distinct challenge for flying drivers commuting between two variable voltages. The prototype was applied to several high frequency switching devices. Up to a 72% reduction in gating-loss is observed as compared to a conventional hard-charged gate-driver while maintaining rise and fall times <18 ns for the devices tested.

A Synchronous Boot-strapping Technique with Increased On-time and Improved Efficiency for High-side Gate-drive Power Delivery

“…One essential, yet often trivialized aspect of power converter design is the power delivery scheme for the gatedrivers contained therein. While this circuitry is expected to leave a minimal footprint, improvements in this area have not kept pace with the rapidly developing power converter landscape in which higher order topologies eschew simplicity for dramatic performance improvements [1]- [3]; advanced control schemes and assistive circuitry minimize parasitic effects [4]- [6]; and advanced semiconductor devices, such as Gallium Nitride, consume significantly less area for the same switch conductivity while simultaneously boasting reduced parasitics. Subsequently, switching frequencies have been increased, resulting in the ordinarily dominant volume of passive components reducing considerably [7], [8].…”

Reducing COSS Switching Loss in a GaN-based Resonant Cockcroft-Walton Converter Using Resonant Charge Redistribution

“…Several methods have been proposed to address this loss mechanism using resonant and soft-charging techniques within the gatedriver itself (e.g. [12]). Reverse recovery and finite transition time conduction losses can be avoided through use of devices with no intrinsic body diode (e.g.…”

Large Signal Analysis on Variations of the Hybridized Dickson Switched-Capacitor Converter

“…[2]- [5]). As hybridized switched-capacitor (HSC) power converters gain popularity, a significant body of work has emerged which describes SSL mitigation in a variety of topologies, with additional work applying zero-voltage/current switching (ZVS/ZCS) [4], [5], [8], [12]- [14] and advanced gate-drive structures [15]- [19] for further improved switching performance. Previous work has proposed general analytical methods by which switched-capacitor topologies can be assessed as to their eligibility for hybridization, with com- Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org.…”