Fast Transient Response of GaN-Based Hybrid Dickson Converter using Quasi-Fixed-Frequency Control for 48-V-to-1-V Direct Conversion in Automotive Applications

Abstract

This paper demonstrates a GaN-based 6-to-1 hybrid Dickson converter with a fast transient response for 48-V-to-1-V direct conversion in automotive applications. The fast transient response is accomplished using a quasi-fixed-frequency capacitor-based valley-current on-time control scheme. Compared to inductor-based current control schemes, the proposed method 1) offers fast dynamic performance with near deviation-optimal response, 2) improves the efficiency of the system by eliminating inductor-current sensing resistive loss, and 3) enables self-balancing of the flying-capacitor voltages. The performance of the proposed method, subject to load and input voltage transients, is verified using a 40-W 93.3%-peak-efficiency 1-MHz prototype.