A Monolithic 3:1 Resonant Dickson Converter with Variable Regulation and Magnetic-Based Zero-Current Detection and Autotuning

In the last decade, hybrid and resonant switched-capacitor (SC) converters have gone from a relatively unexplored concept to one that is gaining widespread adoption in a range of applications [1]. However, despite capabilities to operate efficiently with small passive components, extending these topologies to use silicon-integrated inductors remains challenging [2]–[6]. This work presents a nominally 3:1 step-down resonant Dickson converter targeting low-voltage applications and providing several advances compared to past work. Shown in Fig. 18.4.1, the design uses a merged electromagnetic spiral resonator. As in [3], the merged resonator combines flying capacitance and inductance into a single structure. Shared die area reduces size overhead but also provides current ballasting which counteracts strong high-frequency (skin and proximity) loss effects, enabling high-frequency operation with better efficiency and power density. Improvements from past work include: 1) an extension to higher conversion ratios, which motivates new gate driving and bootstrapping strategies; 2) leveraging magnetic coupling in a Dickson architecture to improve inductance utilization and reduce resonant-frequency variation in phase half cycles; and 3) the design of integrated zero-current (resonant-frequency) autotuning using an on-chip magnetic current-sensing scheme.