28.3 A 12-28V to 0.6-1.8V Ratio-Regulatable Dickson SC Converter with Dual-Mode Phase Misalignment Operations Achieving 93.1% Efficiency and 6A Output

The USB PD standard for powering portable computing devices is continually advancing. The Adjustable Voltage Supply (AVS) mode enables supply-end adjustments to fulfill load requirements, optimizing energy efficiency. Power converters for point-of-load supply need to accommodate a wider input voltage range while maintaining high efficiency, compact size, and ample load capacity. Various hybrid switched-capacitor (SC) topologies [1–7] have been proposed to address higher input voltages and ensure superior performance at higher voltage conversion ratios (VCRs). Many designs incorporate one or more power inductors along the primary output current path, such as flying-capacitor (C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</inf> ) multi-level, hybrid Dickson [7], and DSD-based converters [5, 6]. Consequently, the inductors dominate system volume due to conduction loss concern, while the number of inductor branches limits load capacity. In this work, we introduce a 12-to-28V input, 0.6-to-1.8V output ratio-regulatable (R 2 ) Dickson SC converter. It delivers a 6A load current with 81.9% efficiency and an overall peak efficiency of 93.1%, employing a single 4.7μH inductor of 9.6mm 3 . In addition, it retains the multi-branch output conduction feature of Dickson topology, as shown in Fig. 28.3.1, to boost the output current while maintaining efficiency. Key contributions of this design encompass: 1) Introducing a concept that embeds a current-regulating function using an inductor in an SC power cell, enabling VCR regulation capacity with a Dickson converter. 2) Proposing a switching phase misalignment operation mode to mitigate the current gathering issue of C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</inf> due to the change/discharge cycle imbalance. 3) Implementing a compact gate driving scheme that employs an on-chip charge pump to reduce external bootstrap capacitor (C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BST</inf> ).