Abstract
The series-stacked architecture provides a method to increase power delivery efficiency to multiple processors by leveraging the inherent voltage step-down properties of series-connected elements. With a series stack, differential power processing (DPP) is needed to ensure that processor voltages remain within design limits, as the individual loads vary. This paper demonstrates a switched-capacitor (SC) converter to balance a stack of four ARM Cortex-A8-based embedded computers. We investigate hard-switched and resonant modes of operation in a ladder SC DPP converter implemented with GaN transistors. Operation within supply limits of each embedded computer is demonstrated in a four-series-stack configuration with realistic computational workloads. Moreover, we demonstrate hot-swapping of individual computers with maintained voltage regulation at all nodes. A peak stack power delivery of 99% is experimentally measured, and DPP switching frequencies from 200 kHz to 2 MHz are demonstrated.
Original language | English (US) |
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Article number | 8718626 |
Pages (from-to) | 3139-3150 |
Number of pages | 12 |
Journal | IEEE Journal of Emerging and Selected Topics in Power Electronics |
Volume | 8 |
Issue number | 3 |
DOIs | |
State | Published - Sep 2020 |
Keywords
- DC-DC power converters
- differential power processing (DPP)
- digital control
- resonant power converters
- switched capacitor (SC) circuits
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering