Design and Implementation of Hybrid DC-DC Converter: A Review

The advancement in Power Management Integrated Circuit (PMIC) has driven the dc-dc conversion technology into a System-on-Chip (SoC) solutions, leveraging CMOS technology scaling from 180nm to 22nm and on-chip passive element integration. Concurrently, as the applications demand smaller form factor solution towards device portability with optimized power qualities, switched-capacitor-inductor hybrid architectures with fully-integrated passives have become a popular choice for a compact and high efficiency converter solution, in contrast to bulky and discrete component based alternatives. This article reviews the latest advancements in hybrid dc-dc topologies, specifically for low-power applications to address the downsides such as charge sharing loss, high current ripple, limited conversion ratio, low-power density, and efficiency. An overview of capacitor and inductor technology is discussed in terms of on-chip parasitic losses, and miniaturization. A comprehensive comparison in the state-of-the-art hybrid dc-dc converter work is tabulated with power density and efficiency as the primary performance metrics, highlighting their operability in low-power applications. Moreover, a discussion is included with quantified benchmarks to justify the viability of converters, along with the future recommendation of realizing ultra-high switching frequency for smaller footprint inductor and design approach to resolve the current tradeoff bottlenecks.

Automated summary

The advancement in Power Management Integrated Circuit (PMIC) has enabled the development of System-on-Chip (SoC) solutions for dc-dc conversion using CMOS technology scaling and on-chip passive element integration. Switched-capacitor-inductor hybrid architectures with fully-integrated passives have become popular for compact and efficient converter solutions. This article reviews the latest advancements in hybrid dc-dc topologies for low-power applications, addressing challenges such as charge sharing loss and limited conversion ratio, and compares their power density and efficiency performance metrics.