JSSC 2019第4期Power ManagementBuck Converter

A Hybrid Structure Dual-Path Step-Down Converter With 96.2% Peak Efﬁciency Using 250-m Large-DCR Inductor

采用混合结构的双路径降压转换器，峰值效率达96.2%，解决传统降压转换器功率损耗问题。

250mΩ电感，峰值效率96.2%，功率损耗降低至传统方案的30%

双路径降压转换器功率效率移动电源管理IC混合结构飞电容

▸创新点1：混合结构（电感与飞电容结合）——该方法创新通过结合电感和飞电容的混合结构，有效降低了传统降压转换器的功率损耗，特别是在高负载电流下显著提升了效率，实现了96.2%的峰值效率。

▸创新点2：双路径并行供电——这一电路创新通过双路径并行供电机制，分散了电流路径，减少了单一路径的电流密度，从而降低了电感DCR导致的功率损耗，总寄生电阻功率损耗降低至传统方案的30%。

▸创新点3：降低电感DCR导致的功率损耗——通过优化设计和双路径供电，放宽了对电感DCR的规格要求（使用250mΩ高DCR电感），降低了制造成本和体积，同时保持了高效率。

▸创新点4：宽负载和转换比范围的高效率——系统创新体现在DPDC在宽负载电流（ILOAD）和宽转换比（VOUT/VIN）范围内均表现出显著高于传统降压转换器的效率，适用于移动电源管理IC的多样化应用场景。

Abstract

A dual-path step-down converter (DPDC) is pre- sented for achieving high power efﬁciency in the mobile power management ICs (PMICs). Adopting a hybrid structure using one inductor and one ﬂying capacitor, the proposed DPDC supplies a load current via two parallel paths, relieved an intrinsic problem of the conventional buck converter (CBC) topology, which is a signiﬁcant power loss from a large DCR of the inductor ( R DCR). Therefore, DPDC achieves a high power efﬁciency and thus also reduces the heating problem, which is another critical issue in the mobile set. Moreover, DPDC can shrink the volume of the PMIC set with a low manufacturing cost by alleviating an R DCR speciﬁcation of the inductor. In this paper, although a 250 m /Omega1of large RDCR inductor is used for our measurements, a 96.2% of peak efﬁciency was achieved and the power loss of total parasitic resistances can be reduced to up to 30% of that of CBC. Moreover, according to our measurement plots, it is veriﬁed that DPDC achieves the efﬁciency notably higher not only in a wide load current ( I LOAD) range but also in a wide conversion ratio ( VOUT/VIN) range, compared to CBC.