A Hybrid Dual-Path Step-Down Converter with 96.2% Peak Efficiency Using a $250\text{m}$ μ Large-DCR Inductor

A dual-path step-down converter (DPNC) is presented for achieving high power efficiency in mobile PMICs. The proposed DPNC supplies a load current $(I_{LOAD})$ via two parallel paths using a hybrid structure with one inductor and one flying capacitor, solving an intrinsic problem of conventional buck converter topology (CBT) which is a significant power loss from a large DCR of inductor $(R_{DCR})$. Therefore, DPNC not only achieves a high efficiency, but also reduces a heating problem. Additionally, DPNC can shrink a volume of PMIC set with a low manufacturing cost, by alleviating a $R_{DCR}$ specification of inductor. Although a $250\text{m}\Omega$ of large-Dcr inductor was used, this paper achieved a 96.2% of peak-efficiency, and the total loss from parasitic resistance of external components was reduced to up to 30% compared to CBT. Furthermore, DPNC achieved much higher efficiency not only in a wide $I_{LOAD}$ range, but also in a wide $V_{OUT}/V_{IN}$ range.