PCB-embedded Integrated Coupled Inductor Design For Integrated VR in Smartphone Application
In this paper, a novel, four-phase integrated coupled inductor structure is proposed shown in Fig. 2(a). Due to negative coupling, the dc flux in the core and inductor footprint are reduced. By integrating four inductors into one magnetic core, the inductor footprint is further reduced by flux cancellation without increasing inductor loss. By optimizing this new inductor structure with the help of a finite element tool, 70% inductor loss reduction and 40% footprint and thickness reduction are realized compared with previous inductor design. Furthermore, to demonstrate the feasibility of integrating active components with proposed inductor structure, the inductor samples are fabricated and embedded into PCB as shown in Fig. 2(b). By using PCB-compatible magnetic material, the inductor performance is not impacted by PCB integration. Finally, a very small footprint (<14 mm2) and low profile (0.6 mm) are achieved by this four-phase PCB-embedded, integrated coupled inductor.