High-efficiency DC-DC converters using inductor-current-reduction techniques for wearable and mobile devices

Abstract

This work presents two kinds of DC-DC converters using inductor-current-reduction techniques in power management ICs at mobile and wearable devices. As miniaturization into the forms of mobile and wearable devices is required, the size and capacity of batteries are lowers. Therefore, lifetime and heat dissipation of electric devices become important. Developed DC-DC converters which use inductor-current-reduction techniques based on dual-path structure have high efficiency by reducing conduction loss at large inductor DC resistance(DCR). The first, to achieve higher efficiency than conventional OLED Lamp drivers, the proposed OLED Lamp driver comprises a hybrid step-up topology using dual path and voltage inverting structures and OLED-current-regulation controller which regulates the OLED current at the voltage-conversion stage. The second, proposed buck-boost converter uses a dual path structure so that both buck and boost operations can be performed in one circuit configuration without changing the mode. Also, it exhibits the lowest inductor current level among previous buck-boost converters so that it has high efficiency. Proposed converters are fabricated using a 180-nm BCD process.