A 95% Peak Efficiency Modified KY (Boost) Converter for IoT with Continuous Flying Capacitor Charging in DCM

Abstract

DC-DC converters are required to achieve high efficiency over wide loading range and compact size for loT applications as shown in Fig. 1(a). However, many designs applied more than one control method to satisfy such requirements [1,2,4,5], which demands complex control system that involves mode selection subsystem, causing efficiency penalty and large chip area. The conventional boost converter has discontinuous output current, which degrades efficiency and output voltage ripple. As a hybrid converter with switched capacitor and inductor, the KY converter overcomes the above drawbacks. However, the charging time of the flying capacitor is seriously limited by the inner operation logic in discontinuous conduction mode (DCM) operation, resulting in small output loading capability and low efficiency.