Light-load efficiency improving boost converter with the hybrid modulation of hysteresis current mode and burst mode

Abstract

This paper proposes a new method to improve the efficiency of boost converter under light load conditions by using the hybrid modulation of hysteresis current mode and burst mode (HCM-BM). A circuit is designed to satisfy the requirement of adaptive fast switching between HCM and BM. The whole circuit of proposed HCM-BM converter and conventional HCM converter have been built with a standard 0.18-µm CMOS process, respectively. The simulation results show that the proposed converter provides a maximum efficiency improvement of 17% under light load compared with the conventional boost converter. Meantime, it can achieve up to 74% efficiency at 10 µA load.

A wide input voltage range DC-DC Buck converter with dynamically modified ZCD circuit

“…Since the efficiency of DCM is higher than that of FCCM, most synchronous buck converters operate in DCM mode at light load, and the current in the inductor will become zero during this period [8,9,10,11]. In addition, when the system works in discontinuous mode, due to the influence of the internal logic delay, linear delay, and offset voltage setting of the converter, the low power transistor turns off early or delayed before the inductor current drops to zero, which will inevitably lead to the inductor current reverse flow or the body diode of the transistor conducts.…”