A Fast-Transient Boost Converter with Peak Passive Ripple Mode Control and AC Couple

Abstract

Peak current mode (PCM) control is often used nowadays in boost converters to improve the stability and control bandwidth because of its single pole characteristic. However, the slope of inductor current causes large output voltage deviation and settling time during load-transient. This paper proposes a peak passive ripple mode (PPRM) control with ac couple to solve the aforementioned load-transient issue. PPRM control generates a passive ripple (PR) for modulation and couples output voltage signal by the passive RC circuit to achieve a fast transient response. Thus, the current sensor and active circuits can be eliminated. Small signal models are proposed for proposed controls. The experiment and simulation results verified the superior load-transient response of the proposed control with the best figure-of-merit among the recent papers. Compare PPRM control with ac couple to PCM control, the output voltage undershoot/overshoot during load step-up/down reduces to only 42% and 38%, respectively. The proposed small signal models also match the experimental results.