Transient Enhanced Mode design based on DC-DC Buck-Boost converter

Abstract

With the rapid development of electronic products, a system may suddenly start operating from a dormant state. In order to provide a stable supply voltage to a system with a rapidly changing load and to improve the transient response of the DC-DC, a Buck-Boost type DC-DC with a Transient Enhancement Mode is proposed, which improves the transient response during load switching and reduces the overshoot/undershoot voltage and recovery time. The oscillator part can respond to different load transients and output different frequency clock signals to finally achieve fast charging and slow discharging of the inductor. The specific circuit design and physical implementation of the proposed method are verified based on a 0.18μm high-voltage BCD process. The test results show that the minimum overshoot/undershoot voltage can reach 40mV and the fastest recovery time can reach 14μs, and the transient voltage and recovery time are reduced by 66% and 88% respectively compared with the DC-DC design without a fast Transient Enhancement Mode.