An All NMOS KY-Boost Converter With Double Injection Control for Fast Line and Load Transient Response

Abstract

In this paper, a KY-boost converter with double injection control for the mobile devices is presented. The conventional boost converter suffers from several issues, including large output voltage ripples and slow line and load transient responses. A KY-boost converter is a good candidate to overcome the above drawbacks which has buck-like characteristics. A KY boost converter integrated circuit (IC) is proposed in this paper to achieve better line and load transient responses with the smallest chip size compared with the prior arts. A double injection control is proposed in the KY-boost converter to improve line transient response without affecting loop gain and load transient response. Besides, the issues of start-up and larger chip size for KY converter are improved by the all NMOS power stage design with cross-coupled gate driver. The proposed KY-boost converter IC was fabricated with 0.18- $\mu $ m CMOS process, and the overall chip area is 1.1 mm2 including pads. The measured peak efficiency of this work can achieve 92.95%. When the proposed double injection control is enabled, the output voltage deviation during line transition can be reduced by more than 200% from 80 mV to 36 mV compared with input voltage feedforward control.