Dynamic sawtooth compensation (DSC) technique with self-tuning mode selection (SMS) for current-mode Buck-Boost converter

Author

Su, Vi-Ping ; Wang, Shih-Wei ; Lee, Yu-Huei ; Chen, Ke-Homg

Author_Institution

Inst. of Electr. Control Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

fYear

2012

fDate

20-23 May 2012

Firstpage

221

Lastpage

224

Abstract

The current-mode Buck-Boost (BB) converter with the proposed dynamic sawtooth compensation (DSC) technique is able to improve transient response and system stability. To prevent the system switches between buck and boost operations once input and output are nearly equivalent, self-tuning mode selection (SMS) is proposed to decrease output ripple and redundant power consumption by eliminating the mode misjudgment. The duty cycle is decided by the output of error amplifier and sawtooth signal, which can be adequately adjusted to ensure small output ripple and thus to improve efficiency. Besides, the DSC and SMS technique can reduce the inductor current level and the numbers of switching to decrease switching and conduction losses for high efficiency. The converter with the switching frequency of 1MHz was fabricated in 1P3M 0.25-μm CMOS process. The input voltage is in the range of 2.7V to 4.8V for battery-powered devices. The efficiency is higher than 88% when load ranges from 100mA to 400mA.

Keywords

CMOS integrated circuits; circuit stability; circuit tuning; current-mode circuits; inductors; losses; power convertors; switching convertors; transient response; DSC technique; IP3M CMOS process; SMS; battery-powered device; conduction loss; current 100 mA to 400 mA; current-mode BB converter; current-mode buck-boost converter; duty cycle; dynamic sawtooth compensation technique; error amplifier output; frequency 1 MHz; inductor current level reduction; mode misjudgment elimination; output ripple; power consumption; sawtooth signal; self-tuning mode selection; size 0.25 mum; switching frequency; switching loss; system stability; transient response; voltage 2.7 V to 4.8 V; Switches; TV;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems (ISCAS), 2012 IEEE International Symposium on

Conference_Location

Seoul

ISSN

0271-4302

Print_ISBN

978-1-4673-0218-0

Type

conf

DOI

10.1109/ISCAS.2012.6271729

Filename

6271729