A high efficiency current mode step-up/step-down DC-DC converter with smooth transition

Author

Ma, Yanzhao ; Cheng, Jun ; Chen, Guican

Author_Institution

Sch. of Electron. & Inf., Xi´´an Jiaotong Univ., Xi´´an, China

fYear

2011

fDate

25-28 Oct. 2011

Firstpage

108

Lastpage

111

Abstract

This paper presents a current mode step-up/step-down DC-DC converter with small output voltage ripple, high efficiency, and fast transient response. When the input voltage is much higher or lower than the output voltage, the converter operates in peak current pure buck mode or valley current pure boost mode to reduce the switching loss. Double lossless current sense circuits are adopted to improve the current sensing speed. Two transition modes are introduced between buck mode and boost mode to alleviate output voltage ripple. Moreover, the average inductor current is also minimized to reduce the conduction loss in two transition modes. The converter has been designed with a 0.5μm CMOS process. The recovery time is less than 200μs with a switching frequency of 400 kHz when the load current switches between 300mA and 600mA. A peak efficiency of 94% is achieved, and the maximum output voltage ripple is less than 25mV.

Keywords

CMOS integrated circuits; DC-DC power convertors; transient response; CMOS process; current 300 mA; current 600 mA; current mode step-up/step-down DC-DC converter; current pure buck mode; double lossless current sense circuits; frequency 400 kHz; output voltage ripple; size 0.5 mum; smooth transition; transient response; valley current pure boost mode; CMOS integrated circuits; CMOS technology; Multiaccess communication; Patents; Pulse width modulation; Radio frequency; Switches;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC (ASICON), 2011 IEEE 9th International Conference on

Conference_Location

Xiamen

ISSN

2162-7541

Print_ISBN

978-1-61284-192-2

Electronic_ISBN

2162-7541

Type

conf

DOI

10.1109/ASICON.2011.6157134

Filename

6157134