Highly Accurate and Efficient Current-Mode PWM CMOS DC-DC Buck Converter with On-Chip Current-Sensing

Kuo-Hsing CHENG  Chia-Wei SU  Hsin-Hsin KO  

IEICE TRANSACTIONS on Electronics   Vol.E91-C   No.12   pp.1941-1950
Publication Date: 2008/12/01
Online ISSN: 1745-1353
DOI: 10.1093/ietele/e91-c.12.1941
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Electronic Circuits
buck converter,  current-mode control,  PWM,  current-sensing,  high efficiency,  high accurate,  

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In this paper, a high accuracy, high efficiency, and wide current-sensing range current-mode PWM buck converter with on-chip current-sensing technique is presented. The proposed current-sensing circuit uses simple switch technique to achieve high accuracy, high power efficiency, and high line regulation. The test chip is fabricated using TSMC 0.18 µm 1P6M 3.3 V CMOS process. The measurement results show that the buck converter with on-chip current-sensing circuit can operate from 700 kHz to 3 MHz with a supply voltage of 1.5-5 V and the output voltage of 0.5-4.5 V for lithium ion battery applications. The accuracy of the proposed current-sensing circuit is exceeds 89.8% for load current from 50 mA to 500 mA and for temperature from 0C to 100C. The peak power efficiency of the buck converter is up to 95.5%.