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

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 mu m 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 0 degrees C to 100 degrees C. The peak power efficiency of the buck converter is tip to 95.5%.