A Current-Mode CMOS DC-DC Switching Converter with on-chip Current-Sensor

• Main Authors: Chien-Nan Chen, 陳建男
• Other Authors: Po-Ki Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/85539169363340614963

碩士 === 國立臺灣科技大學 === 電子工程系 === 95 === A current-mode CMOS DC–DC converter with integrated power switches and on-chip current sensor for feedback control is presented in this paper. The sensed inductor current, combined with the internal ramp signal, can be used for current-mode DC–DC converter feedback control. In addition, no external components and no extra I/O pins are required for the current-mode controller. The DC–DC converter has been fabricated with the TSMC CMOS digital process. The simulation results show that this converter with on-chip current sensor can operate in 1.5 MHz with supply voltage varied from 4.5 to 3.5 V, which is suitable for single-cell lithium-ion battery supply applications, with a off-chip capacitor and a off-chip inductor. The maximum power efficiency is 94.3% for load current varied from 50 to 500 mA. The supply voltage range of the converter can be adjusted from 3.5V to 4.5V. For line regulation simulation, the output voltage is always stabilized at the preset value with a maximum output ripple of . For load regulation simulation by varying the output current from 0.5A heavy load to 0.1A light load, the maximum output ripple is merely . The combined regulation has been simulated with both line regulation and load regulation, and the maximum output ripple is . There are three supply voltages of 3.8V, 3.6V, and 4V simulated along with process variation to generate a maximum output ripple of . For temperature variation of ~ , the maximum output ripple is . All above results confirm the excellence of the proposed circuit compared with the commercialized chips. The chip size of the proposed circuit is which is merely 53.66% of those of its predecessors. With such tiny size, the proposed converter is excellent for low cost but high efficiency portable applications to greatly enhance the product competitiveness.