An Adaptive Mode-Hopping, Self-Oscillating DC-DC Converter with Full Inductor-Current Sensing Technique

• Main Authors: Kai-Jie Chuang, 莊凱傑
• Other Authors: Sau-Mou Wu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/58424649687732511055

碩士 === 元智大學 === 電機工程學系 === 97 === An adaptive mode-hopping and self-oscillating DC-DC converter is presented in this thesis. This converter had fast transient response and system stable response. A multi-detector and a full inductor-current sensing technique area are applied on the loop controller of this DC-DC converter. The inductor current level is detected by active full inductor current sensor, so as to limit the maximum and minimum inductor current. Three control modes are constructed for reaching the best efficiency distribution to load condition. The proposed adaptive mode-hopping mechanism activates the converter to switch between CCM and DCM modes when necessarily during normal operation. The idle-mode is utilized at every light load to reduce the switching losses and enhance the conversion efficiency. It is deduced from simulation results that the efficiency of the DC-DC converter can be up to 93.5% on the conditions that the maximum peak-to peak output voltage ripple is less than 22mV and the output current ranges are between 50mA and 350mA. The DC-DC converter operates at a frequency ranging from 0.3 to 1.7MHz and a supply voltage ranging from 2.4 to 4.2V. The DC-DC converter was implemented in TSMC 0.35-μm 2P4M CMOS process with die size of 1.97 mm2.