Design of a Current-Mode Single-Inductor Dual-Output Buck Regulator with High Switching Frequency

• Main Authors: Shen, Chung-Jui, 沈宗叡
• Other Authors: Yeh, Mei-Ling
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/y9fp68

碩士 === 國立臺灣海洋大學 === 電機工程學系 === 103 === 　　In recent years, among the portable electronic products market, the growing demand for smart phone, domestic and foreign manufacturers integrating more modules, and the performance continuing to improve, which make the demand for energy source of mobile phones continues to increase. In order to increase the battery life in heavy load and extend the standby time in light load of products, there must be much stronger power management system to convert energy and achieve energy saving effect. 　　In this thesis, a single-inductor dual-output buck regulator is designed with current mode, power-distributive control, and pulse-width modulation. Because different sizes of power transistors have different power conversion efficiency curves, in order to reduce the switching loss in light load and achieve good conversion efficiencies of pulse-width modulation in light and heavy loads, we divide the power MOSFET into A, B two parts and by sensing the load current to control these two parts. We also increase the switching frequency to reduce the size of inductors and capacitors in regulator circuit, so that the overall area of regulator is reduced and more applicable in portable products. 　　This chip is implemented with TSMC 0.35um Mixed-Signal 2P4M Polycide 5V process provided by National Chip Implementation Center. The input voltage range of this regulator is 3.3V~4.2V and the two outputs are regulated at 1.8V and 2.5V. The regulator operates at switching frequency of 10MHz, the inductor is 0.6uH, and the capacitor is 6.6uF. The voltage ripples of two outputs are 9.27mV and 8.97mV, respectively. The maximum conversion efficiency is 83.7%, and the area of the chip is 2.169×2.049 mm2.