Research And Design Of Current-Mode DC-DC Converter

With the fast growing of portable and battery-operated electronic systems, electronic products request the power supply to be much better. In this thesis,I design a power managment IC for mobile,MP3,and PDA etc. Its lowest operation voltage is 2.4V and highest 5.0V. Besides its typical operation voltage is 3.7V.Which are decided by Lithium-battery.And the output voltage is 1.2V,which is decided by 0.13um process. Accordingly,I will complete the design with current-mode buck converter.On the basis of above, I do some work as below: Do research on the market and technique of power management Ices; Do analyze the circuit module of the buck converter.; Do research on the factor which affect the efficiency and provide a method for optimizing the Power Mos;Do design on circuit, in which more on-chip technique is used to decrease the element number and reduce the chip's size and cost; Do experiment for validating the function. The chip is fabricated with SMIC 0.13um 3.3V CMOS process and the test was done with PCB board. In the proposed buck converter, the operation voltage is from 2.4V to 5.0V, the loading current is from 0.1A to 0.6A, the switching frequency is at 700 KHz and the efficiency is above 90%.But limited by time and my experience,there are still some insufficiency. Such as, reduce the quiescent current and combine PFM mode with PWM mode to improve the efficiency.Also the protect function must be enhanced in the next work.