| In today's electronic products world, power management becomes an essential circuit system. The development tendency of electronic product s is integration and miniaturization, which calls for power management chips smaller and smaller. Increasing the switching frequency of power management chip can meet this requirement, but the efficiency will be reduced accordingly. The purpose of this paper is increasing the switching frequency to realize integration and miniaturization, but the efficiency of power management chips is also at a higher level.First, this paper gives modeling of Buck DC-DC converter and analysis of the major power dissipation. The modeling of Buck DC-DC converter is to keep the converter stable, and the modeling and the analysis of the power dissipation is to indicate which power dissipation is the main loss in the higher switching frequency converter, and proposed the methods for reducing the power consumption.Secondly, discussing the designs of the Buck DC-DC converter modules, from circuits which is related to the system-level (such as power management controllers, L, C selections) design to the circuits (DCM and other circuits) using to improve the efficiency of the Buck DC-DC converter; From the main circuits (such as compensator etc.) which influence the stability of Buck DC-DC converter to the circuits (over-current protection circuit, et al) which protect the converter work well. At last a high frequency and high efficiency converter is designed and fabricated in Chartered 0.35μm CMOS process.Thirdly, the measured results are given to explain that the proposed methods are applied and realized, and show that the efficiency of the buck DC-DC converter is above 80% over a wide load current range from 8mA to 570mA, and the peak efficiency is 86% at 10 MHz switching frequency. For another Buck DC-DC converter, the peak efficiency is 82% at 20MHz switching frequency.Finally, the whole design work is concluded and some further research directions are given. |
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