The Design Of The High-Side Current-Sensing In Buck DC-DC Converter

With the rapid development of the electronics and the increasing demand for consumer electronic, the efficiency of the battery has become a focus, and the high efficiency's dc to dc converters become to the power management's topic too. The current mode control has many advantages than the voltage mode such as better stability and faster dynamic response and so on. So the current-sensing is an important part in the dc to dc converters.In this paper, we research the current mode control dc to dc converters design, the current-sensing methods and the choices of current-sensing to the dc to dc system's needs, combines the advantages of several detection methods, design a new method, and get good results, this is the first job of this paper. Then on the choices of the design circuits, because of the wide ranges of the input voltage, design the circuit to fit the system's needs, make the accuracy to the 97%, this is the second job of this paper. Behind it we research the error in the current loop, and analysis the causes of the error, this is the third job of this paper. Finally, in the 0.6um 30v BCD process, we simulate the circuit with the hspice software, and do a compare with the IEEE's circuits, this is the forth job of this paper.In the beginning of this paper we introduce the importance of the power ICs and the development. Then we describe the traditional current mode DC-DC power management IC control—current mode and voltage mode, and introduces several traditional current-sensing methods, with an analysis of their advantages and disadvantages. Then give the methods of this paper and the circuit design's background, followed it we show the current-sensing amplifier and current-sensing circuit design. Behind it, we give the current-sensing circuit's simulation results based on a high-voltage buck dc to dc power converters system. Finally we sum up this work.