【作者】 戴军； 王海时； 叶星宁；

【Author】 Dai Jun Wang Haishi Ye Xingning (Key Laboratory of Electronic Thin Film and Integrated Devices, UESTC Chengdu 610054)

【机构】 电子科技大学电子薄膜与集成器件国家重点实验室；

【摘要】 本文分析了电流检测电路在电流模式控制开关电源中的重要性,对几种常用的电流检测电路进行分析,指出其优点和不足。在此基础上设计了一款新颖的电流检测电路,并且利用台联电0．6μm BCD工艺进行仿真验证。该电路通过直接检测功率管上的压降检测功率管上流过的电流,额外损耗为零,不影响芯片效率。消除了功率管导通电阻受非线性和温度的影响而产生的检测误差,检测精度高。本电路可低压应用,适合现代集成电路工艺。更多还原

【Abstract】 This paper analyzes the importance of current sensing circuit in current control switching power supply and carries on the analysis to several kinds of commonly used current sensing circuits, points out their advantages and disadvantages. Then a novel current sensing circuit is designed, verified with simulation by 0.6μm BCD process of UMC. By sensing the current of the power MOSFET by detecting the voltage drop of the power MOSFET, the extra loss of this circuit is zero, without affects to the chip efficiency. It eliminates the detection error which produced by the non-linearity of the power MOSFET’s on-state resistance and the temperature influence, which insures high detection precision. This circuit facilitates low-voltage operation and suits the modern IC processes.更多还原