一种用于高压开关电源的高精度电流采样电路  

A High Precision Current Sensing Circuit in High Voltage Switching Supply

作　　者：王康乐 罗萍[1] 邱双杰 刘泽浪 黄龙[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2018年第1期23-27,共5页Microelectronics

基　　金：国家自然科学基金NSAF联合基金资助项目(U1630117)

摘　　要：设计了一种用于高压Boost电路的电流采样电路。利用SenseFET采样原理,设计了高增益、大带宽的源极输入共源共栅运放,保证了采样电路的高采样精度和快响应速度。设计了延时单元,只在功率管开启时起作用,在功率管关断时无效,保证采样结构在功率管开启时不偏离工作点,并能消除此时的采样输出电流尖峰。在0.35μm 40V BCD工艺下对电路进行仿真验证。结果显示,该采样电路的采样精度可达到99.64%,且采样电流尖峰明显降低。A current sensing circuit for high voltage boost converter was presented.The SenseFET sensing technology was used,and a high gain large bandwidth cascade op amp with source inputs was designed to ensure high sensing accuracy and fast response speed of the sensing circuits.A delay circuit was designed,which could be enabled when the power MOSFET turned on and be disabled when the power MOSFET shut off.When the power MOSFET was turning on,the sensing circuit was not apart from the operation point,so the spike of sensing output current was eliminated.The sensing circuit was simulated in a 0.35μm 40 VBCD process.Results showed that the sensing accuracy could reach 99.64%,and the spike of sensing current was evidently reduced.

关 键 词：峰值电流模 电流采样 高精度 

分 类 号：TN433[电子电信—微电子学与固体电子学]