基于开关电容的低失调电流采样电路设计  

Design of Low Offset Current Sensing Circuit Based on Switched-Capacitor

作　　者：张景杨 贺威[2] Zhang Jingyang;He Wei(College of Optoelectronic Engineering, Shenzhen University, Guangdong Shenzhen 518060;College of Electronic Science and Technology, Shenzhen University, Guangdong Shenzhen 518060)

机构地区：[1]深圳大学光电工程学院,广东深圳518060 [2]深圳大学电子科学与技术学院,广东深圳518060

出　　处：《科技广场》2017年第12期66-70,共5页Science Mosaic

基　　金：深圳市科技计划项目(编号:JCYJ20140418095735595;编号:JCYJ20140418091413574)

摘　　要：本文介绍了一种基于开关电容的低失调电流采样电路,采用电阻采样技术,通过时钟开关控制开关电容积分器,周期性的将运放的失调电压反馈到主环路进行负反馈调节,从而降低运放的失调电压对输出电压的影响。HSPICE仿真结果表明,该电路能够将输出失调电压降低到总输入失调电压的0.08%以下。该电路已经成功运用在0.36um工艺下的12通道电源管理芯片中,性能可靠。This article presents a low-offset current sensing circuit based on switched capacitor,using resistance sampling techniques. The circuit controls the switched capacitor through the clock switch, and periodically feedbacks the op amp＇s offset voltage to the main loop for negative feedback regulation, thereby reducing the impact of the op amp＇s offset voltage on the output voltage. HSPICE simulation results show that the circuit can reduce the output offset voltage to less than 0.08% of the total input offset voltage. The circuit has been successfully used in a 12-channel power management chip under the 0.36 um process, and the performance is reliable.

关 键 词：开关电容 电流采样电路 负反馈调节 

分 类 号：TN432[电子电信—微电子学与固体电子学]