低压差线性稳压器噪声测试研究  

Research on Noise Measurement of Low Dropout Linear Regulator

作　　者：林卓逸 王小强[1] 吴朝晖[2] 李斌[2] 罗军[1] 余永涛 LIN Zhuoyi;WANG Xiaoqiang;WU Zhaohui;LI Bin;LUO Jun;YU Yongtao(The Fifth Electronics Research Institute of Ministry of Industry and Information Technology,Guangzhou Guangdong 510610,China;School of Electronic and Information Engineering,South China University of Technology,Guangzhou Guangdong 510641,China)

机构地区：[1]工业和信息化部电子第五研究所,广东广州510610 [2]华南理工大学电信与信息学院,广东广州510641

出　　处：《电子器件》2023年第5期1199-1203,共5页Chinese Journal of Electron Devices

基　　金：广东省重点领域研发计划项目(2020B0404030005)。

摘　　要：输出负载、输出电容是影响低压差线性稳压器输出噪声特性的重要因素,但国内外缺乏系统性研究。在宽范围的输出负载和输出电容的条件下,开展了正电压输出的LDO噪声测试和分析。结果表明,稳压器件输出噪声电压功率谱密度曲线表现出先减小然后增大,并在达到拐点峰值后快速减小,最后基本不变的特征。不同的输出负载、输出电容条件下,LDO的输出噪声存在显著差异。随着输出电流的增大或输出电容减小,输出噪声电压功率谱密度曲线拐点右移,频率增加,输出噪声电压增大。输出负载、输出电容与LDO输出噪声的相关性在于输出电阻或输出电容的改变,会直接影响影响LDO环路的主极点频率,进而影响环路增益和带宽,最终导致器件输出噪声的变化。The output load and output capacitance are important factors that affect the output noise characteristics of the low dropout linear regulator,but there is a lack of systematic research at home and abroad.The noise test and analysis of a positive voltage output LDO is carried out under the conditions of a wide range of output loads and output capacitors.The results show that the power spectral density curve of the output noise voltage of the voltage regulator device first decreases and then increases,decreases again rapidly after reaching the peak value of the inflection point,and finally remains basically unchanged.There are significant differences in the output noise of LDOs under different output load and output capacitance conditions.As the output current increases or the output capacitance decreases,the inflection point of the output noise voltage power spectral density curve shifts to the right,the frequency increases,and the output noise voltage increases.The correlation between output load,output capacitance and LDO output noise lies in that the change of output resistance or output capacitance will direct affect the dominant pole frequency of the LDO loop,which in turn affects the loop gain and bandwidth,and ultimately leads to changes in the output noise of the device.

关 键 词：低压差线性稳压器 噪声测试 输出负载 输出电容 传输函数 

分 类 号：TN407[电子电信—微电子学与固体电子学]