一种用于低噪声LDO的动态零点补偿技术  

A zero-pole compensation technique used in low noise LDO

作　　者：吴嘉祺 姚思远[1,2] 刘智 陈泽强[1,2] 魏巍 于洪波 WU Jiaqi;YAO Siyuan;LIU Zhi;CHEN Zeqiang;WEI Wei;YU Hongbo(Xi'an Microelectronics Technology Institute,Xi'an 710054,China;Laboratory of Science and Technology on Radation-Harden Integrated Circuits,China Aerospace Science and Technology Corporation,Xi'an 710054,China)

机构地区：[1]西安微电子技术研究所,陕西西安710054 [2]中国航天科技集团有限公司抗辐射集成电路技术实验室,陕西西安710054

出　　处：《微电子学与计算机》2024年第1期142-150,共9页Microelectronics & Computer

摘　　要：为提高低压差线性稳压器(Low-DropOut Linear Regulator,LDO)的稳定性并降低前馈电路所产生的噪声,提出了一种生成自适应补偿零点的低噪声前馈电路。该前馈电路通过镜像调整管的负载电流,通过低值反馈电阻形成高增益反馈信号,与LDO输出电压经反馈网络传递给反馈端的信号耦合形成由负载电容、负载电流控制的可控零点,可有效提高LDO电路整体的稳定性。此外,电路内部加入了产生动态极点的自适应电流补偿电路以保证次极点不会对环路的相位裕度产生影响。基于0.18μm BCD工艺设计,该电路在0~800 mA的宽负载范围、5 V输入3.3 V输出下相位裕度均高于48°,适用负载电容范围≥1μF,同时该LDO在10~100 kHz的频率范围内输出噪声仅为5.0617μVrms。In order to improve the stability of Low-Drop Out Linear Regulator(LDO)and reduce the noise generated by the feed-forward circuit,a low-noise feed-forward circuit that generates an adaptive compensation zero point is proposed.The feed-forward circuit forms a high-gain feedback signal through the low-value feedback resistor through the load current of the mirror pass transistor,and couples with the LDO output voltage to the signal transmitted to the feedback end through the feedback network to form a controllable zero point controlled by the load capacitance and load current,which can effectively improve the overall stability of the LDO circuit.In addition,an adaptive current compensation circuit that generates dynamic poles is added to ensure that the secondary poles do not affect the phase margin of the loop.Based on the 0.18μm BCD process,the phase margin of the circuit is higher than 48°under a wide load range of 0 mA to 800 mA and a 5 V input 3.3 V output,and the applicable load capacitance range is≥1μF.At the same time,the output noise of the LDO is only 5.0617μVrms in the frequency range of 10 kHz to 100 kHz.

关 键 词：低压差线性稳压器(LDO) 前馈电路 自适应补偿 低噪声 频率补偿 稳定性 

分 类 号：TN432[电子电信—微电子学与固体电子学]