摘要： 提出一种有效提升大电流输出应用的低压差线性稳压器（LDO）环路稳定性的技术，采用负载追踪补偿方式消除电路输出端与负载相关的极点对环路稳定性的影响，且在维持环路低频增益不变的前提下降低高频下环路中节点阻抗，从而达到同时提升输出精度和优化瞬态响应性能的目的。采用TSMC 0.18 µm BCD工艺进行仿真验证，结果表明电路最大输出电流6 A，在6 A/6 μs的负载突变情况下输出电压下冲为36.6 mV，过冲为35.3 mV，稳定时间小于56.3 μs。全负载电流范围内，瞬态性能大幅提升。

中图分类号：TN432 文献标志码：A DOI: 10.16157/j.issn.0258-7998.234217
中文引用格式： 朱琪，黄登华. 基于负载追踪补偿的大电流LDO设计[J]. 电子技术应用，2024，50(3)：26-30.
英文引用格式： Zhu Qi，Huang Denghua. Design of a high current LDO based on load tracking technology[J]. Application of Electronic Technique，2024，50(3)：26-30.

Design of a high current LDO based on load tracking technology

Abstract： This paper presents an effective load tracking compensation scheme to improve the loop stability of high current low-dropout linear regulator (LDO). By the proposed technique, the influence of variable load on the loop stability is eliminated, besides the low frequency loop gain retains to high while the high frequency impedance is greatly attenuated, finally both high output precision and decent transient response performance is achieved simultaneously. Simulated by TSMC 0.18 µm BCD process, the results show that the circuit is capable of delivering load current up to 6 A. For a load step of 6 A/6 μs, the circuit has a maximum undershoot of 36.6 mV and a maximum overshoot of 35.3 mV, the stable time is less than 56.3 μs. The transient performance is greatly improved within the full load current range.

Key words : low-dropout linear regulator；load tracking；loop gain；transient response