提高SoC供电精度的CMOS低压差线性稳压器关键技术研究

Complex SoC systems need multiple power supplies as well as low-noise voltage source. Integration of the whole power management system is helpful to simplify the layout of power network, saving system cost. Low dropout regulator (LDO) is an important research area of power management ICs, where degradation of power supply rejection ability at high frequency and load-transient response restricts the integration process. This project will first focus on the researches of architectures and methodologies of high-performance LDOs. The merits and demerits of corresponding circuits are analyzed in depth. In this way, improvements with maintained original-advantages in new designs can be purposefully made. Secondly, to meet the demand of SoC applications, novel low-power feedforward circuits will be proposed to boost the PSR performance at MHz frequency. For improving transient performance, capacitance coupling with nonlinear control theory, dual loop control and low-voltage design technology will be presented. It will analyze models of the dynamic feedback loop to extend the bandwidth as much as possible. The above-mentioned techniques will not decay other important parameters, such as current efficiency and small-signal system stability. Expected results of this study will introduce important theoretical and realistic significance for improving the accuracy of SoC power supplies and developing fully integrated SoC systems with independent intellectual property rights.

复杂SoC需要多电压和低噪声电源供电，集成整个电源管理系统有利于简化电源网络布局布线，节约系统成本。低压差线性稳压器（LDO）是电源管理集成电路的一个重要研究领域，高频电源抑制能力和负载瞬态响应性能的衰减是其集成化进程中面临的主要问题，期待采取新的技术予以突破。本项目首先对现有LDO架构进行深入研究，分析其优点和存在的不足，从而在新的电路设计中保持原有优势，改进相应缺点。针对SoC应用需求，提出新型低功耗前馈电路架构，实现MHz频率附近PSR性能的大幅提升。基于低功耗的瞬态增强技术，提出电容耦合的非线性控制理论、双环控制理论和低压供电技术，并对负反馈环路动态响应进行频域建模分析，最大程度拓展环路带宽。上述各项技术不会衰减LDO的其它重要性能参数，包括电流效率、系统小信号稳定性等。该项研究的预期成果，对提高SoC供电精度，发展我国具有自主知识产权的全集成SoC系统具有重要的理论和现实意义。

本项目主要针对复杂SoC供电系统中低压差线性稳压器（LDO）面临的主要难题开展深入研究，包括高频电源抑制能力和负载瞬态响应性能的提升两方面。该课题首先对现有LDO架构的优缺点进行对比分析，从而在新的电路设计中保持原有优势，改进相应缺点。针对SoC应用需求，提出新型低功耗前馈电路架构，最大限度拓宽前馈环路带宽，实现MHz频率附近PSR性能的大幅提升。基于低功耗的瞬态增强技术，提出电容耦合的非线性控制理论、信号和瞬态电流倍增技术以及低压供电方案等，并对负反馈环路动态响应进行频域建模分析，最大程度拓展环路带宽。上述各项技术不会衰减LDO的其它重要性能参数，包括电流效率、系统小信号稳定性等。该项研究成果能够广泛应用于不同的半导体制成工艺，实现标准化模块设计和系统集成，对提高SoC供电精度具有重要作用。