Taming the Stability Challenge of Analog and Mixed-Signal Systems: Theory, Analysis and Design

智能优点稳定性是模拟和混合信号集成电路最关键的设计问题之一。失去稳定性会导致性能下降，甚至出现灾难性的故障。在模拟功能块级别，该项目解决了由设计构建或通过版图寄生形成的大量反馈环路的存在带来的重大挑战。将开发新的基于回路的稳定性度量，以填补现有的相位和增益裕度概念以及基于单回路的稳定性分析方法留下的重要空白。将开发出在提取的大型模拟设计中识别不稳定回路的计算高效方法。稳定性挑战的另一个来源是，为了提高性能和容忍变化等目的，集成了越来越复杂的数字控制。然而，包含这些控制将极大地复杂化对设计稳定性的理解，这将通过开发用于严格稳定性分析的控制理论方法和确保稳定性的新电路设计技术来解决。在通过复杂分布负载相互作用的模拟电路网络中也存在显著的稳定性设计挑战。对于如此大的网络，本项目将发展支持本地化稳定性检查和设计保证的理论和方法。为了将本项目中开发的理论和方法应用于实践，我们将研究在保证稳定性的同时将性能降级降至最低的电路级设计技术。这将需要系统的权衡分析，阐明拟议的稳定性指标与其他设计规范之间的相互作用，开发新的补偿/控制方案和电路拓扑，以确保以最小的开销实现稳定性，并开发支持这种新设计实践的设计方法。将吸引本科生和代表性不足群体的学生参与研究。本科生和研究生课程将受益于该项目的预期结果，该项目还将在研究界和行业中传播。这项工作对社会的影响是广泛而重大的。模拟和混合信号电路变得越来越普遍，并在包括片上系统在内的许多系统中使用。随着设计复杂性的增加，模拟和混合信号电路的设计面临着许多挑战。其中之一是稳定。确保设计稳定性和执行稳定性约束设计优化的能力将有助于构建更好和更健壮的电路，还可能创造新的电子市场。最后，有针对性的工作的普遍性可能有助于其他科学和工程学科在稳定性分析和设计方面的进步。

Intellectual MeritStability is one of the most critical design concerns for analog and mixed-signal integrated circuits. Loss of stability would produce performance degradation or even catastrophic failures. At the analog functional block level, this project addresses the significant challenges brought by the existence of large numbers of feedback loops constructed by design or formed through layout parasitics. New loop-based stability metrics will be developed to fill in the important gap left by the existing concepts of phase and gain margins and single-loop based stability analysis methods. Computationally efficient methods for identifying unstable loops in extracted large analog designs will be developed. Another source of stability challenge arrives as increasingly complex digital controls are integrated for purposes such as performance boost and variation tolerance. Inclusion of these controls, however, drastically complicates the understanding of design stability, which will be addressed by developing control-theoretical methods for rigorous stability analysis and new circuit design techniques to ensure stability. Significant stability design challenges also exist in networks of analog circuits that interact with each other through complex distributed loads. For such large networks, this project will develop theory and methods that support localized stability checking and design assurance. To bring the theory and methods developed in this project to practice, circuit-level design techniques that provide guaranteed stability with minimum performance degradation will be investigated. This will entail systematic tradeoff analysis that sheds light on the interactions between the proposed stability metrics and other design specifications, development of novel compensation/control schemes and circuit topologies that ensure stability with minimum overhead, and development of design methodologies that support this new design practice.Broader ImpactsThe focused theoretical investigation and engineering research of this project will provide excellent educational opportunities to students. Research participation from undergraduate students and students from underrepresented groups will be attracted. Undergraduate and graduate curriculum will be benefited from the expected results of this project, which will also be disseminated in the research community and industry. The impact of this work to society is broad and significant. Analog and mixed-signal circuits become increasingly ubiquitous and are employed in many systems including systems-on-chips. The design of analog and mixed-signal circuits is confronted by many challenges as design complexity grows. One of them is stability. The ability in ensuring design stability and performing stability-constrained design optimization will help build better and more robust circuits and may also create new markets of electronics. Finally, the generality of the targeted work is likely to contribute to the advancements in stability analysis and design in other science and engineering disciplines.