A 0.1-to-0.2V Transformer-Based Switched-Mode Folded DCO in 22nm FDSOI with Active Step-Down Impedance Achieving 197dBc/Hz Peak FoM and 40MHz/V Frequency Pushing

📋 论文概要

本文提出了一种基于变压器的开关模式折叠DCO，可在0.1-0.2V超低电压下工作，通过主动降压阻抗技术显著改善相位噪声和FoM，在22nm FDSOI工艺中实现了197dBc/Hz的峰值FoM。

💡 主要创新点

• 采用三线圈变压器结构实现被动电压增益和降低漏极阻抗，使振荡器能在低于100mV的电源电压下工作。
• 提出主动降压阻抗技术，进一步优化相位噪声性能，在150mV电源下达到197dBc/Hz的FoM。
• 将开关模式折叠DCO应用于4.15-4.97GHz频段，实现超低电压下的高效频率生成。

🏷 关键词

📄 原文摘要

The continuous improvement in ultra-low-power/voltage (ULP/V) circuits paves the way for new near-battery-free IoE applications. In this work, we propose an LC oscillator that can significantly improve phase-noise (PN) performance and the figure of merit (FoM) at ULV supply levels. The structure is applied to a 4.15to-4.97GHz switched-mode DCO that operates from a less-than-100mV supply and achieves a peak FoM of 197dBc/Hz at a 150mV supply. A trifilar-coil oscillator [1] can operate from an ULV supply. The structure benefits from reduced drain impedance and passive voltage gain, provided by the source feedback and the Class-F transformer, to achieve low PN and reliable startup at 0.4V. However, at 0.2V, the PN is penalized from the limited loop gain and voltage swing, and an FoM of 188dBc/Hz is achieved. For the same headroom and using N-coupled oscillators, it is possible to decrease the PN by 10log(N) with the same

👥 作者与机构

Omar El-Aassar, Gabriel M. Rebeiz

University of California, San Diego, La Jolla, CA