A 125MHz-BW 71.9dB-SNDR VCO-Based CT ΔΣ ADC with Segmented Phase-Domain ELD Compensation in 16nm CMOS

📋 论文概要

该论文提出了一种基于VCO的连续时间ΔΣ调制器，采用分段相位域过剩环路延迟补偿（ELD补偿）技术，解决了传统直接注入补偿导致的过范围问题。在16nm CMOS工艺下实现了125MHz带宽和71.9dB SNDR的性能。

💡 主要创新点

• 提出分段相位域ELD补偿方法，避免直接注入补偿引起的量化电平翻倍或过范围问题
• 采用VCO作为积分器实现相位域处理，降低额外功耗和相位偏移

🏷 关键词

📄 原文摘要

MediaTek, Woburn, MA High-BW continuous-time ΔΣ modulators (CTDSMs), which directly inject excess loop delay compensation (ELDC) at the quantizer input, suffer from the over-range issue due to the 1+αz-1 transfer function of the local feedback loop, where α is the zero-order path coefficient [1-2]. For example, the swing or number of quantization levels will be doubled if α=1 is chosen. On the other hand, injecting the compensation current at the input of the last integrator requires an additional DAC and extra power to minimize excess phase shift [3]. The phase-feedback VCO-based integrating quantizer (VCOIQ) in [4] suggests a unique feature to compensate ELD in the phase domain. In this work, the VCO outputs are rotated directly in the digital domain to implement phase-domain ELDC (PD-ELDC) [5] without overloading any previous stages. Though VCOIQ is essentially a timedomain flash quantizer with a potentially higher number of quantization levels

👥 作者与机构

Sheng-Jui Huang, Nathan Egan, Divya Kesharwani, Frank Opteynde, Michael Ashburn