A 0.6V 13b 20MS/s Two-Step TDC-Assisted SAR ADC with PVT Tracking and Speed-Enhanced Techniques

📋 论文概要

该论文提出了一种0.6V供电的13位20MS/s两步TDC辅助SAR ADC，通过将残差电压量化从电压域转换到时间域，解决了低压下头空间不足的问题。同时引入了PVT跟踪和速度增强技术，提升了电路鲁棒性和转换速度。

💡 主要创新点

• 采用两步TDC辅助结构，利用电压-时间转换器（VTC）和TDC作为后端量化残差电压，避免了传统电压域残差放大在低压下的头空间限制。
• 引入PVT跟踪技术，使ADC能自适应工艺、电压和温度变化，保持性能稳定。
• 通过速度增强技术（如优化比较器或VTC时序）提高转换速率，实现20MS/s采样率。

🏷 关键词

📄 原文摘要

Instituto Superior Tecnico/University of Lisboa, Lisbon, Portugal 1 2 The two-step SAR ADC is an energy-efficient architecture for high-resolution applications, which faces headroom challenges from the voltage-domain residue amplification under a low power supply. A TDC-assisted SAR ADC [1] uses a voltage-to-time converter (VTC) and a TDC as the back-end to quantize the residue voltage of the SAR ADC, which is attractive to the low power supply scenarios by moving the voltage domain quantization of a two-step SAR ADC into the time domain. However, the TDC-assisted SAR ADC encounters several design challenges. For example, it is sensitive to PVT variations due to partial timedomain operation, and its conversion speed is limited significantly by the long VTC latency when there is a small residue input voltage. This paper presents both PVT tracking and speed enhancement techniques for a 13b two-step TDC-assisted

👥 作者与机构

Minglei Zhang1, Chi-Hang Chan1, Yan Zhu1, Rui P. Martins1,2

University of Macau, Macau, China