A 12b 50MS/s Fully Differential Zero-Crossing-Based ADC Without CMFB

📋 论文概要

本文提出一种12位50MS/s的全差分零交叉电路（ZCBC）流水线ADC，无需共模反馈（CMFB）。该设计通过用电流源和零交叉检测器替代传统运放，解决了CMOS工艺缩放中增益和输出摆幅下降的挑战。

💡 主要创新点

• 提出全差分零交叉电路架构，无需共模反馈，简化了设计并提高了鲁棒性。
• 利用电流源和零交叉检测器替代运放，改变了系统动态特性，适应先进CMOS工艺的低增益和低电源电压。

🏷 关键词

📄 原文摘要

As intrinsic device gain and power supply voltages decrease with CMOS technology scaling, it is becoming increasingly challenging for designers of conventional opamp-based switched-capacitor circuits to meet gain and output swing targets, and to ensure stability. Zero-crossing based circuits (ZCBC) are presented in [1-3] as an alternative architecture where each opamp is replaced with a current source and a zero-crossing detector. This changes the dynamics of the system while preserving the functionality. To further improve the robustness of ZCBC designs, we present a 50MS/s, 12b ZCBC pipelined ADC with fully differential signaling and automatic offset compensation. A simplified schematic and timing diagram of 2 adjacent fully differential ZCBC pipeline stages are shown in Fig. 9.3.1 and Fig. 9.3.2, respectively. During the sampling phase, the input voltage is sampled onto sampling capacitors C1±

👥 作者与机构

Lane Brooks, Hae-Seung Lee

Massachusetts Institute of Technology, Cambridge, MA