A 65nm CMOS CT ΔΣ Modulator with 81dB DR and 8MHz BW Auto-Tuned by Pulse Injection

📋 论文概要

该论文提出了一种基于脉冲注入的自动调谐技术，用于补偿连续时间ΔΣ调制器中RC和C/Gm工艺角变化导致的滤波时间常数不准确问题。采用65nm CMOS工艺实现了一个81dB动态范围、8MHz带宽的连续时间ΔΣ调制器。

💡 主要创新点

• 提出利用脉冲注入进行自动调谐，无需额外校准电路，有效补偿工艺变化对RC和C/Gm的影响。
• 在65nm CMOS低功耗工艺中实现了高达81dB DR和8MHz BW的连续时间ΔΣ调制器，适合无线SoC应用。

🏷 关键词

📄 原文摘要

University of California, San Diego, CA Conexant, Palm Bay, FL 2 In the digital wireless SoC applications, CT ΔΣ ADCs have been widely used for I/Q quantization due to the built-in anti-aliasing function and insensitivity to the input sampling error. They also offer higher-frequency performance than SC modulators as no critical opamp settling is required. CT modulators with low OSR have achieved a DR greater than 75dB in a 20MHz band [1, 2]. However, they all suffer from inaccurate active filtering as filter time constants are set by RC and C/Gm values that vary by as much as ±20 to 30%. By lowering OSR, the signal band can be widened, but the in-band zero of the NTF should be optimally placed to maximize the DR. Inaccurate NTF zero either degrades the DR or makes the modulator unstable. This work presents an exact time-constant auto-tuning method using an LMS algorithm. With a binary pulse dither injected into the loop at the input of the

👥 作者与机构

Yun-Shiang Shu1, Bang-Sup Song1, Kantilal Bacrania2, 1