A Fully Dynamic Low-Power Wideband Time-Interleaved Noise-Shaping SAR ADC
A Fully Dynamic Low-Power Wideband Time-Interleaved Noise-Shaping SAR ADC
复制标题
全动态低功耗宽带时间交错噪声整形 SAR ADC
DOI：
10.1109/jssc.2021.3072034
复制
发表时间：
2021
影响因子：
5.4
通讯作者：
Nan Sun
中科院分区：
文献类型：
--
作者：
Haoyu Zhuang;Jiaxin Liu;He Tang;Xizhu Peng;Nan Sun
本文提出了一种基于前馈积分器级联 (CIFF) 架构的全动态、低功耗、宽带、时间交错 (TI)、噪声整形 (NS) 逐次逼近寄存器 (SAR) 模数转换器 (ADC)。交错操作和环路滤波器都是通过使用全无源开关电容器电路来实现的。前馈求和由多路动态比较器实现。整体噪声传递函数 (NTF) 对于工艺、电压和温度 (PVT) 变化具有高度鲁棒性，因为 NTF 由器件比率决定。这使得NTF零点接近1，具有良好的NS效果。与最近发布的基于误差反馈（EF）架构的TI NS SAR相比，这项工作不需要静态放大器，从而实现完全动态操作。同时，它消除了NTF对PVT敏感放大器增益的依赖。该原型 ADC 采用 40 nm CMOS 工艺实现，在 1.1 V 电源下实现了 69.1 dB 的 SNDR、50 MHz 的带宽和 8.5 mW 的功耗，从而实现了 36.3 fJ/转换步的 Walden FoM。
This article proposes a fully dynamic, low-power, wideband, time-interleaved (TI), noise-shaping (NS) successive-approximation-register (SAR) analog-to-digital converter (ADC) based on the cascade of integrators with feedforward (CIFF) architecture. Both the interleaving operation and the loop filter are implemented by using the fully passive switched-capacitor circuits. The feedforward summation is realized by a multi-path dynamic comparator. The overall noise transfer function (NTF) is highly robust against process, voltage, and temperature (PVT) variations since the NTF is determined by device ratios. This allows the NTF zeros to be close to 1, with a good NS effect. Compared with a recently published TI NS SAR based on the error-feedback (EF) architecture, this work does not need a static amplifier, thus leading to the fully dynamic operation. Meanwhile, it eliminates the dependence of NTF on the PVT-sensitive amplifier gain. Implemented in a 40-nm CMOS process, the prototype ADC achieves an SNDR of 69.1 dB, a bandwidth of 50 MHz, and a power consumption of 8.5 mW under a 1.1-V supply, leading to a Walden FoM of 36.3 fJ/conv.-step.