A Compact Fully Dynamic Capacitance-to-Digital Converter With Energy-Efficient Charge Reuse
A Compact Fully Dynamic Capacitance-to-Digital Converter With Energy-Efficient Charge Reuse
复制标题
具有节能电荷重用功能的紧凑型全动态电容数字转换器
DOI：
10.1109/lssc.2020.3036223
复制
发表时间：
2020
影响因子：
2.7
通讯作者：
P. Harpe
中科院分区：
文献类型：
--
作者：
Haoming Xin;Kevin Pelzers;P. Baltus;E. Cantatore;P. Harpe
提出了一种利用新型电荷复用技术的超低功耗全动态电容-数字转换器（CDC）。CDC包括作为传感前端的电容桥和用于信号数字化的异步逐次逼近寄存器ADC。前端和ADC之间的被动电荷共享用于实现完全动态的操作。与每次测量重置电容桥（具有大型传感和参考电容器）不同，电荷在多次测量中保持并重复使用以节省能源。采用功率门控技术降低待机功率。因此，CDC的优点值低至4.3 fJ/ convv -step，即<inline-formula> < text -math notation="LaTeX">$> 3\times $ </ text -math></inline-formula>，优于目前的技术水平。此外，它支持功率与速度的固有缩放，最小功率仅为44 pW，芯片面积<inline-formula> < text -math notation="LaTeX">$6440~\mu \text{m}^{2}$ </ text -math></inline-formula>。
An ultra-low-power fully dynamic capacitance-to-digital converter (CDC) that exploits a novel charge reuse technique is proposed. The CDC includes a capacitive bridge as the sensing frontend and an asynchronous successive approximation register ADC for signal digitization. Passive charge sharing between the frontend and ADC is used to enable a fully dynamic operation. Instead of resetting the capacitive bridge (with large sensing and reference capacitors) for each measurement, the charge is maintained and reused over many measurements to save energy. A power-gating technique is employed to reduce the stand-by power. As a result, a figure of merit as low as 4.3 fJ/conv-step is achieved for the CDC, which is <inline-formula> <tex-math notation="LaTeX">$> 3\times $ </tex-math></inline-formula> better than the state of the art. Furthermore, it supports an inherent scaling of power versus speed with a minimum power of only 44 pW and a compact chip area of <inline-formula> <tex-math notation="LaTeX">$6440~\mu \text{m}^{2}$ </tex-math></inline-formula>.