Large-Area, Fast-Gated Digital SiPM With Integrated TDC for Portable and Wearable Time-Domain NIRS
Large-Area, Fast-Gated Digital SiPM With Integrated TDC for Portable and Wearable Time-Domain NIRS
复制标题
具有集成 TDC 的大面积、快速门控数字 SiPM，适用于便携式和可穿戴时域 NIRS
DOI：
--
复制
发表时间：
2020
影响因子：
5.4
通讯作者：
A. Tosi
中科院分区：
文献类型：
--
作者：
E. Conca;V. Sesta;M. Buttafava;F. Villa;L. D. Sieno;A. D. Mora;D. Contini;P. Taroni;A. Torricelli;A. Pifferi;F. Zappa;A. Tosi
我们介绍了大面积、快速门控、全数字单光子探测器的设计和表征，该探测器具有可编程活动区域、内门发生器和带有内置直方图生成器电路的时间数字转换器 (TDC)，适合与脉冲激光源耦合时执行高灵敏度时域近红外光谱 (TD-NIRS) 测量。我们使用了一种新颖的低功耗差分传感技术来优化面积占用。该光电探测器是一款时间选通数字硅光电倍增管 (dSiPM)，具有 8.6 mm2 光敏面积、37% 填充因子和 ~300 ps (20%–80%) 栅极上升沿，基于低噪声单光子雪崩二极管 (SPAD)，采用 0.35-$mu ext{m}$ CMOS 技术制造。带有直方图生成器的内置 TDC 具有 78 ps 的最低有效位 (LSB) 和 128 个时间段，并且该集成电路可以直接与带有串行接口的低成本微控制器连接，用于编程和读出。实验表征表明，时间响应高达 300 ps 半高全宽 (FWHM)，动态范围 >100 dB（得益于可编程活动区域大小）。该微电子探测器为小型化、独立、多波长 TD-NIRS 系统铺平了道路，该系统具有前所未有的集成度和响应度，适用于便携式和可穿戴系统。
We present the design and characterization of a large-area, fast-gated, all-digital single-photon detector with programmable active area, internal gate generator, and time-to-digital converter (TDC) with a built-in histogram builder circuit, suitable for performing high-sensitivity time-domain near-infrared spectroscopy (TD-NIRS) measurements when coupled with pulsed laser sources. We used a novel low-power differential sensing technique that optimizes area occupation. The photodetector is a time-gated digital silicon photomultiplier (dSiPM) with an 8.6-mm2 photosensitive area, 37% fill-factor, and ~300 ps (20%–80%) gate rising edge, based on low-noise single-photon avalanche diodes (SPADs) and fabricated in 0.35- $mu ext{m}$ CMOS technology. The built-in TDC with a histogram builder has a least-significant-bit (LSB) of 78 ps and 128 time-bins, and the integrated circuit can be interfaced directly with a low-cost microcontroller with a serial interface for programming and readout. Experimental characterization demonstrated a temporal response as good as 300-ps full-width at half-maximum (FWHM) and a dynamic range >100 dB (thanks to the programmable active area size). This microelectronic detector paves the way for a miniaturized, stand-alone, multi-wavelength TD-NIRS system with an unprecedented level of integration and responsivity, suitable for portable and wearable systems.