2025年"核理安邦“联合博士生学术论坛

Fast front-end readout design for NICA-MPD shashlik electromagnetic calorimeter

Not scheduled

1h

Location: 清华大学核能与新能源技术研究院

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Speaker

冉 鑫驰 (清华大学工程物理系)

Abstract

Silicon photomultipliers (SiPMs) are highly valued for their excellent light response and high gain characteristics, yet their application in fast timing scenarios is often limited by their high terminal capacitance, typically over 300 pF. In electromagnetic calorimeters, sub-nanosecond time measurements allow these detectors to function as supplementary time-of-flight devices, specifically aiming for a time resolution of 150 ps in the NICA-MPD. To address these challenges, this study proposes a novel front-end readout electronics design featuring a two-stage common-base transimpedance preamplifier and a 12-bit 200 MS/s pipelined successive-approximation-register (SAR) analog-to-digital converter (ADC). Extensive SPICE simulations, using the Hamamatsu S13360-6025 as the input source, demonstrate the preamplifier's rapid rise time and good linearity. Experimental results from laser testing confirm that this fast preamplifier design achieves a remarkable time resolution of better than 20 ps. The ADC circuit, designed using the TSMC65nmLP process, employs a two-stage pipelined SAR structure with a two-step conversion technique (6-bit + 7-bit), incorporating redundancy in the second step. Testing at a 160MHz sampling rate with an 80MHz input condition showed that, at Vpk = -1dBFS, the ADC's FFT spectrum analysis yielded an effective number of bits (ENOB) of 9.34 and a spurious-free dynamic range (SFDR) of 73.8 dBc. Preliminary System-level timing assessments under a 200 MHz sampling rate revealed that waveforms with 3 to 4 sampling points on the rising edge, with a rise time of 15 to 20 ns, achieved a time resolution of approximately 20 ps.

摘要

​硅光电倍增器（SiPMs）因其出色的光响应和高增益特性而备受青睐，但其在快速定时应用中的使用常受到其高端接电容（通常超过300 pF）的限制。​在电磁量热器中，亚纳秒级的时间测量使这些探测器能够作为辅助的飞行时间设备使用，特别是在NICA-MPD实验中，目标时间分辨率为150皮秒。​

为应对这些挑战，本研究提出了一种新颖的前端读出电子学设计，采用两级共基极跨阻前置放大器和一个12位、200 MS/s的流水线逐次逼近寄存器（SAR）模数转换器（ADC）。​利用Hamamatsu S13360-6025作为输入源进行的大量SPICE仿真显示，该前置放大器具有快速的上升时间和良好的线性度。​激光测试的实验结果证实，该快速前置放大器设计实现了优于20皮秒的卓越时间分辨率。​

ADC电路采用TSMC 65nm低功耗工艺设计，采用两级流水线SAR结构，并引入了两步转换技术（6位+7位），在第二步中包含冗余设计。​在160 MHz采样率和80 MHz输入条件下进行的测试显示，在Vpk = -1dBFS时，ADC的FFT频谱分析得到了9.34的有效位数（ENOB）和73.8 dBc的无杂散动态范围（SFDR）。​

在200 MHz采样率下进行的初步系统级时间评估表明，对于上升时间为15至20纳秒的波形，在上升沿具有3至4个采样点的情况下，时间分辨率约为20皮秒。