We introduce a front-end application specific integrated circuit (ASIC) for a wire based Time-Projection-Chamber (TPC) operating in liquid Argon (LAr). The LAr TPC will be used for long baseline neutrino oscillation experiments. The ASIC must provide low-noise readout of the signals induced on the TPC wires, digitization of those signals at 2 MS/s, compression, buffering and multiplexing. A resolution better than 1000 rms electrons at 200 pF input capacitance for an input range of 300 fC is required, along with low power and operation in LAr (at 87 K). We present the characterization of a commercial technology for operation in cryogenic environment and the first experimental results on the analog front-end. The results demonstrate that CMOS transistors have lower noise and much improved dc characteristics at LAr temperature. Finally, we introduce the concept of “1/f equivalent” to model the low-frequency component of the noise spectral density, for use in the input MOSFET optimization.
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机译：我们为在液态氩（LAr）中运行的基于导线的时间投影腔室（TPC）引入了一种前端专用集成电路（ASIC）。 LAr TPC将用于长期基线中微子振荡实验。 ASIC必须提供TPC线上感应出的信号的低噪声读取，以2 MS / s的速度对这些信号进行数字化，压缩，缓冲和多路复用。在300 pC的输入范围内，要求在200 pF的输入电容下具有比1000 rms电子更好的分辨率，以及低功耗和LAr（87 K）条件下的运行。我们介绍了在低温环境下运行的商业技术的特性，以及在模拟前端上的第一个实验结果。结果表明，CMOS晶体管在LAr温度下具有更低的噪声和更大的直流特性。最后，我们引入“ 1 / f等效”的概念来建模噪声频谱密度的低频分量，以用于输入MOSFET优化。
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