A low-noise 64-channel front-end readout ASIC for CdZnTe detectors aimed to hard X-ray imaging systems

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• 作者：B. Gan ; T. Wei ; W. Gao ; ^{gaowu@nwpu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; H. Liu ; Y. Hu
• 关键词：CdZnTe detector ; Low-noise ; Front-end readout electronics ; Multi-channels ; ASIC ; Hard X-ray
• 刊名：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 出版年：2016
• 出版时间：21 April 2016
• 年：2016
• 卷：816
• 期：Complete
• 页码：53-61
• 全文大小：1852 K

文摘

In this paper, we report on the recent development of a 64-channel low-noise front-end readout ASIC for CdZnTe detectors aimed to hard X-ray imaging systems. The readout channel is comprised of a charge sensitive amplifier, a leakage current compensation circuit, a CR-RC shaper, two S–K filters, an inverse proportional amplifier, a peak-detect-and-hold circuit, a discriminator and trigger logic, a time sequence control circuit and a driving buffer. The readout ASIC is implemented in TSMC 0.35 μm mixed-signal CMOS technology, the die size of the prototype chip is 2.7 mm×8.0 mm. The overall gain of the readout channel is 200 mV/fC, the power consumption is less than 8 mW/channel, the linearity error is less than 1%, the inconsistency among the channels is less than 2.86%, and the equivalent noise charge of a typical channel is 66 e⁻ at zero farad plus 14 e⁻ per picofarad. By connecting this readout ASIC to an 8×8 pixel CdZnTe detector, we obtained an energy spectrum, the energy resolution of which is 4.5% at the 59.5 keV line of ²⁴¹Am source.