CZT探测器低噪声读出电路设计

Design of a Low-Noise Readout Circuit for CZT Detector

采用TSMC 0.35μm CMOS工艺,设计了CZT探测器低噪声读出电路链和一款多通道能量读出ASIC,该电路将应用于8×8CZT像素探测器的能量读出。给出了系统框图及低噪声能量读出电路链,分析了低噪声技术策略。实验结果表明,能量分辨范围为20keV～4MeV,等效噪声电荷(ENC)小于150个电子,电荷转电压增益为9.2V/pC,非线性度小于3%,多通道串扰小于10个电子,满足设计需求。

A low-noise front-end readout circuit chain and a multi-channel energy readout ASIC for CZT detector in PET imaging system were designed based on TSMC＇s 0.35 μm mixed-signal CMOS process.Architecture of the PET imaging system and the low-noise energy readout circuit chain were presented,and low-noise technology strategy was analyzed.Simulation results showed that the energy resolution was from 20 keV to 4 MeV,the equivalent noise charge（ENC） was less than 150 electrons（rms）,the charge-to-voltage gain was 9.2 V/ pC,the non-linearity was below 3%,and crosstalk of multi channels was less than 10 electrons,satisfying requirements of the design.