Abstract: A 32-channel CMOS charge readout ASIC, which amplifies the weak signal generated by the X-ray detector array, is designed. Each channel contains a charge sensitive amplifier, a correlated double sampler, and a sample-and-hold circuit. Noise characteristic of the readout circuit, especially the CSA, is theoretically analyzed, based on which optimization of schematic is achieved. Simulation results show that the integrated output noise is 69.7 μV.

Key words: X-ray detector, low noise, charge readout ASIC

摘要： 设计一种32通道X射线探测器读出电路, 将探测到的微弱电信号进行放大并转换成电压信号读出。该电路中每个通道包含一个电荷灵敏放大器、一个相关双采样电路和一个采样保持电路。 为提高成像质量, 对读出电路进行低噪声设计, 其中前级的噪声贡献尤为明显, 因此重点对噪声源进行理论分析并采取相应的降噪措施。仿真得到输出积分噪声为69.7 μV。

关键词: X射线探测器, 低噪声, 读出电路