适用于像素CZT辐射探测器ROIC的高精度S/H电路(英文)

A High Accuracy S/H Circuit for ROIC of Pixel CZT Radiation Detector

为了提高像素CZT辐射探测器读出电路的精度,用Cadence的Spectre工具基于GSMC0.18μm工艺模型模拟仿真,设计了一种适用于像素CZT辐射探测器读出电路的高精度双相采样保持电路。首先,用两个电流脉冲信号源建立了前置放大器的输出信号模型,它包括高频噪声和幅度为0.28mV有用信号。然后,设计了一个用于高精度采样保持电路的高性能运算放大器。经过模拟仿真得到其共模输入范围为0.6～1.4V,直流增益为74～80dB,相位裕度大于60°。最后完成了高精度双相采样保持电路的设计,仿真结果显示它能很好的跟随输入信号的形状并且能在信号幅度达到相对误差为0.35%的采样保持精度。

In order to improve the accuracy of ROIC （readout integrated circuit） of pixel CZT （cadmium zinc telluride） radiation detector, A high accuracy S/H circuit （sample and hold circuit） for ROIC of pixel CZT radiation detector was designed and simulated with spectre of cadence based on the model of GSMC0.18 μm. Firstly, a signal activated from preamplifier has been modeled with two current pulse signal sources. It is doped with high-frequency noise and the magnitude of the useful signal is 0.28 mV. Secondly, a performance OPAMP （operational amplifier） that is used in the S/H circuit is designed and simulated. The range of its common input is 0.6~1.4 V, and its DC Gain is 74~80 dB while its Phase Merge is more than 60°. Finally, designed a high accuracy double-phase S/H circuit, which can follow the wave of the input signal very well, and maintain its magnitude precisely with a relative error of 0.35%.