基于门控多周期积分的背景抑制读出电路

Background Suppression of Readout Circuit Based on Gated Multi-Cycle Integration(GMCI)

在空间遥感领域,波长在3?m～5?m的中红外焦平面探测器大都工作在高背景环境下,信号电流远小于背景电流。为解决当前信号淹没于背景这一突出问题,设计了一种采用门控多周期积分结构实现的背景抑制功能的读出电路。该电路在抑制背景电流(包括暗电流)的同时能有效降低噪声,提高有效积分时间,增大输出信号动态范围。经Spectre仿真软件验证了电路设计的正确性。背景电流输入范围为0 nA～110 nA,能够有效读出2.5 nA～25 nA之间的信号电流,电路输出摆幅大于2 V。该电路的设计不仅能解决当前工程中的关键问题,还对今后高性能大面阵红外焦平面高背景弱信号探测具有重要的指导意义。

In the field of spatial remote sensing,most mid-wave infrared focal plane arrays with 3-5μm wavelengths operate ina high background.The photo current is much smaller than the background current.To solve this problem,a current signal is swamped by a strong background,and a readout circuit with a background suppression function implemented with a gated multi-period integral structure is introduced.This circuit can subtract the background current(including the dark current)and reduce noise effectively while simultaneously increasing the effective integral time and dynamic range of the output signal.The effectiveness of the circuit model is verified by Spectre simulation software.Results show that the model can read signal currents between 2.5 and 25 nA effectively with a background current input range of 0 to 110 nA.In addition,the output swing of this circuit was greater than 2 V.