高性能TDI扫描式红外传感器读出电路研究

扫描式红外成像传感器在遥测遥感、卫星成像等远距离成像领域具有广泛的应用。为了缓解信噪比相对较低而影响图像质量的问题，提出了一种时间延时积分(TDI)型读出电路。该读出电路由电容跨阻放大器(CTIA)像素电路阵列、并行TDI电路、多路开关选择电路和输出缓冲器等组成。为实现对宽动态范围光电流的处理，CTIA电路设计有多档可选增益，且非线性度小于0.3%。该读出电路采用0.35 μm CMOS工艺设计与制造，芯片面积约为1.3 mm×20 mm，采用5 V电源时功耗小于60 mW。为了评估1024×3 TDI读出电路的功能，采用了对TDI输入端注入不同电压激励的方式进行测试，测试结果验证了所提出的设计方案。

A high performance TDI readout circuit for scanning type infrared sensor

With the increased demand for long-range imaging systems such as remote sensing and satellite imaging,scanning type infrared sensors have been deployed extensively.To alleviate the problem of relatively poor SNR that would affect the image quality,a readout circuit with a time-delayed integration (TDI) technique was proposed and described.The readout circuit consisted of capacitor trans-impedance amplifier (CTIA) pixel circuits,paralleled TDI stages,multiplexer,and output buffer.CTIA based analog front-end circuit with optional gain and less than 0.3％ nonlinearity was designed for processing large range photocurrent.The chip was manufactured with a 0.35 μm CMOS process and occupied an area of 1.3 mm×20 mm.With the 5 V power supply,the power consumption was less than 60 mW.To evaluate the function of the 1024×3 TDI readout circuit,different voltages were injected into three terminals and the output from the TDI stage was captured.The measurement results validate the proposed design successfully.